“Check Valve” causing water pump to not stop?

[VCToyhauler]

Does anyone know if we have a “check valve”, separate from the water pump, that can go out and cause the pump to not stop?

Or if there is any pressure adjustment available on a typical wfco water pump?
Or any pressure switch that needs replacing?
Or are these integrated into the pump, and it not stopping means having to replace the pump, even though it’s still working?

I’m not seeing any leaks anywhere, yet the pump won’t stop!
Battery is tops. Tank is full...

[ATCguy]

Originally Posted by VCToyhauler

Does anyone know if we have a “check valve”, separate from the water pump, that can go out and cause the pump to not stop?

Or if there is any pressure adjustment available on a typical wfco water pump?
Or any pressure switch that needs replacing?
Or are these integrated into the pump, and it not stopping means having to replace the pump, even though it’s still working?

I’m not seeing any leaks anywhere, yet the pump won’t stop!
Battery is tops. Tank is full...

Ok, I'm no plumber, so I can't answer any of your questions. But, what I have done is blown up a few sections of that schematic that I posted in the other thread... so maybe you (and others) can see the components that are there, and possibly figure it out:

The first blowup is the "Materials List"... which shows 2 check valves in the system. (Items 140 & 122)

The 2nd is the layout at the water intake, which shows check valve "122" I've circled it in red.. and also circled where it directs you to an inset view of the water pump components.

The 3rd is a blowup of that inset... with arrows pointing to the pump, and the check valve "140".

By the way... if you right-click on any of these photos, you can save the images to your computer, and they'll show up larger & with better quality than looking at them here on the forum.

Hopefully this will help you out.

[dsol]

Sometimes there can be a leak in the plumbing somewhere which will cause the pump to run constantly too.

If you turn the pump off the tank should stay pressurized enough to get a little water from a faucet when you open a valve before it stops, but if you have a leak you might lose pressure so fast with the pump off that you can’t get any water at all when you try it.

[ewarnerusa]

Is the pump filling your hot water tank? When that tank is empty, the pump can run as it tries to fill it (usually a 6 gallon tank).

I've also heard of scenarios where the outside shower taps are open and it allows circulation to occur which may allow the pump to keep running, although I can't quite picture that scenario in my head right now.

[VCToyhauler]

Thanks ATCGuy! You’ve always got the map - and quickly! Nothing looks visibly wrong, but I let the pump run for a while, and there is a bit of water around it. I did find mention of a pressure adjustment allen but now leaning towards a new pump. The old was wfco. New probably shurflo?

[VCToyhauler]

Thanks... I gave it plenty of time... the hot should be full.. i ran it for a while, and am seeing slow dripping from the pump. I think the pump itself is leaking. Ordered a shurflo 4008.

[ewarnerusa]

Originally Posted by VCToyhauler

Thanks... I gave it plenty of time... the hot should be full.. i ran it for a while, and am seeing slow dripping from the pump. I think the pump itself is leaking. Ordered a shurflo 4008.

I didn't even know WFCO made pumps, I was going to chime in that WFCO is the converter brand.

I posted in your other thread about possibly a black tank flush that is on?

[sundancer 87]

Those pumps will rattle the housing screws loose.

[VCToyhauler]

Thanks Warner - checked all the other valves and everything else looks ok and as it should be.. but I noticed a slow dripping from the pump, so I’m assuming it’s dying and not able to fully pressurize..

[The Cramblersons]

Originally Posted by ATCguy

Ok, I'm no plumber, so I can't answer any of your questions. But, what I have done is blown up a few sections of that schematic that I posted in the other thread... so maybe you (and others) can see the components that are there, and possibly figure it out:

The first blowup is the "Materials List"... which shows 2 check valves in the system. (Items 140 & 122)

The 2nd is the layout at the water intake, which shows check valve "122" I've circled it in red.. and also circled where it directs you to an inset view of the water pump components.

The 3rd is a blowup of that inset... with arrows pointing to the pump, and the check valve "140".

By the way... if you right-click on any of these photos, you can save the images to your computer, and they'll show up larger & with better quality than looking at them here on the forum.

Hopefully this will help you out.

Attachment 6745

Attachment 6746

Attachment 6747

Check Valve 140 looks like it is merely keeping water from flowing back into the hot water heater when the bypass is engaged. So when there is water flowing from the water heater and the system is "pressurized" that check valve isn't doing anything.
Check valve 122 is really a sanitary backflow preventer required to keep water from the trailer from going back into the city water system. Just like a sprinkler system backflow preventer on your home.
I don't see how either of those would cause the water pump to run continually. And when the city water is on, the water pump isn't required anyway.
This is a real head scratcher! For me anyway.

[persistent]

I am not an expert pump person. However, I am always willing to share my misconceptions.

I think the pump has a built in back flow preventer. One expert told me this and said it was not called a check valve.

The pump rotor seals can be worn.
The pressure switch can be defective.
The pressure switch is adjustable on some models.

Pumps can be disassembled and repaired. I have one in my garage that has a cracked pump chamber. I have a problem throwing things out. I could order a replacement pump chamber and fix it. It may take a while to figure out the part numbers and find a source so, it just sits there staring at me.

If your plumbing does not have a leak and the fresh tank fill valve is properly set, you may want to just get a new one. (You may or may not have a fresh tank fill valve.)

I wish you good luck and happy trails ahead!