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Bayley's avatar
Bayley
Explorer
Jun 03, 2017

Water pump recycles

Is it common for a water pump to cycle on and off once in awhile on it's own? I have check all water connections and faucets for leaks and no sign of water leaking anywhere. It only happens once in a great while and it comes on for about a second or less.
Thanks for the help!!
  • Your water pump has a check valve inside that is suppose to prevent water from backflowing into your freshwater tank when on the city water hookup, and also hold pressure to all the faucets once pressure has been obtained while using the pump on 12 volts without city water. This could be the problem.

    If you have no leaks present anywhere, the other possibility is that it's sucking air from the suction line that goes to the freshwater either through the line or the inlet screen on the inlet side of the pump. If you find nothing there, then it would be likely the backflow valve on the pump has some trash in it and is allowing a little water to backflow and once the pressure drops the pump will cycle shortly to regain the predetermined pressure.

    In some cases you can take the pump head apart and clean it out. Sometime just cycling the pump off and on with the faucet numerous times will make the trash clear itself.
  • I had a pump on a previous FW that did the same thing, after a number of years of service, it would tend to loose pressure and have to cycle to rebuild. I just replaced it, kept it for a spare, and still use it sometimes, to pump from a container, into my fresh tank.

    Jerry
  • Every RV I've owned or been around has done that. Even a faucet that drips once every five minutes will bleed enough pressure to make the pump 'blip' once in a while. If it's annoying, just turn it off until you need water, then turn it on.
  • Even a very tiny water leak will result in your water pump cycling - if you have an outside shower make sure you inspect that closely.
  • Typical 15# differential start/stop pressure settings

    If shut off is set for 45# then pressure has to drop to 30# for pressure switch to close

    If shut off is set for 55# then pressure has to drop to 40# for pressure switch to close

    Long duration in between pump short cycling is not unusual.
    Could be a very small leak at a fitting, hose crimp, T&P Relief valve weeping, water cooling down in water heater, pump internal check valve, city water connection check valve etc.