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How Much Air to Add to a Water Pressure Tank WaterAPedia © Enter your search terms Submit search form   Search This Website - InspectAPedia.com

• How to add the correct amount of air back to a water pressure tank to stop short cycling and get good water pressure and flow
• How to diagnose & correct short cycling "on-off" of the building water pump
• Well pump & water tank diagnosis & repair procedures

This article describes how air should be added to a building water tank in a building water supply system where a private well is the water source. Readers of this document should also see Water pump and pressure tank repair diagnosis & cost an specific case which offers an example of diagnosis of loss of water pressure, loss of water, and analyzes the actual repair cost. The illustration at page top is courtesy of Carson Dunlop, Inc. in Toronto.

HOW MUCH AIR TO ADD - How Much Air is needed in the water pressure tank?

These comments only apply to methods 1 and 2 above. Method 3 is so simple you just don't care about this question.

• You want enough air in the tank that the pump stops short-cycling. Don't worry, you can't put in too much air - as long as there is a pressure relief valve on the tank bottom you cannot damage the tank by trying to put in excessive air pressure.
• If the tank does not have a pressure relief valve intended for water tanks installed on the tank bottom or nearby to protect the tank from over pressure you should have one installed. Especially with systems using a submersible pump capable of pumping to high pressure, this is an important safety device.
• If you are uncertain about whether or not the tank is protected from overpressure, you are safe pumping it to 30 psi before re-starting the pump.
• If you have put more air into the pressure tank than necessary, the excess air will simply squirt out of various faucets the next time you run water and then the problem will go away.

If you look at an older pressure tank you can usually see a darker or even rusted color at the bottom portion of the tank. The top edge of this colored area marks the normal air-water boundary in the tank. (Condensation on the water-filled part of the tank causes this corrosion or darkening.) In this photograph the black mold and debris stains on the lower portion of the water tank probably show the usual levels at which water has been maintained in the tank. So if you've pumped air into the tank and later you see that the top of the area of tank covered by condensation is about where this line is, you're in business. If you see condensation occurring 2 or 3 inches from the top of the tank you need to add more air. I used to put in enough air to give a minimum of 30 seconds of water running before the pump came on but this number varies widely depending on pump power and on how fast an individual fixture runs. So ignore air quantity advice based on time except to watch out for real short-cycling as described earlier.

Water Tank Maintenance & Repair Chapter Index

Use links just below or at the left of each of the pages at our website to navigate this document or to view other topics at this website. Green links show where you are in our document or website.

PLUMBING TOPICS
OIL TANKS
SEPTIC SYSTEMS
WATER PRESSURE REPAIR GUIDE & COSTS
WATER PRESSURE LOSS DIAGNOSIS GUIDE
  WATER PUMP PRESSURE CONTROL ADJUSTMENT
  WATER PUMP PRESSURE CONTROL REPAIR
WATER PUMPS & TANKS & WELLS
WATER PUMP CONTROLS & SWITCHES
PUMP TYPES & LIFE EXPECTANCY
WATER PUMP & TANK SAFETY
WATER SUPPLY & DRAIN PIPING
WATER TANK TYPES: WATER, OIL, EXPANSION, ALL
WATER TANK LIFE EXPECTANCY
WATER TANK REPAIRS
WATER TANK AIR, HOW TO ADD
  WATER TANK AIR VOLUME CONTROLS
  WATER TANK AIR ADD AT AIR VALVE
  WATER TANK AIR IN BY DRAINING
  HOW MUCH AIR TO ADD
  AIR HOW OFTEN TO ADD
WATER TANK REPLACEMENT
WATER TANK PRESSURE CALCULATIONS
WATER TANK SIZE & VOLUME
WATER TANKS HOW THEY WORK
WATER TESTING
WELLS CISTERNS & SPRINGS
WELL LIFE EXPECTANCY

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• Water pump and pressure tank repair diagnosis & cost an specific case offers an example of diagnosis of loss of water pressure, loss of water, and analyzes the actual repair cost
• Water pressure tank failures & water pump short cycling diagnosis and repair
• Cheating on water tests: Testing Water for Real Estate Transactions - make sure your water test is valid
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• Lead Contamination in Drinking Water: Testing & Correction - Advice (This Article)
• Lead Testing & Correcting Contamination from Lead Water Supply Lines/Entry Mains - Lead Pipe Problems/Advice
• Water testing for Pesticides: comprehensive and pesticides-example parameters
• Water Testing: background comments on classes of water contaminants, & links to home buyer advice about water testing, drinking water, water supply
• When and How to Shock or Chlorinate a Well - Procedure for Shocking a Well to (temporarily or maybe longer) "Correct" Bacterial Contamination
• Water Requirements, Home & Outdoor Living
• Typical Water Tests & Fees this water test fee schedule applies when testing is combined with other onsite building inspection services
• Drinking Water testing, contamination, correction - all topics
• General water testing and corrective measure advice: contact your local health department.

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