Water Pump Runs Too Frequently

Vibe101 · 10-06-2022, 11:57 AM

When boondocking the electric water pump operates too frequently.

I have checked every water appliance inside and outside and no leaks and no apparent leaks from under the trailer.

The water heater has been purged and no air comes out of faucets

Could the pressure on/off switch have an internal leak?

Does anybody have any trouble shooting advice before I replace the pump motor?

Thanks

markb422 · 10-06-2022, 12:16 PM

Did you get the problem resolved?

**Mr. Dan** · 10-06-2022, 01:24 PM

Quote:

Originally Posted by markb422

Did you get the problem resolved?

The problem was only posted 19 minutes when you asked if he solved the problem. What am I missing?

markb422 · 10-06-2022, 03:54 PM

I must have missed the post time.

Reverse_snowbird · 10-06-2022, 04:15 PM

My knowledge of water pumps is non existent.
Does anyone have any suggestions?

paverdave · 10-06-2022, 04:26 PM

A quick search of Forestriverforums https://www.forestriverforums.com/fo...sly-197743.htm
hope this helps......

frozen · 10-07-2022, 08:09 PM

I'm reluctant to say this because it seems a little weird, but on our current and previous RVs, when the pump begins short-cycling (running too often) I've shut off the pump, then removed the anode rod from the water heater to drain a couple quarts, replaced the anode, re-started the pump. Short cycling ends and the pump runs far less often. It seems as though a head of air in the water heater serves as a pressure tank.

TitanMike · 10-07-2022, 08:18 PM

Short cycling can also be caused by obstructions in the output line(s).

If an factory installed filter is in the line it might have a clogged filter. Not necessarily enough to be really noticeable but enough to slow the flow so the pump builds enough pressure to shut off even though a faucet is open.

Another common source of flow restriction is the aerator/screen at the faucet or shower head. Things to check.

Lastly, many, if not most, water pumps used today have a bypass feature which involves the setting of two pressure adjustments. It's possible that this adjustment is incorrect and needs attention. Find the make and model number of the pump and search the internet for a manual which will have the instructions. Of course there are also Youtube videos covering water pump adjustments of all makes.

Larry-NC · 10-07-2022, 08:28 PM

Also possible that the check valve (one-way valve) in the water pump is not seating properly. The pump builds up pressure in the plumbing and stops. Then the pressure causes water to seep backward into the fresh water tank. As soon as the pressure drops a little, the pump runs again. You never lose any water but it's annoying and runs the battery down.

There are a couple of options.

You could try letting the pump run and build up pressure. Then turn the pump off and bleed off the pressure by opening a faucet. Then close the faucet, turn on the pump, and repeat. This might clear out a small particle that was preventing the check (one-way) valve from fully closing.
You can take the pump apart and clean the check valve.
You can simply buy another check valve and mount it externally on the pump output side.

Richy R · 10-08-2022, 08:12 AM

Quote:

Originally Posted by frozen

It seems as though a head of air in the water heater serves as a pressure tank.

When that symptom occurs on my rig I use a similar principle.
Shut off the H2o pump, open the galley sink hot water faucet handle, that relieves the water pressure, leave faucet open, then open cold water low point drain, drain H2o for a period of 30 seconds or so, close low H2o drain plug, close galley hot H2o faucet, re-energize pump to pressurize system, open galley H2o faucet to re-fill H2o heater and reestablish air pocket in H2o heater. Turn off faucet once steady flow of H2o heater H2o is dispensed from faucet. H2o pump short cycling eliminated.

Hope this helps.
Richard in Milwaukee

**KyDan** · 10-08-2022, 08:22 AM

We're all guessing here so my guess is they mean the pump runs often when no water is being used. I say this because they said "I have checked every water appliance inside and outside and no leaks and no apparent leaks from under the trailer."
IF this is what they mean, it's probably debris in the pump check valve or a bad check valve. I guess it's possible to change the check valve but I'm not sure you can get one. In my pump the check valve is integral with the pump diaphragms. Once upon a time I searched the internet looking for one to fit mine and wound up just buying a new pump.

NevadaMiniLite · 10-08-2022, 09:43 AM

I had the same problem on my 19 Mini Lite 2109S. Turned out to be something really simple - bad low point drain caps letting air into the system. Replaced them and problem solved. Good luck.

jeff64 · 10-08-2022, 11:13 AM

Quote:

Originally Posted by KyDan

We're all guessing here so my guess is they mean the pump runs often when no water is being used. I say this because they said "I have checked every water appliance inside and outside and no leaks and no apparent leaks from under the trailer."
IF this is what they mean, it's probably debris in the pump check valve or a bad check valve. I guess it's possible to change the check valve but I'm not sure you can get one. In my pump the check valve is integral with the pump diaphragms. Once upon a time I searched the internet looking for one to fit mine and wound up just buying a new pump.

Likely debris in pump head just like in aerators on faucets

Vibe101 · 10-08-2022, 11:51 AM

Hi All,

Just got back to internet.

THANKS for your suggestions.

The problem is that when no water is flowing from any faucet (or from a leak) the water pump will cycle on for a short period of time then shut off and repeat this cycle every 2 minutes even though no water is being used.

All of the water appliances were carefully checked and no water is coming out in the sinks or outdoor shower.

The panel behind the water service ports was removed and carefully inspected and no leaks.

I thought that perhaps it would have been a small leak somewhere under the rig and it was small enough to not be noticed however there is not water accumulating on top of the belly liner.

Another possibility would be that the one way check valve that separates the city water input from the water lines inside the trailer had debris in it causing a very small leak and if so the water pump would be filling up that water pipe very slowly and because that pipe has a fair amount of volume to fill up it would not be noticeable.

Also considered that if the leak was super small then the water would evaporate under the rig and therefore not be noticeable so I just now connected up the city water connection and am waiting to see if any water puddles down below.

I would hate to have to buy a new pump just because there is a bit of debris in the check valve...perhaps it can be disassembled and cleaned...Grrr

I might try the air gap at the top of the water heater trick instead.

Vibe101 · 10-08-2022, 11:53 AM

>A quick search of Forestriverforums https://www.forestriverforums.com/fo...sly-197743.htm

PaverDave,

The link you sent did not work. What term did you search for?

Vibe101 · 10-08-2022, 12:14 PM

Now that I am in civilization with internet I downloaded the Shurflo 4008 pump manual and it talks about an adjustment for the bypass feature.

The first step is that I am going to perform filter cleaning and the sanitizing procedure and if the issue is a check valve leak within the bypass feature then hopefully the bleach will dislodge the crud.

Then if the problem persists I might try to fiddle with the pressure screws. Any advice on the pressure screws?

Here is the water pump manual if someone needs it

THANKS

paverdave · 10-09-2022, 04:12 PM

Quote:

Originally Posted by Vibe101

>A quick search of Forestriverforums https://www.forestriverforums.com/fo...sly-197743.htm

PaverDave,

The link you sent did not work. What term did you search for?

"Water Pump Runs" in search on this forum

flyflotrtim · 10-09-2022, 04:31 PM

If you have room for the install, you might consider adding a check valve rather than attempting to reair yours. Inexpensive and easy. https://www.amazon.com/Quickun-Inlin...s%2C140&sr=8-9

InTheSticks · 10-13-2022, 06:22 PM

I cant speak for your pump, but when it has happened to us it has been a small piece of debris in the pump head diaphragm. I normally will just get a new kit and pull that one apart and if I find something in there (small pebble/sand/junk) I will put it back together, if not I will replace the guts.
Again that is what works for us in our camper... 27HFS.

dowend · 10-13-2022, 08:08 PM

I dont know for sure that it is the pump which is letting the water pressure drop and causing the pump to run, but it might be.
My key piece of advice is that you can buy a pump reconditioning kit for about $20 instead of replacing the entire pump for $200. Google and amazon are your friends. Its a super easy job.

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