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 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
Well Foot Valves: this article describes the foot valve used on well piping for water well Pumps & Water Wells: we explain what a foot valve is, how they work, why they are used, and how to diagnose troubles with this special in-well check valve found at the bottom of well piping in some wells. We provide advice about loss of well pump prime due to bad foot valves and what to do when things go wrong with the check valve.
Green links show where you are. © Copyright 2014 InspectApedia.com, All Rights Reserved.
An Explanation of Well Piping Foot Valves
Carson Dunlop's sketch (left) shows the main parts of a one-line jet pump well installation. Nearly all well pumping systems, one line jet pump, two line jet pump, or submersible well pump, require a foot valve installed at the bottom of the well piping.
A Well Piping Foot Valve is a one way or anti-siphon valve which is installed on the pick-up end of the water pipe near the bottom of the well.
Foot valves are also used on deep well installations to help protect against loss of prime in the well piping system.
Since you won't normally see the foot valve on well piping (it's down in the well) we have included a photograph of a well piping foot valve at the top of This article .
Watch out: without a working foot valve, a shallow well jet pump is likely to lose prime and will stop working properly, risking loss of water supply to the building and even damage to the pump itself.
As you may guess, a foot valve is basically a check valve combined with an inlet strainer (visible in our page top photograph). The strainer prevents picking up large debris that could clog or jam the foot valve in its open position (or that might damage the water pump itself).
The check valve is a one-way valve that lets water flow up from the well and into the well piping. The spring loaded check valve closes when the well pump stops pumping.
Closing the check valve prevents water in the well piping from falling backwards into the well when the pump has stopped running. We need this function to keep the well piping and water pump filled with water - otherwise the well pump may lose prime, leading to loss of water in the building.
If the well piping foot valve is leaky and water runs back into the well we increase the wear on the water pump as it has to run more often, and pretty soon
the water pump will lose its prime (water inside the pump mechanism) and it may be unable to retrieve any more water from the well whatsoever.
Foot Valve Clearance from Bottom shows that the well piping and foot valve are inserted into the well some distance from the very bottom of the well (inches to a few feet). We need this clearance to reduce the tendency of the well pump to pick up mud and debris from the bottom of the well.
Reader Question: do jet pumps come with a built in check valve or do I need a foot valve or both?
I have model pkg 1-54AP 2" single pipe jet kit for a sta-rite sld-l 3/4hp jet pump. Does the jet package come with a built-in check valve and if it does, do I need a foot valve? Thanks! - David
David take a look at the page top photo - if your kit didn't include something that looks like that, you don't yet have a foot valve.
Yes some jet pumps include a built-in check valve.
It's true that some jet pumps include a check valve in the nose of the pump; and it's also true that some experts recommend only using a single check valve. If your well is quite shallow, say less than 27 ft. you might get away without a foot valve. But if I were installing new equipment including piping into the well, I'd put in a foot valve - as the most reliable component, and because it's easy to do now and more trouble to add later.
Also see our discussion of the WELL PIPING TAIL PIECE that protects well pumps from damage in a low-flow poor recovery rate well.
If you are having trouble losing well prime and suspect a bad foot valve or check valve, also our article on above-ground CHECK VALVES, WATER SUPPLY, and see WELL PIPING LEAK DIAGNOSIS and Repeated Loss of Pump Prime and also WELL PUMP PRIMING PROCEDURE
Green link shows where you are in this article series.
Frequently Asked Questions (FAQs)
No FAQs have been posted for this page. Try the search box below or CONTACT US by email if you cannot find the answer you need at InspectApedia.
Try the search box just below or if you prefer, post a question or a comment in the Comments box below and we will respond promptly.
Search the InspectApedia website
HTML Comment Box is loading comments...
Technical Reviewers & References
Related Topics, found near the top of this page suggest articles closely related to this one.