Seeking troubleshooting ideas

[waywardwind]

Periodically, our water pump will cycle. I have searched for sources of small water leaks, but have not found any evidence of a leak. This may occur several times during the night, or not at all. I have checked the outside shower, bays below the fresh water tank, under sinks, ice maker. The pump lives under our bed, so it can wake us when it cycles at nite. We have turned the pump off when we retire for the nite, and in the AM, when we turn it on again, it may or may not cycle. I'm open to any fresh ideas, like for example, is there a check valve in the pump? Flaky pressure switch? TIA Perhaps it is the switch?

Adjusting a Shurflo pump pressure switch.

1. You don't need to take the pump out of the camper – or take the pressure switch apart!
2. Look for the allen screw on the top of the pressure switch.
3. Turning clockwise will result in a more sensitive switch (more likely to cycle)

 

[SeilerBird]

Try tightening up all the hose connections as tight as you can.

 

[Lou Schneider]

Water contracting as it cools down inside the water heater while it is off can make the pump cycle once or twice. This drove me crazy until I figured it out. Leave your water heater on overnight as a test and see if the pump still cycles.

 

[Rene T]

Do you have to open a valve to fill the fresh water tank when hooked up to shore power? If you do, that valve may be open just a touch or that valve could be leaking by just a little. Try cycling the valve several times and see if that works.

 

[Gary RV_Wizard]

The pump itself may have a tiny internal leak, allowing pressure to bleed back through its inlet hose. Adding a check valve to the inlet hose (near the pump) would cure that without replacing the entire pump.

The tank-fill diverter valve that Rene mentioned is another fairly common source of tiny leaks. A few drips per hour can be enough to cause occasional pump cycling.

 

[Robert K]

Probably old seals letting the pressure bleed off. My pump did that till I replaced it . It does not do it anymore

My pump was 20 years old so figured it was time to replace

 

[Great Horned Owl]

The pump has an internal rubber diaphragm and several internal rubber seals. These can become brittle with age, and begin to leak. You won't see the leak, because it is contained within the pump.

You could replace the pump, but there are rebuild kits available for most pumps. They are not difficult to install.

Joel