InspectAPedia ^TM

Mobile View
HEATING SYSTEMS
BLUERAY Recall
BOILERS, HEATING
  BOILER CONTROLS & SWITCHES
  BOILER LEAKS CORROSION STAINS
  BOILER NOISE SMOKE ODORS
  BOILER OPERATING PROBLEMS
  BOILER OPERATION DETAILS
  BOILER PARTS LIST
CARBON MONOXIDE/DIOXIDE
CARBON MONOXIDE WARNING
CHIMNEY INSPECTIONS
CHIMNEYS & Flues - Asbestos Transite Pipe
DUCT INSULATION - Asbestos Paper
DUCTS - Asbestos Transite Pipe
DUST FROM HVAC?
FURNACES
  DUCT SYSTEM DEFECTS
  FAN LIMIT SWITCH
  FURNACE CONTROLS & SWITCHES
  FURNACE OPERATION DETAILS
  HEAT EXCHANGER LEAKS
  STACK RELAY SWITCHES
GAS PIPING, VALVES, CONTROLS
HEAT LOSS INDICATORS
HEATING COST SAVINGS
HEATING LOSS DIAGNOSIS-BOILERS
HEATING LOSS DIAGNOSIS-FURNACES
HEATING OIL CLOUD WAX GEL POINT
HEATING OIL SLUDGE
HEATING SYSTEM INSPECTION GUIDE
INSULATION
NO HEAT - BOILER / FURNACE DIAGNOSIS
OIL BURNER NOISE SMOKE ODORS
OIL FUEL TYPES & CHARACTERISTICS
OIL TANK LEAKS
OIL TANK SLUDGE
OIL TANKS, BURIED
PLASTIC HEATER VENT
RADIANT HEAT Floor Mistakes to Avoid
Safety Recalls
  BLUERAY Recall
  CHIMNEYS & Flues - Asbestos Transite
  Goodman HTPV RECALL
  Lennox WARNING
  Weil McLain RECALL
SAFETY DURING HEATING INSPECTION
STEAM HEATING SYSTEMS
  Cad Cell Relay Switch Flame Sensors
  Mixing Valves
  Relief Valves - TP Valves
  Sight Glass, Steam Boiler
  Pressure Switch, Steam Boiler
  Spill Switches
  Stack Relay Switch
  Steam Vents
  LOW WATER CUTOFF CONTROLS
  WATER FEEDER VALVES
TANKLESS COILS
THERMAL TRACKING
THERMOSTATS
Transite Pipe Chimneys & Flues
More Information

InspectAPedia ^TM Home & Site Map
Air Conditioning
InspectAPedia Bookstore
Electrical
Environment
Exteriors
Heating
Home Inspection
Insulate Ventilate
Interiors
Mold Inspect/Test
Plumbing Water Septic
Roofing
Structure
Contact Us

Heating System Diagnosis, Inspection, Repair Guide
HeatAPedia ^©

	Enter your search terms Submit search form
	Search This Website - InspectAPedia.com

This website answers most questions about central heating system troubleshooting, inspection, diagnosis, and repairs. We describe how to inspect residential heating systems to inform home owners, buyers, and home inspectors of common heating system defects. The articles at this website describe the basic components of a home heating system, how to find the rated heating capacity of an heating system by examining various data tags and components, how to recognize common heating system operating or safety defects, and how to save money on home heating costs. We include product safety recall and other heating system hazards. The limitations of visual inspection of heating systems are described. We continue to add to and update this text as new details are provided. Contact us to suggest text changes and additions and, if you wish, to receive online listing and credit for that contribution. © Copyright 2008 Daniel Friedman, All Rights Reserved. Information Accuracy & Bias Pledge is at below-left. Use the links at page left to navigate this document or to go to Other Website Topics. Green links at left show where you are in our document & website.

How to Inspect Heating Systems - Example of An Approach to the Forensic Inspection of Any Complex System

This document presents a detailed methodology for inspecting, diagnosing, & repairing defects on residential heating systems with attention to inspection methods selected to assure completeness, accuracy, and the maximum level of defect detection. The heating system inspection methodology described here serves as a guide to the forensic diagnostic inspection of any complex system where the highest probability of detecting important safety or operating defects is important. The photograph shows a severely rusted tankless coil mounted on a steel heating boiler. If the coil-mounting surface on the boiler itself is severely rusted it may be necessary to replace the entire heating boiler. While a welder could weld on a new mounting surface for a new coil, none of the repairmen are likely to warrant such a "fix" and further, the welder, knowing that the owner is facing the cost of a whole new boiler, is likely to set a high fee for even attempting the repair. It is important to recognize and report the significance of rust like this on a heating boiler. At this website we describe organized procedures for inspecting complex systems for defects, using the organized step by step method to assure inspection heating system inspection completeness and accuracy but without losing the ability to discover unexpected problems as well.

© Copyright Daniel Friedman 2008-1993 all rights reserved -- Tri-State ASHI Home Inspection Education Seminar - Initial Presentation November 6-7, 1993 -- Last update 11/10/2007

How to Relate Heating System Inspection Procedures to Home Inspection Standards of Practice

This presentation follows a procedure for inspecting, using heating system operating sequence as a method to assure that all important system components are considered. A version of the ASHI Standards of Home Inspection Practice (readers should check most recent Standards version for changes) is mapped into this heating system inspection procedure but does not guide the actual inspection sequence. The organization of home inspection standards is not intended as a guide to an inspection sequence nor as a guide to heating system inspection reports. Home Inspection Standards requirements during the inspection of a home heating system are identified in italics in the text below.

HEATING INSPECTION CONCEPTS - How to Select an Inspection Methodology for Heating System Inspection & Diagnosis

Step 1: Select a Heating System Inspection Road Map to Guide the Inspection Sequence

In order to be as thorough, accurate, and safe as possible, a heating system inspector should use a well-defined order of discovery which assures that s/he examines all important heating system components. Several possible heating system inspection "road maps" can be used for this purpose. Two approaches inspect the heating equipment by physical layout of components, or by inspecting the heating system in the detailed order that it will operate during the heating system operating cycle.

Of these "heating system inspection road maps", the first of these inspection methods is physically convenient, that is: inspect each heating system component where each is located in each building area, and this is the most common approach in use in the field. But but it is the second option, heating boiler or furnace operating sequence, that best assures that the inspector considers proper system operation and that s/he identifies all of the system components.

Thinking thorough the sequence of steps in operation of a home heating system requires that the inspector understand how heating systems work. An inspector who cannot follow this sequence does not understand heating system operation and is rather likely to miss important system defects.

So how should a heating system be inspected? For efficiency the inspector may decide to examine each system component as s/he enters the area of the building where that component resides. So all heater components in the basement or crawl space are examined in one pass while the inspector is in that area, and so on. But in thinking about the completeness and accuracy of the heating system check the inspector should also think through the system's operating sequence, using the components identified in that sequence to assure that s/he has not omitted something important. Why is this second thought pattern needed? Because it is always easier to inspect and think about a building component that we see than to think about a component that is simply absent. In other words, if there is no temperature or pressure relief valve to see on a boiler, the inspector may fail to think about whether or not this is a serious safety hazard for the particular installation.

How to Inspect a Heating System using Physical Location of Components

This approach broadens the scope of the heating system inspection and it may aid in heating system defect recognition or problem diagnosis, for example by observing that a heating boiler is located in a small, air-tight room (possible combustion air problems), or that the furnace is quite close to the oil storage tank.

• Identify the heating system components in each building area.
• At the heating boiler or furnace, identify the fuel source and follow fuel supply piping to its source (an oil tank, LP gas tank, or gas meter, for example).
• At the boiler or furnace, identify the heat distribution method and follow the delivery of heat (warm air or hot water) leaving the furnace or boiler, and returning to it. Failure to consider this whole path logically risks failing to notice potential problems such as return air taken at a furnace itself or the absence of adequate return air.
• At the boiler or furnace identify each of the controls and safety devices and observe their condition. Those devices that are intended for normal operation by the home owner are usually also operated and tested by the inspector. Other devices such as temperature/pressure relief valves are not normally operated but are visually inspected for evidence of a problem.

How to Inspect a Heating System Using the Sequence of Heating System Operation

This approach to heating system inspection Identifies most components of heating systems or of other mechanical systems and is most likely to give the most complete list system parts. It helps assure that all critical components are considered. Actual observation of heating system operation is important in enabling the inspector to identify malfunctions. The heating boiler or furnace inspector's field procedure should include this aid.

A detailed example of the steps in the sequence of operation of a heating system along with a detailed list of heating system components is provided below at Sample Inspection Procedure for Heating Equipment.

The Importance of Reporting to the Client the Significance of Heating System Defects

A superficial heating system inspection may simply identify the type of system present and perhaps the presence of obvious visual anomalies such as leaks. But an astute inspector understands more thoroughly the implications for safety or function of the defects that s/he observes and thus is more likely to inspect the heating system more thoroughly and is more likely to report the inspection findings in a meaningful way to the client.

It is essential that a heating system inspector clearly communicate to the client the significance of the inspection results. In other words, the client should be given to understand the need for action, or urgent action, the presence of unsafe conditions, or the indications that costly repairs or replacement are likely to be needed immediately or in the coming year or before next heating season.

The Importance of Thinking about the Possible Significance of Home Inspection Observations

Here are two examples of the difference between simply reporting a home inspection observation neutrally and thinking about the significance of a home inspection observation in a way that might lead to discovery of something important about a heating system.

Example Outdoor Inspection Observation: drip lines below roof eaves

Observation: The heating system inspector, before entering the home, observes outside that there are deep drip lines in the soil below the home's roof eaves. Drip lines indicate that there has been long term poor control of roof runoff.
Interpretation: there may have been a history of wet basement conditions.
Implications: especially if the home is heated by a furnace located in the basement or crawl space, watch out for signs of rusting of the furnace heat exchanger, particularly in steel hot-air furnaces. A rusted and thus leaky furnace heat exchanger is a possibly dangerous condition, risking high Carbon Monoxide CO levels in the building - a condition that can lead to a fatality - someone could die.
Action: look inside for corroborating clues first of water entry and second of rust on the furnace or its components. Test or recommend testing of heat exchanger for leaks and safety.

An Example of Neutral (irresponsible) home inspection reporting of heating system condition

Outside we observed roof overflow or drip lines below the house eaves.

Inside, A BrandX natural-gas fired 90,000 BTUH steel hot air furnace heating system is installed. The system appears to be 20 years old. In response to turning up the heat we observed that the system operated normally: heat came out of the air supply registers. (Our inspection excludes heating system disassembly and therefore cannot examine the condition of the furnace interior components. You should have the system inspected by a qualified technician.) What's wrong with this report is that it does not explaing that drip lines under gutters mean that there has been a history of gutter overflow, poor maintenance, and a risk of water entry in the building. Worse, the report make clear that there are special reasons to be concerned about the reliability and safety of this heating system and there is no clue that costly replacement could be needed.

An Example of More-responsible home inspection reporting of heating system condition

Outside we observed roof overflow or drip lines below the house eaves. This means that water has been spilling by the house foundation for a long time, that roof gutters and downspouts are needed, and that the home may have been exposed to a history of water entry or leaks which in turn could cause problems indoors.

Inside, A BrandX natural-gas fired 90,000 BTUH steel hot air furnace heating system is installed. In response to turning up the heat we observed that the system operated normally: heat came out of the air supply registers. (Our inspection excludes heating system disassembly and therefore cannot examine the condition of the furnace interior components. The system appears to be 20 years old and based on age alone is likely to be at or near the end of its useful life - significant expense will be involved when furnace replacement is needed.

In response to turning up the heat we observed that the system operated normally: heat came out of the air supply registers. Our inspection excludes heating system disassembly and therefore cannot fully examine the condition of the furnace interior components.

However, we observed heavy rust on the bottom of the furnace and other evidence of a history of water entry in the basement. A furnace exposed to these conditions is at extra risk of hidden rust damage such which could include a leaky heat exchanger. If the heat exchanger is leaking this heating system would be unsafe, should not be used, and would almost certainly require immediate replacement - a significant expense.

Heating System Inspection Methodology

How to Inspect Heating Systems - as An Approach to the Forensic Inspection of Any Complex System

	Enter your search terms Submit search form
	Search This Website - InspectAPedia.com

This sounds fancier than intended. Our object is to use an organized procedure for inspecting for defects, without losing the ability to discover unexpected problems as well.

The methodology discussed includes both details specific to heating boilers (the full outline at "Contents") and more general complex-system inspection methods (listed immediately below). © Copyright 2008 Daniel Friedman, All Rights Reserved. Information Accuracy & Bias Pledge is at below-left. Use the links at page left to navigate this document or to go to Other Website Topics. Green links at left show where you are in our document & website.

© Copyright Daniel Friedman 2006-1993 all rights reserved -- Tri-State ASHI Seminar -- Last update 04/11/2007 (minor modifications in root page) - first presentation November 6-7, 1993

How to Inspect Residential Heating Systems - Contents

1. ASHI Standards of Practice for Inspecting Heating Systems
2. Choosing an Inspection Methodology
1. Step 1: Select a "road map"
1. Order of Construction of the heating system
2. Physical Layout of the heating system
3. Sequence of Operation of the heating system
4. Implications of Defects of the heating system for safety or operation
5. For effective examination of any complex structure, the professional uses all of these tools.
2. Step 2: Select the appropriate "viewpoint"
3. Step 3: Observe and record potential defects>
1. What should you look for when inspecting a heating system?
2. What do your heating system observations mean?
3. Heating boiler or furnace equipment examples:
3. A Detailed Inspection Procedure for Heating Equipment
1. Before the heating system inspection
2. At the office - when order is taken (*)
3. Driving to the inspection
4. A HREF="http://www.inspect-ny.com/heat/HeatingSys.htm#arriving">Arriving at the inspection--MORE PREPARATION
1. Relax
2. Take Control of the Inspection
3. Pay Attention, avoid distractions
4. Use techniques to stay focused, to avoid mistakes
5. Outside Observations--EXECUTION
1. Type of heating Equipment Installed
2. Heating Fuel type and storage location
3. Heating system Venting and possible hazards noted from outside
4. Potential Heating system issues
5. Heating System Operation notes taken from outside
6. Inside Observations
1. Observing the Heating System In the living area
2. Observing the Heating System components In the utility room
4. How to Inspect Oil-Fired Hot Water Boiler Heating Systems
1. Inspect before operating the boiler
2. Examine Heating System components in the sequence of operation
3. Look closely at controls, peripherals, key components,
1. Heating System Leaks and Corrosion on Heating Systems - implications
1. Common leak locations
• Examples of understanding function and implications
• Different operating sequence views
• Different controls, more costly:
• Example of understanding function=understanding implications
4. Detailed Examination of Furnaces side topic
5. Final checks in the Heating System boiler room
1. Operate the equipment
1. Heating Boiler Defects Observed During Operation
2. Possible thought sequences for final check of the boiler
6. Heating Inspection Safety Concerns for the Home Inspector
7. More Information on Inspecting and Repairing Heating Systems

Contents

ASHI Standards of Practice regarding Heating System Inspections

• Are for consumers, to assure completeness of coverage of topic.
• Are not a procedural guide for the actual inspection
• Are not a technically comprehensive list of components that must be considered
• Are not a comprehensive list of defects to be detected
• Do not define pass-fail criteria for components inspected
• Do not identify the implications of defects for other systems or components

This presentation follows a procedure for inspecting, using heating system operating sequence as a method to assure that all important system components are considered. A version of the ASHI Standards of Practice (readers should check most recent Standards version for changes) is mapped into the procedure but do not guide its sequence. The organization of the Standards is not intended as a guide to an inspection sequence nor as a guide to reporting sequence. ASHI Standards requirements are identified in italics in the text below.

Contents

Choosing an Inspection Methodology

Step 1: Select a "road map"

Order of Construction

• identifies Heating System components
• aids in diagnosis of what happened when and why
• particularly helpful for structural anomalies

Heating System Physical Layout

• broadens scope of inspection
• may aid in diagnosis

Heating System Sequence of Operation

• identifies most components of mechanical systems, helps assure all critical components are considered. (Actual operation helps identify malfunctions.)
• a methodology for inspecting mechanical systems should include this aid

Implications of Heating System Defects

• broadens the search to other components. Reminds the inspector to explain what the defect means to the client.
• all inspection topics must this aid
• E.G. Observation: deep drip lines below eaves-long term poor control of roof runoff.
  Interpretation: possible wet basement conditions--watch for rusting of heat exchanger in steel hot-air furnaces.
  Implications: possibly dangerous conditions including high CO levels in the building.
  Action: look inside for corroborating clues: wet basement, rust on furnace. Test or recommend test of heat exchanger.

For effective examination of any complex structure, the professional uses all of these tools.

Addressing the question of completeness of coverage of components, for a thought-guide to inspecting heating equipment we selected Sequence of Operation as a model.

Step 2: Select the appropriate "viewpoint"

• Broad/distant (is the building tipping?)
• Close/detailed (is the railing newell base lag bolt missing?)
• Combined broad and detailed views

For home inspections, because many building systems and conditions affect one another, a broad view is appropriate for most topics, even where a detailed examination is always made.

Step 3: Observe and record potential defects

• Apply a well-defined methodology using:
• Heating System Distant views
• Heating System Detailed views
• Heating System Final distant views

What should you look for when inspecting a Heating System ?

• Improper construction/installation
• Improper Heating System function
• Heating System Damage
• Missing Heating System components
• Clues of potential Heating System defects

What do your Heating System observations mean?

• think about remote impacts on other systems

Heating equipment examples:

• leaky oil at transformer--watch for back pressure in combustion chamber--watch out for blocked heating flue or blocked chimney
• Unusual interior moisture conditions or odors during heating season--watch for blocked chimney or poor flue vent connections
• Specific problem brands Repco, Blueray etc.
• Blueray Heating Boilers/Furnaces Safety Recall by the US CPSC, with additional history, photos, and technical details; Blue Flame Blue Ray
• Carbon Dioxide Gas Toxicity
• Carbon Monoxide Gas Toxicity, exposure limits, building inspection for CO hazards
• Dust from HVAC? An Investigation of Indoor Dust Debris Blamed on a Heating/Cooling System Reveals Carpet Dust
• Goodman Furnace High Temperature Plastic Vent HTPV safety recall US CPSC notice
• Home Heating System Should Be Checked [for proper venting and for CO Carbon Monoxide Hazards - DJF]
• Inspection Procedures for Oil-Fired Heating Systems Detailed step by step approaches for inspecting complex systems]
• Lennox Pulse Furnace Safety Inspection/Warranty Program: Carbon Monoxide Warning
• Oil Tanks - The Oil Storage Tank Information Website: Buried or Above Ground Oil Tank Inspection, Testing, Cleanup, Abandonment of Oil Tanks
• Oil Tanks Above Ground, UL Standards, guidance for home owners, buyers, and inspectors
• Home Inspection Report Language Library: Gas Fuel Piping or Tank Faults Basic advice - home inspection report language suggestions
• Home Inspection Report Language Library: Buried Oil Tanks, Basic home buyer advice - home inspection report language suggestions
• Home Inspection Report Language Library: Defects in Oil Tank Installations, Tanks, and Heating Oil Piping
• Plastic Heating Vent Pipe & Other Heating Safety Recall Notices
• Weil McLain Model GV Gas Boiler/gas valve CPSC recall/repair

Contents

Sample Inspection Procedure for Heating Equipment

Before the inspection

At the office - when order is taken (*)

• Age of house--how old might the equipment be?
• Location (neighborhood)--is it a builder's development with all boilers of a particular problem-brand?
• Price range--is it a higher priced house likely to have more costly equipment/multiple systems?
• Type of house--large "H" ranch (one story) may have two separate furnaces
• Buyer's concerns--comments about heating system volunteered by client?
• House is occupied? winterized system, has it been left on?
• Was work done by seller or amateurs? IE: "the owner converted the basement" [and did heating and electrical work?]

Driving to the inspection

• Rested, healthy, attentive, mind on work?
• If not, recognize that extra effort will be needed to tune your attention to the task about to begin.
• Do not perform an inspection if you are seriously ill or distracted. Life-safety issues may be missed.
• Turn off the radio a mile or so before reaching the house.
• Think about the process.
• Tune your mind to the task at hand.
• Quiet time.
• Observe the neighborhood, age of houses, quality of maintenance, heavy trees (funny winds and flue draft problems or squirrels in chimneys).

Contents

Arriving at the inspection--MORE PREPARATION:

Relax

• Turn off the car ignition.
• Exhale fully.
• Calm yourself for a moment before getting out of the car, before stepping into the sea of seller and buyer anxiety and sometimes the cold acrid wind of realtor fear.

Take Control

• The inspector must be in control of the process.
• Do not permit distractions. Focus must be on the house, then on clients to assure your explanations are understood.

Pay Attention

• Home inspection is paying attention to everything, simultaneously. Each observation at every step might reveal a key which will trigger an important discovery later in the inspection.
• The inspector must focus on a sequence of examination of minute details.
• Simultaneously the inspector must remain open to the unexpected findings or ideas. The unexpected may be suggested by a detail under examination or it may intrude from the inspector's peripheral.
• It is easier to notice the presence of a defect of commission (leaking relief valve) than a defect of omission (no relief valve installed). "Psychology and nothing," Eliot Hearst, American Scientist, Sept.-Oct. 1991 pp 432-443. Every home inspector can improve his/her inspection technique by reading this article. Recognizing and learning from absence, deletion, and nonoccurrence are surprisingly difficult. Thinking through sequences of construction or of operation of equipment can help find omissions.

Use techniques to stay focused, to avoid mistakes,

• Practice a balance between an orderly method or procedure which assures completeness and sufficient random steps in the process to avoid becoming routinized. Otherwise the inspector will observe only what's on the checklist and may miss glaring defects. Inspect the house and use your checklist to record it easily. Do not fit the house to the checklist.
• Once your procedure is well established and familiar you should deliberately vary some of its components at every inspection. Change an order, reverse a sequence.

Contents

Outside Observations--EXECUTION

Type of Equipment Installed

Fuel

Venting and possible hazards noted from outside:

If there is no chimney cap

• is flue blocked by debris?
• has wind-blown rain damaged the masonry interior?
• has wind-blown rain run down chimney into flue vent piping and on into the equipment?
• Did it cause rust damage? Fire chamber damage?

Masonry chimneys

• damaged flue liner? Damage by condensation, frost, acid rain, sulphation (especially with gas-burning equipment)
• Loose bricks?
• Unlined single-wythe brick flues (still common in large cities)--if damaged, risk of fire, leaking flue gases, blocked flues. Look further in the attic and assure there's a cleanout or suggest vent connector be pulled to check for blockage.

Old stone chimneys

• often stop at foundation, heaters were added, connected in to very base of chimney - easily blocked by fallen debris.
• Signs of history of water entry (risk unsafe flue: blocked, fire risks - falling debris
• possible damaged heating equipment (more likely for furnaces than boilers)

Potential issues

System Operation notes taken from outside:

• Sooty chimney top or soot stains on roof: system has not been operating properly
• Soot washed off: system may have been repaired/replaced
• Soot heavy and fresh or smoky exhaust seen, system currently needs service or repair
• Watch out for Repco boilers which run sooty as they crash.
• Heat seen rising from heating flue in July - the house may have a tankless coil for domestic hot water. If not, is the primary control set up properly?
• Is there a separate oil-fired water heater using same flue? What's running making that exhaust? Reserve questions for later.

Contents

Inside Observations

Viewpoint #2--Distant view of the heating equipment from the living area.

In the living area

Type of Heat Distribution
ASHI 9.1.A.7 the presence of an installed heat source in each room. ASHI 9.3.D.4 The inspector is not required to observe the uniformity of heat supply to various rooms.

• Air registers: hot-air furnace. Begin looking for supply and return grilles. Identification tip: return grilles often have no controlling louvers and may be centrally located. Distribution problems are not discussed in this presentation.
• Baseboards - electric or hot water.
• Radiators - hot water or steam. Steam: observe steam valves on each radiator and identify one pipe vs two-pipe distribution system.
• Nothing visible: is there electric or hot water radiant heat. Watch for multiple types of heat supply: e.g.: baseboards, with electric heaters in bathrooms.

In the utility room

Viewpoint #3--Distant broad view of the heating equipment from the utility room. The Heating System equipment is directly in view but not yet closely examined.
ASHI 9.1.A. The Inspector shall observe permanently installed heating systems including: [items are listed later]
ASHI 9.2.A.2 The inspector shall describe heating equipment and distribution type

1. Identify/confirm type of equipment
2. Housekeeping, location of combustibles
3. Air supply
4. Sooty operation, odors, noises
5. Evidence of recent maintenance
6. Service tags vs filth atop the equipment or in the chimney was it really serviced?

Contents

Detailed Examination of Oil-Fired Hot Water Boilers

Viewpoint #4--Detailed close scrutiny of the equipment, after a few "sanity checks"
ASHI 9.1.A.1 The inspector shall observe ... heating equipment

Inspect before operating the boiler

What are we looking at? Form a working Definition: A system which heats the house. A steel, copper, or cast iron "box" of hot water, connected to a loop of pipe (and radiators or baseboards) which runs around through the living area. The same physical water stays in the boiler and is circulated by a pump so that heat is delivered to the living area. Burning oil makes hot gases which are used to heat the water before being exhausted outside. Pumps move fluids. Safety controls at various points protect against a number of potential hazards.

• Do you see some reason not to turn this Heating System on? (See Safety Concerns for the Home Inspector below.) What about other problems?
• Is the system safely connected to a chimney?
• Look at the temperature/pressure gauge: normal operating values?
• Look for leaks in the boiler itself (Cast iron is more resistant to death by leaks than steel. Older cast iron systems without tankless coils, if shut off in summer, may be at risk of leakage and hidden damage. Steel rusts through. Cast iron cracks or leaks at joints.)
• Look for leaks at controls now and again in the sequence below
• Leaks at valves or fittings which drip into the jacket of a steel boiler or onto controls or zone valves risk failure and loss of heat.
• Is there a tankless coil? If so, address both topics, looking at heating first, DHW second.

Contents

Examine components in the sequence of operation

Examine the accessible parts of the system. Let your eye travel from component to component in the sequence of operation. Apply the inspection logic discussed earlier, at each step. Consider the implications should each component be missing, damaged, inoperative, leaky, noisy, sooty, repaired by an amateur, etc. Think through the operating sequence as you examine each component in that order. The following are the steps in one common set-up. This list is lengthy and detailed. The actual visual examination may take only a few minutes.

1. Room temperature drops,
2. room thermostat switches "on" ASHI 9.1.A.2 normal operating controls
3. [zone valve opens and] circulator [starts] [except in Canada where circulators may be set up to run continuously and where the thermostat directly turns on the oil burner] [Circulator usually located on cooler return-side of the distribution piping loop-longer life.]
4. boiler temperature and pressure are indicated on the TP gauge and should show increase not to exceed normal operating limits (200 deg F or less and less than 30 psi)
5. hot heating water leaves boiler passing by the ...
6. air scoop (not always present; avoids air-bound baseboards)
7. [air purge] (not always present; often leaky or sealed off)
8. [automatic] water feeder (normally the manual valve for water supply to boiler is "on", the automatic valve is closed unless the boiler pressure drops below 12-15 psi.This valve is often also a backflow-preventer.)
9. expansion tank (waterlogged, dumping relief valve)(attic? no r v?=some old equipment)
10. [zone valve] (not always used, shorter life on the "hot" supply side of <->piping)
11. distribution piping (watch for mineral salts indicating small clogged leaks)
12. baseboards - which warm the room and thus the ... ASHI 9.1.A.6 heat distribution systems including fans, pumps, ducts and piping with supports, dampers, insulation, air filters, registers, radiators, fan-coil units, convectors
13. room thermostat senses the heat increase. Water passes
14. more distribution piping returning to boiler past
15. zone service drain and [flow balancing valves] (are they leaky?)
16. [circulator pump] (if it's not a convection system used on older houses)
17. back into the boiler.
18. temperature in the boiler drops as cooler water returns.
19. temperature sensor feels the temp drop and tells the ...
20. primary control or high-limit control, but nothing happens (in the U.S.) until ...
21. temperature drops 15 deg F below the HI setting on the primary control. Then the
22. primary control turns on the oil burner (any drip/leak damage onto the control?) (Canadian systems: thermostat may activate burner directly.)
23. burner pumps oil from the tank through ... (did we see the tank? is there an oil filter?)
24. [copper] fuel line (and possibly sends excess back through a return line)
25. [past one or more Fire-o-Matic safety valves] (fusible link used in some jurisdictions) through the pump unit, sending ...
26. high pressure oil to burner nozzle for spray into fire chamber (chamber ok?)
27. transformer makes high voltage sent as spark to ignite oil (tar ooze at transformer?) and ...
28. blower unit sends combustion air into the fire chamber... (is there adequate combustion air? how about when the boiler room door is closed?)
29. Oil begins to burn (rough start or poor shut-down? smoke, soot, odor, noise ?)
30. hot gases pass through tubes in steel or between sections in cast iron boiler, sending heat back into the heating water through the heat exchanger. (soot acts as insulation--boiler cleaned recently?)
31. hot gases are collected at top of boiler and sent out through exhaust flue ...
32. where the barometric damper assures proper and even draft; hot gases continue ..., up
33. up the chimney to outdoors.
    ASHI 9.1.A.4 chimneys, flues, and vents (is the chimney improperly shared or vented to multiple floors?) ASHI 9.1.A.5 solid fuel heating devices [e.g. wood and coal stoves]
34. boiler temperature rises up to the "HI" limit. (Thinking of High take a look for a pressure relief valve and look for defects there: leaking, corroded, not piped to floor, reduced diameter piping.)
35. sensor informs Primary Control which turns off the burner-(sloppy shut down?) (Circulator is continuing to run)
36. the room is warm enough according to the thermostat so the ...
37. thermostat senses the temperature rise and opens its switch. (Special thermostat sophistication and functions excluded here)
38. circulator stops (except in Toronto)
39. burner will either stop then or continue until HI limit is reached.

Contents

Look closely at controls, peripherals, key components,

• Combination control - combining High Limit and "Low Limit" (which may or may not be in use depending on presence of a tankless coil)
• High Limit and Low Limit (if tankless coil) separate controls on older equipment
• Flame sensing device: Cad Cell or Stack Relay (watch for sensitive relays and learn about the re-stepping lever)
• Automatic water feeder and Expansion Tank
• Pressure Relief Valve
• Pressure and Temperature gauge--12 psi cold, less than 30 psi hot. Over 30 psi dumps relief valve.(Typical operating temperature settings LO-120-160 HI-180-200 degF. Typical operating temperature observed at the gauge will be below the high, and can be as low as nighttime room temperature in non-heating season if no tankless coil is in use. The temperature/pressure gauge may help in checking for normal conditions before and during boiler operation. However the gauge can be wrong!)
• Tankless coil--leaks, missing mixing/tempering valve, relief valve (some jurisdictions). Risk of scalding water at the house sinks/tubs if there is no mixing valve.

Leaks and Corrosion - some implications

• Surface rust--repairable. Clean when serviced and monitor
• Exfoliation--very serious, possibly not repairable, risks loss of boiler.

Common leak locations

• Coil mounting plate - see rust stains below and around plate
• Pipe fittings at face of coil plate - mineral salts
• Leaks around bolt openings - suspect hidden damage

Examples of understanding function and implications:

• Leaks are never acceptable, anywhere. Leaking relief valves need immediate attention and repair (Leaking relief valve could be due to water-logged expansion tank, improper control settings (temp too high), improper automatic water feeder operation (pressure too high), or defective valve (leaky). True, you only have to report the valve. Did you miss problems at the other components?) Corroded relief valves also need test and repair/replacement
  Do not touch the relief valve- it may open and fail to shut down.
  Do not pick at corrosion as you may start a catastrophic, un-stoppable leak requiring total system shut-down.
• Different water pressure/flow observed in the kitchen: hot water pressure significantly less than cold--is a tankless coil installed? is a water softener installed? is there "hard" water--have mineral deposits clogged the coil? Are there "cleanout" plumbing fittings on the coil piping? Does this suggest a history of clogging and acid-flush treatments? Can a clogged coil be repaired or replaced? How severe was that rust you observed at the coil mounting plate?

Different Heating System Operating Sequence

Eg: immediate burner on when the thermostat is turned-on from the living area.

Different Heating System Controls, more costly:

• Air vents at radiators,
• Pressure switch at boiler, typically set to .2 to .5 psi
• Lower-pressure relief valve
• Water feeder, manual or automatic. (Don't mess with either, they may open and be hard to shut off.)
• Low Water Cutoff on some systems. (Also found on some hydronic boilers.)
• Different piping on some systems - one-pipe vs two-pipe, easy to identify and very different implications for retrofit/conversion to other heating methods such as hot water.
• Immediately recognized from the living area by presence of steam valves on radiators. Don't confuse steam valve with air bleeder valves found on hot water radiators.
• Steam rises--hence no circulator pump - if you see a pump is it a separate HW zone? is it a condensate return pump?

Contents

Example of understanding function=understanding implications

Absence of any sign that the occupants ever drain and clean the automatic water feeder suggests risk of inoperative key safety device. Needs attention even if you see absolutely no problems. Modified piping? improperly sloped radiators?

Contents

Furnaces - Hot Air Heating System Inspection

• A simpler, operating sequence
• Different controls-- blower, fan/limit sw.
• Working Definition: A furnace is a steel or cast iron "box" connected to a series of duct work which runs through the house bringing hot air to grilles (registers). A fan, usually at the furnace, circulates air from cold-air return grilles through duct work to the furnace where the air is heated and then returned through "supply ducts" to the living area.
• Room cools, thermostat switch closes (calls for heat), oil burner is turned on, oil is pumped from tank to burner, ignited, burned,
• Hot gases pass through a fire chamber (steel can) and out an exhaust flue, past a barometric damper to a chimney to outdoors.
• ASHI 9.2.C. The inspector shall open readily open-able access panels provided by the manufacturer or installer for routine homeowner maintenance
• Understanding functions=understanding implications: eg: wet basement, steel furnace, high CO risks from rusted heat exchanger.

Contents

Final checks in the boiler room:

Operate the equipment

Operating defects:

• Noises, smoke, soot, back pressure at inspection port (watch out for burns and fires if this port is opened), sloppy startup, rumbling, sloppy or delayed shutdown-flame lingers (very dangerous).
• Feeling piping (hot!) can indicate if circulator is running--quick change in temperature vs convection.
• Some leaks occur only at peak operating temperature--eg at relief valve.
• Startup problems: noises, puff back, flapping barometric damper, vibrations
• Particularly in cold weather, if the system was on and running, observe and note that it was running normally when you last touched it. Witnessed. (Frost damage issues lurk here.)

Possible thought sequences for final check

• Hot heating water movement from house supply into boiler, through circulating equipment.
• Fuel movement from tank through burner up flue and chimney.
• Air movement into house and to burner and up flue and chimney.
• Air movement inside duct work (for furnaces)
• Complete operation sequence reviewed?
• Other building conditions observed which raise questions?
  wet basement, poor housekeeping, poor maintenance, extensive building additions may stretch boiler capacity, ...
• What's missing ?
• Did we leave the system operating normally?

Contents

Heating Inspections: Safety Concerns for the Home Inspector

• Do not turn on equipment which has been "shut down" - Possible open piping, unsafe wiring, leaks, unsafe chimney, fire risks.
• Do not turn on equipment which has been switched off without explicit permission/instruction from a responsible party
• Examine gauges (not entirely reliable) for unusual pressure or temperature conditions and do not permit such equipment to continue to operate
• Do not operate equipment which does not appear to be vented properly; shut down equipment if, on operating it, you observe an apparently blocked flue
• Do not operate equipment if the chimney is suspect--e.g. old single wythe unlined brick with visible damage in the attic or outside
• Watch for flashback at inspection ports
• Watch for electric shock at controls
• Do not pick at corrosion
• Do not test relief valve levers nor catch your sleeve on one
  ASHI 9.3.B. The inspector is not required to operate automatic safety controls
• Do not light fires in coal or wood stoves to check draft, etc
  ASHI 9.3.C. The inspector is not required to ignite or extinguish solid fuel fires
• Do not disassemble flue vent piping - risks of filth, unable to reassemble, etc.
  ASHI 9.3.D.1 The inspector is not required to observe the interior of flues [However often you can detect a blocked flue by looking through the barometric damper or by use of a mirror at the chimney cleanout. We recommend this step. -DJF]
  ASHI 9.3.D.2 The inspector is not required to observe fireplace insert flue connections [Normally not visible. Caution: there is frequently a hidden problem there.]
• Be careful about disconnecting humidifiers to obtain access to furnace plenums: you may cut yourself on sheet metal, cause leaks in humidifier piping, cause spills.
  ASHI 9.3.D.3 The inspector is not required to observe humidifiers
• But watch for humidifiers which leaked into and damaged duct work or onto and damaged a heat exchanger.
• Avoid electric shock from the static charge at electronic air filters.
  ASHI 9.3.D.4 The inspector is not required to observe electronic air filters

Contents

Sick Building Sick House Investigations, allergy, allergies, allergens, asthma, asthmatics, dust mites, mold, mildew, fungi, indoor Electromagnetic radiation fields, environmental hazards residential properties for home buyers home owners contamination Cooling air quality, heating system ventilation, combustion air, chimney defects, moisture, water entry, wet basements, surface and roof drainage, flooding, water damage,air quality measurements ASHI American Society of Home Inspectors Air (C)trap Daniel Friedman, Conditioning Asbestos Construction failures Heating drinking water contamination contaminants lead, pesticides, organics lead paint hazard advice, testing Underground Storage UST professional ASHI home inspections inspectors

More expert information on this topic

More Information on Inspecting and Repairing Heating Systems

• Carbon Dioxide Gas Toxicity
• Carbon Monoxide Gas Toxicity, exposure limits, poisoning symptoms, and inspecting buildings for CO hazards
• Dust from HVAC? An Investigation of Indoor Dust Debris Blamed on a Heating/Cooling System Reveals Carpet Dust
• Goodman Furnace High Temperature Plastic Vent HTPV safety recall US CPSC notice
• Home Heating System Should Be Checked [for proper venting and for CO Carbon Monoxide Hazards - DJF]
• Inspection Procedures for Oil-Fired Heating Systems Detailed step by step approaches for inspecting complex systems]
• Lennox Pulse Furnace Safety Inspection/Warranty Program: Carbon Monoxide Warning
• Oil Tanks - The Oil Storage Tank Information Website: Buried or Above Ground Oil Tank Inspection, Testing, Cleanup, Abandonment of Oil Tanks
• Oil Tanks Above Ground, UL Standards, guidance for home owners, buyers, and inspectors
• Plastic Heating Vent Pipe & Other Heating Safety Recall Notices
• Weil McLain Model GV Gas Boiler/gas valve CPSC recall/repair
• Domestic and Commercial Oil Burners, Charles H. Burkhardt, McGraw Hill Book Company, New York 3rd Ed 1969.
• National Fuel Gas Code (Z223.1) $16.00 and National Fuel Gas Code Handbook (Z223.2) $47.00 American Gas Association (A.G.A.), 1515 Wilson Boulevard, Arlington, VA 22209 also available from National Fire Protection Association, Batterymarch Park, Quincy, MA 02269. Fundamentals of Gas Appliance Venting and Ventilation, 1985, American Gas Association Laboratories, Engineering Services Department. American Gas Association, 1515 Wilson Boulevard, Arlington, VA 22209. Catalog #XHO585. Reprinted 1989.
• The Steam Book, 1984, Training and Education Department, Fluid Handling Division, ITT [probably out of print, possibly available from several home inspection supply companies] Fuel Oil and Oil Heat Magazine, October 1990, offers an update,
• Principles of Steam Heating, $13.25 includes postage. Fuel oil & Oil Heat Magazine, 389 Passaic Ave., Fairfield, NJ 07004.
• The Lost Art of Steam Heating, Dan Holohan, 516-579-3046 FAX
• Principles of Steam Heating, Dan Holohan, technical editor of Fuel Oil and Oil Heat magazine, 389 Passaic Ave., Fairfield, NJ 07004 ($12.+1.25 postage/handling).
• "Residential Steam Heating Systems", Instructional Technologies Institute, Inc., 145 "D" Grassy Plain St., Bethel, CT 06801 800/227-1663 [home inspection training material] 1987
• "Residential Hydronic (circulating hot water) Heating Systems", Instructional Technologies Institute, Inc., 145 "D" Grassy Plain St., Bethel, CT 06801 800/227-1663 [home inspection training material] 1987
• "Warm Air Heating Systems". Instructional Technologies Institute, Inc., 145 "D" Grassy Plain St., Bethel, CT 06801 800/227-1663 [home inspection training material] 1987
• Heating, Ventilating, and Air Conditioning Volume I, Heating Fundamentals,
• Boilers, Boiler Conversions, James E. Brumbaugh, ISBN 0-672-23389-4 (v. 1) Volume II, Oil, Gas, and Coal Burners, Controls, Ducts, Piping, Valves, James E. Brumbaugh, ISBN 0-672-23390-7 (v. 2) Volume III, Radiant Heating, Water Heaters, Ventilation, Air Conditioning, Heat Pumps, Air Cleaners, James E. Brumbaugh, ISBN 0-672-23383-5 (v. 3) or ISBN 0-672-23380-0 (set) Special Sales Director, Macmillan Publishing Co., 866 Third Ave., New York, NY 10022. Macmillan Publishing Co., NY
• Installation Guide for Residential Hydronic Heating Systems
• Installation Guide #200, The Hydronics Institute, 35 Russo Place, Berkeley Heights, NJ 07922
• The ABC's of Retention Head Oil Burners, National Association of Oil Heat Service Managers, TM 115, National Old Timers' Association of the Energy Industry, PO Box 168, Mineola, NY 11501. (Excellent tips on spotting problems on oil-fired heating equipment. Booklet.)

InspectAPedia ^TM Home & Site Map - Building Inspection, Diagnosis, & Repair, Environmental Inspection & Testing - Research Website

The Mold Information Center: What to Do About Mold in Buildings, When and How to Inspect for Mold, Clean Up Mold, or Avoid Mold Problems

Home Inspection Construction Consulting Services & advice for home buyers

Contact Daniel Friedman for website content suggestions or for fee-paid consulting

	Enter your search termsSubmit search form
	Search This Website - InspectAPedia.com