Water pump randomly runs for short bursts
Greetings all, I've had two campers in my life and the first one I had was pretty rough and had lots of issues. One was that the water pump would randomly run for a second or so, which I didn't have...
Forum Discussion
TheLostBoy wrote:JimK-NY wrote:
No the pump can run even if all the faucets are off. One cause could be a slight leak. I would check the pump first. Slight leaks can occur with older pumps. Temperature changes can also cause the pump to run. If you turn off the hot water, pressure will slowly drop and the pump will cycle periodically to maintain the pressure. Changes in temperature can also do this even if the HW tank has not been heated. Temps dropping during the night can be enough to trigger the pump.
If the RV is not in use, it is easy to check for leaks. Pressurize the system and turn off the pump. If ambient temps are roughly constant, pressure should hold for at least a day or two and the pump will not run when turned back on.
What I'm afraid of is that it could be a leak inside the walls that I can't see. I don't have any water showing up anywhere that I can see (not around the pump either).
How do I measure the pressure in my lines?
You don't need to measure the pressure but rather make sure the system maintains pressure. Open a faucet slightly. The pump will go on and then off. As soon as the pump turns off, shut the faucet. Return hours or a day later. Turn on the pump. It should not run at all. This method is only valid if the temps withint the system are constant. That includes the HW tank. You need to make sure that the HW has been off for a day or so. I can perform this test over a period of a couple of several days if ambient temps are relatively constant. If the temp drops the pump will turn on to compensate for the lower pressure in the system due to the lower temp.
Most pumps will turn on if there is even a very small leak. So this is a very sensitive test providing ambient temps are consistent. It is pretty common for temps to drop at night and increase during the day. As long as the temp swings are fairly consistent you can still perform this test. Check the next day at the same time you started the test.
The chances of a leak somewhere in the walls are very minimal. Most of the runs are continuous without any joints. If the pex has been damaged, it is likely the leak will be very noticeable and the pump will run every few minutes or even more often.
