Fresh water tank filling by itself

[bobsbbq]

We recently upgraded to a new to us 2002 Sunny Brook Mobile scout. I emptied the fresh water tank about 1 week ago using the pump. Today I noticed water coming out the overflow on the fresh water fill compartment. We stay on city water all the time, I have a 40 psi regulator as we'll. the only thing I can imagine is the water is back flowing through the pump in to the fresh tank, and slowly. I would have thought there would be a one way valve to prevent this? Has anyone had a similar issue? I do have a valve next to the pump I can shut off, but I would have to remember to open it every time or you can burn the pump up.

[Beartoo]

Check your weater valve positions,I had the same thing happen this spring.

[Cummins12V98]

I would contact ShurFlow. They may send you a new pump.

[lynndiwagon]

Yep, check valve in pump is leaking. Just went through this. Go to Camping World and buy 1/2" check valve. Go to Home Depot or Lowes and buy the flexible 1/2" to 1/2" flexible line. Unscrew the 1/2" connection from the pump outlet and screw on one end of the flexible line, screw the other end of the flexible line to the check valve (with arrow pointing away from the pump) then screw the line that you took off of the pump to the other end of the check valve. Confusing? This will work.

[Luke_Porter]

Do you have a tank fill valve on your city water?

[Old-Biscuit]

Valve next to pump...........?
Typically there are no shut off valves for the pump. Water Heater yes..pump no.
And pump can run dry without harm..they are diaphragm pumps and only move about 1/8"

You probably have a Shurflo Classic (model 2008) as it is the one mostly used by OEM. That pump has been phased out.....parts still available (Check valve 94-237-00..about $12)

You could also just install a 1/2" in-line check valve in pump suction or discharge line. Shurflo has one......#340-001

[rockintom]

Check valve in the water pump. If it's an older pump, replace it. If not, replace the check valve.....most RV parts store keep them in stock. Valve about $10. Easy repair.

[bobsbbq]

This was one of the things I looked for, but did not find any plumbing to support this mod. The other thing is if there was a mod to fill from city it would fill the tank in 15-20 min max. Not a week. Thanks for the suggestion, maybe it is just a bad pump.

[Ron_Nielson]

Water should not back feed thru the pump. This is likely your problem. You could rebuild the pump head or just get a new pump. OR the previous owner may have created a system to fill the water tank from the city water lines. This is a popular mod. See if your unit has the valving that would allow water to come from the city lines into the fresh water tank, bypassing the water pump.