Do ALL Rv's do this? If I leave the water pump on..

ChopperBill wrote:
Funny, have had 5 rv's 4 of them new. Every one of them would cycle for a second every few hours. No external leaks, the pump check valve just looses a little pressure and the pump cycles. No big deal unless you make it one.

I agree ,but it seems some do not, they think we have some kind of problem that needs addressing. Seems every RV I have owned did this, had a very short cycle now ,and then. Never worried about it, and have never seen a problem.

Funny, have had 5 rv's 4 of them new. Every one of them would cycle for a second every few hours. No external leaks, the pump check valve just looses a little pressure and the pump cycles. No big deal unless you make it one.

Folks, RV's are not Space Shuttles. The water system is a very simple system with a lot of plastic tubing and fittings. It is designed to be "water" tight, but it is certainly not "air" tight. RV water pumps work off demand. Open a faucet, pressure in the system goes down, pump turns on in an attempt to rebuild pressure. Close the faucet, pressure is allowed to rebuild and the pump turns off.

Occasionally, system pressure bleeds down, even with no demand on the system, and the pump will momentarily come on and bring pressure back up again. Your pump should not run frequently or for a lot of time with no demand on the system, but an occasional blip for a second or so every couple hours is not unreasonable or out of spec.

If you don't like the pump "burping" the system from time to time, turn the pump switch off when you are not actively using onboard water. This is a good practice to get into anyway. If a plumbing fitting were to fail or a run of pex developed a crack, you could fill your motorhome with the contents of your potable water tank in a matter of minutes.

I have a small burrup with mine every so often, so I just don't worry about it, as I've not encountered any leaks. For prophylactic reasons, I flip the water pump off when I leave the TT just for my peace of mind, or the rare times I'm on FHU, I'll turn water off at the faucet (provided I remember to do so.)

If I were planning to keep my trailer indefinitely, I'd probably add an accumulator tank or replace the water pump with a variable speed model.

dave54 wrote:
If you cannot find a drip, then it is probably a check valve. They all become old eventually, and not seat completely. A minor annoyance and on most water systems a bit of a job to replace the valve. Most RVers just live with it rather than try to fix it.

This is where I am with my TT. Going on season 11 with it. Last summer for the first time since we've owned it I noticed on rare occasions the water pump would "burrrp" momentarily - I went over all the plumbing, couldn't find anything wrong, especially nothing leaking. So now we just live with it.

It is probably the check valve in the pump. I have had that problem in two different RV's.


Options:
1. grin it and bear it
2. turn the pump off and on as needed
3. fix it.

Currently I am using option 1 and 2.

:h
It's a spring loaded check valve. You can wiggle it all you want and nothing will blow. If it's just slightly off center it will leak just a bit and cause the pump to bump.

Air in the piping will cause the intermittent pumping. Our problem was the diaphragm in the pump.

Turtle n Peeps wrote:
I would venture to guess 70% of the time it will be the city water inlet check valve not seating. Go to it and push it around a bit.

That is a really good way to blow the check valve seal out of place! Ask me how I know! Turn the pump off first and relieve the pressure first. Or run city water in the valve/connection. Chris

I do not know about what is normal or not but I do know that my fresh water demand pump was installed in 2003 and has done as you described only once.

I checked everything and found it was the outside shower valve was not completely off and was trickling ever so slightly. No water noticeable on the outside of the little compartment but there was a little puddle inside. I turned the valve handle and it has never happened again... knock on wood!