Well Foot Valve FAQs

Foot valve clog prevention
Foot valve falure causes pump damage?
Foot valve rating vs pump hp or psi

Can a foot valve clog in both directions?

Can a foot valve clog where water does not drain back down but it will also not pull up water? (Oct 19, 2016) Norm

Reply: Yes

Yes, Norm. Take a look at the foot valve photos in FOOT VALVES - the home page for this topic.

Mud, debris, in the well can clog the foot valve intake openings. Usually you'd see that as a reduced inflow well before the valve clogs totally.

Foot Valve Sediment Clogging Prevention FAQs

What's the proper gap from the well bottom to the foot valve?

Is there any rule for maintaining the gap from the floor for Foot valve in well/sump and if so how much(? Oct 28, 2014) Anonymous

Reply:

The distance from foot valve to well bottom may vary depending on the well type but typically it's two to five feet.

Unable to prime the pump traced to a sedimentclogged foot valve by UK reader.

Being new to private wells *never seen or heard of a private well in the UK its all city water* ive been on a steep learning curve, some of problems I've had and the fixes maybe of help to others.

Someone left the garden hose on twice. Both times the well appeared to run out of water. The second time I couldn't reprime the pump.

We replaced the pump and well pipes only to find the foot valve had a bit of goop that stopped it up fully. A new foot valve was put in but the pump still wouldn't prime.

We found out the foot valve was sitting in the sediment. [The well piping end with foot valve was placed too low in the well bore - Ed.]

So if you replace the well pipes make sure they are exacltly the same length.

Our new well pipe was just a foot longer than the original.

Separately, I also had a pump short-cycle problem that despite an OK pressure check on the water tank led us to find that the internal tank bladder was shot. I thought that maybe the lighting strikes could damage the tank bladder so that may be worth a check.

Also I had two well pumps, both same horsepower, but one was far worse than the other at pulling water.

[Editor's note: even at the same horsepower, that's just the pump's motor strength. If the pump's acutal impeller, the assemblhy that moves water, is clogged or damaged the pump will move less or even no water.]

I hope this helps some of you out there - (Mar 1, 2013) N in the U.K.

Reply:

Thanks N.

If you know how far down the bottom of a well pipe or foot valve has been placed, it's easy to measure the current depth of the well bore down to the top of sediment or mud.

See WELL DEPTH, HOW TO MEASURE 

That will tell us if the foot valve is too close to the well bottom.

On occasion it's useful to clean the settled sediment or mud out of the bottom of a well;

There are also procedures and devices to suck silt and debris from a well bottom. If that doesn't suffice it might also be necessary to raise the foot valve a couple of feet higher from the well bottom.

See details at WELL CLEANING PROCEDURES

Can a foot valve prevent a pump from turning on?

Would a foot valve on a above ground pump cause the well pump not to kick on ? On 2019-08-17 by Anonymous

Explanation by (mod) -

That seems unlikely, Anon, but actually not quite impossible.

For example, if a foot valve is clogged or leaks so that the pump loses prime or can't draw water from the water source (well, lake, etc), then IF the pump continues to run "dry" the pump can overheat OR if there is a pump protection switch installed, that switch could trip, leaving the pump off.

See WATER PUMP PROTECTION SWITCH 

Will a bad foot valve cause a loss in pressure?

Will a bad foot valve cause a loss in pressure? 3 Nov 2016 Leanne said:

Reply: Not directly

Not likely, Leanne; the pressure in a water system is determined by the water pump, though indeed a leak in well piping, water running in a building, or poor water flow into the well can reduce the water flow rate - a condition some people refer to as water "pressure".

(Pressure, more accurately, is measured in psi while flow rate is measured in volume of water delivered per minute or gpm or lpm)

Indirectly and more subtle, if a foot valve causes repeated loss of pump prime, the pump or its impeller assembly could be damaged so over time recurrent foot valve problems and lost well prime could damage the pump and cause some loss in water pressure.

Foot Valve PSI Ratings vs Pump Power and Pressure?

Can I use a 400 psi foot valve on a 1 1/2 hp pump with a discharge release of 75 psi? On 2019-07-25 by Barbara

by (mod) - maximum psi ratings on foot valves in wells

Yes Barbara.

The psi rating on a foot valve is the maximum pressure that the valve can withstand without leaking.

But depending on the depth of your well you may need additional check valves. You don't give your well depth so here is an excerpt from the article above that explains in more detail:

In general Flomatic valves are pressure rated 400 psi or 920 feet of water pressure. This does not mean that a valve can be set at a well depth of 920 feet.

To alleviate and reduce the hydraulic shocks in the riser pipe it is recommended that a check valve be installed every 200 feet in the riser pipe.

- source: "Foot Valves Installation Instructions", Flomatic Corporation, 15 Pruyn's Island, Glens Falls NY 12801, Website: flomatic.com, - retrieved 2/10/14, original source: www.flomatic.com/assets/pdf_files/oem/16048.pdf

Available at InspectApedia at FOOT VALVE SPECIFICATIONS Flomatic [PDF]

How do we protect a foot valve from clogging by zebra mussels?

What can be used to protect a foot valve that's attached to a water pipe in a lake to keep out zebra mussels?

I have the foot valve tied on top of a cement block to keep it off the lake bottom.

Also, I have a 1/2 hp jet pump. Is it possible to connect some type of filter to the water pipe just before the pump to prevent sand, small debris, etc.from entering the pump? On 2019-06-16 by Nancy

Solution by (mod) -

You can fabricate a cage using chicken wire or similar screen with openings small enough to discourage mussels, but the cage still needs to be quite large so that even ask the muscles stick that sells on to it it will not immediately be blocked.

Does the length of horizontal piping mean I need an additional check valve besides the foot valve

I am installing a shallow well pump in my garage and pulling water from an underground spring. The set up requires a horizontal suction pipe from well to pump with 6' of rise total. Approx 80' of horizontal run. Do I need a special horizontal foot valve for this or will a normal foot valve work? On 2018-09-29 by NP

Answer by (mod) -

No, NP.

On a well pipe between well and pump, the horizontal run won't add much to the risk of loss of prime; a foot valve at the bottom of your shallow well pickup will be just fine.

In contrast, on much deeper wells additional check valves at intervals on the horizontal lift pipe in the well or even on steep hillside well pipign installations are often needed to prevent loss of prime.