Water pump runs.... and runs....and runs

[tobysdad]

Hi, all.
I have had the MH for six months, used it alot, and haven't had a plumbing problem until now. This past weekend we were boondocking, and whenever we left the (Shurflow) pump switch on, the pump would run about once per minute for about one second. I left it on for a couple of hours, and looked everywhere to try and find a leak with no luck. I do not have a plumbing diagram for it. The rig does not have a valve to switch from city water to fresh water tank, so I assume both sources are plumbed into the system with a one-way valve on each line.

Is it possible that the one-way valve (assuming I have one) from the fresh water tank is going bad, allowing pressure to slowly leak back into the tank, and kicking on the pump?

Oh, there actually was another plumbing issue I had. Seemed to me that the hot water heater took a long time to shut off. And then the water was lukewarm. Well, this weekend while I was looking for a water leak, I was checking out the heater really for the first time. The bypass valve was fully open, as was the cold water in and hot water out valves. Didn't have time to test it, but I'm pretty sure that closing that valve will make an improvement in the performance. But I'm thinking it has nothing to do with the pump problem.

Any suggestions would be appreciated.

Thanks,
Tobysdad

[Dave78Chief]

If you do not have a water leak (Don't forget the toilet), then it has to be the check valve in the water pump itself. The check valve in the pump itself is the one way valve you asked about. Shurflow does make repair parts for their pumps. Just need to know the pump model number
Parts Diagrams: SHURFLO Repair Parts Parts Diagrams

Dave

[tobysdad]

Thanks, Dave.
I'm sure it's not the toilet. I completely dried off the area where the water comes into the toilet, and would have seen moisture there after my test. I think it has to be either the check valve you mention, or a leak in a scary place, like inside the walls or something. I am assuming that my system is somewhat like the one I found at the top of this web page:
Water, Water, Everywhere!

except it has the check valve on the freshwater tank side integrated into the pump.

Thanks for the link.

[frankdamp]

The water is going somewhere!

[Billieg]

Check the back pressure valve in the city water inlet. Mine was bad and would allow air into the system..

[Chuck 1935]

If you have a city fill valve, for when you are hooked up to city water, that says fill and the valve is in that position it will cause the pump to keep running.

[RVJeeper]

I'd put money on your problem being the check valve. I do have a similar problem though when I forget to turn off the outdoor shower. If I leave the water on to the shower head and only turn off the shower head itself it drips just enough to make the pump cycle every now and then.

[Max Hubrich]

tobysdad,

If you have a 5700 (5.7) Shurflow, there is a phillips head screw in the center, bottom, of the pump. Turn this slightly to adjust the pressure on the switch. Turn it one way or the other, slightly, till it stops cycling.
It worked for me-

Customer service at Shurflow told me to do this.

[phays]

One last test you can do to see if it is the check valves in the pump leaking is to top off your fresh water tank, hook up to city water and see if your fresh water tank overflows. If it does, and you haven't left the water fill valve partially open, the only way water can get back into the fresh water tank is to flow back through the pump indicating pump check valve problems.