Question? Just ask us!
Free Encyclopedia of Building & Environmental Inspection, Testing, Diagnosis, Repair
InspectAPedia ® Home
WATER PUMPS, TANKS, TESTS, WELLS, REPAIRS
WATER CONSERVATION MEASURES
WATER CONTAMINANT LEVELS
WATER FILTERS, HOME USE
WATER HAMMER NOISE DIAGNOSE & CURE
WATER ODORS, CAUSE CURE
WATER PUMP REPAIR GUIDE
WATER PRESSURE LOSS DIAGNOSIS & REPAIR
WATER PUMP SHORT CYCLING
WATER SOFTENERS & CONDITIONERS
WATER TANK REPAIR PROCEDURES
WATER TANK: USES, TROUBLESHOOTING
WATER TESTS, CONTAMINANTS, TREATMENT
WATER TREATMENT EQUIPMENT CHOICES
WELLS CISTERNS & SPRINGS
WELL CHLORINATION & DISINFECTION
WELL FLOW RATE
WELL WATER PRESSURE DIAGNOSIS
WELL YIELD IMPROVEMENT
WINTERIZE A BUILDING
This article describes How to restore lost air in a building water pressure tank using a garden hose and gravity in a building water supply system where a private well is the water source. This procedure is used as a simple means to correct water pump short cycling when the cause is a water-logged water tank.
Green links show where you are. © Copyright 2014 InspectApedia.com, All Rights Reserved.
USE GRAVITY - Method 3: How to Use Gravity to drain the water pressure tank and then to let air into it
Here we explain a most basic way to get the proper air charge back into the water pressure tank and thus to stop well pump short cycling. This article also provides a second procedure for cases in which the water pressure tank is already working normally but wants fine-tuning of its air pressure - at Alternative procedure for water tank air pressure
Rocking the water pressure tank: (Gently) If the water-containing rubber bladder in a "captive air" water tank is defective (it can become stuck to itself and remain collapsed), the result can be a rapid on-off short cycling of the water pump.
We test water pressure tanks to see if they're empty or nearly empty of water by seeing if we can rock or move the tank. If the tank is heavy with water it does not move easily. Be careful not to jiggle and break a pipe! Bladder type or captive-air water pressure tanks and their repairs are described just above and in more detail at WATER TANK TYPES.
Readers of this document should also see WATER PUMP REPAIR GUIDE 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.
The photograph shows a typical water tank with controls located near the tank bottom. Clicking on this photo shows an enlargement of the blue-handled drain valve that might be used to drain all of the water out of this tank in the "gravity procedure" we discuss below. In this particular photograph, you can see lots of water system components that can be identified:
[Click to enlarge any image]
On your water supply system these components may not all be present and they may at slightly different locations.
Here is a step by step method to add air to a water tank to stop short cycling of the pump.
You'll need a garden hose. That's about it, but read all of these instructions through before starting this project
The procedure just below is most suitable for a bladderless steel water pressure tank.
The tank drain will always be located at the bottom of the tank. Don't get mixed up with some higher faucet somewhere else or this method won't work. If there is a floor drain near the tank you can simply drain the tank to that drain, but watch out! Often these drains are clogged. Don't have a basement flood; have a garden hose handy to drain to outside if needed.
In this photo, the long handle marked "water" is the water shutoff between the water tank and the rest of the building. When this valve is at right angles to the direction of the water pipe, that shutoff is "off".
We leave it open (parallel to the pipe, as you see it here) for this procedure so that air can get into the tank from a nearby open faucet in the building. In this photo the round black handled valve marks the water tank drain to which you will attach a garden hose.
The small brass fitting to the right of the black drain valve is a pressure relief valve needed on any pressurized tank.
The water pressure gauge is also visible in the center of this photo as is the blue base of our water tank in the background. On your water system these components may be located differently.
Run the other end of the garden hose outside and to a location where the end of the hose will be lower than the tank drain. After all eventually we're going to be relying on gravity and water does not run uphill.
(Don't wiggle the tank all over the place or you might cause a pipe to leak.) Now water is barely running out of the hose because no air can get into the tank. It's like holding a full soda bottle upside down - air has to work to get in past the water gurgling out. In this case air would have to bubble all the way in up through the garden hose. We'll meet our maker before this will ever happen.
So here are some ways to get air into the tank, arranged in order of preference:
You can't make a mistake since any excess air will be automatically purged later when you run various fixtures.
Warning about loss of pump prime: in a few instances, draining the water tank can also drain water out of the pump itself - if the pump is inside the building. Some (indoor) water pumps, if drained dry, won't be able to lift water back into the system.
Such pumps need to be re-primed. This is a use for that water we told you to run and set aside before beginning your project. Pumps that need to be primed will have a fitting (or a simple pipe plug) atop the water pump housing itself that is opened, and into which pump priming water is poured until this chamber is filled - usually a quart is about enough to refill the pump. This is never a problem with submersible (in-the-well) water pumps.
This alternative method for fine-tuning the air pressure setting in a water pressure tank was suggested by reader Mark Caruso. CONTACT
Watch out: The water tank air pressure adjustment described below is only suitable if your water tank is already working normally and if there is no evidence of a waterlogged pressure tank, significant water pressure tank air loss, or
Note that adjusting the water tank air pressure is not a substitute for adjusting the water tank pressure control switch discussed
The pressure control switch sets the cut in and cut out pressures of the water supply system. The proper volume of air in the pressure tank avoids short cycling of the water pump as we discuss beginning
Mr. Caruso's alternate idea for fine-tuning a non-waterlogged water pressure tank air charge includes these four simple steps:
Bladderless Steel Water Pressure Tanks can lose their air charge over time and may need air added by any of several methods described beginning
Bladder type or "captive air" water tanks do not normally need to have makeup air added, and water pressure or short cycling problems with bladder-type water tanks are usually traced to a failure of the bladder itself - a component that may be replaceable.
Continue reading at WATER TANK AIR HOW MUCH TO ADD or select a topic from the More Reading links shown below.
Suggested citation for this web page
Green link shows where you are in this article series.
Frequently Asked Questions (FAQs)
Question: hissing sound coming from my well
There is a hissing sound coming from my well, and the submersible pump is brand new, and the power is turned off to the well pump. What is causing this? - Candace Hanscom 11/25/11
Candace, hissing may be air being vented inside the well from a snifter valve. We explain the snifter valve at WATER TANK AIR VOLUME CONTROLS - or you can search InspectAPedia for "How to Find & Repair the Water Tank Air Volume Control Device" to read more about that device.
Question: my bladderless water tank becomes waterlogged quickly after draining
I have a bladderless tank which rapidly becomes waterlogged after draining. I drain it completely using a hose (the tank is placed very high) - that is, until no more water comes out (and I have opened house faucets to let air in). Immediately after this, the short-cycling is much better (pump running 15 seconds not 1 second) but within a day short cycling starts again. I suspect I have water trapped in the tank but I'm reluctant to remove the top plug from the tank in case I damage things. No Schrader on the tank. Paul Adams 5/14/12
Questions & answers on the procedure for adding air to a water pressure tank by draining the tank using a garden hose.
Use the "Click to Show or Hide FAQs" link just above to see recently-posted questions, comments, replies, try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.
Search the InspectApedia website
HTML Comment Box is loading comments...
Technical Reviewers & References