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bad99ram's avatar
bad99ram
Explorer
Jun 21, 2013

Water Pump

Cycles every 5 min when faucets are turned off to keep up pressure. Checked all fittings starting at the pump to faucets ect. All are tight. I have screen on pump and that is clean. Rebuild or just replace?
  • It can be a couple of things.

    The fresh water fill valve (from shore water) can leak by water (mine does) and cause the pump to cycle.

    Also check for a leaking toilet fill valve. If the water is dripping into the toilet, you might not find the bowl full.

    I guess you already checked the outside shower, and are not getting puddles under the RV?

    If you are at home, and can leave it plugged in and on for say 12 hours, if the tank level is not dropping after say 10 hours, you will pretty much know it must be the shore water to fresh water tank valve leaking by. Changing out mine will be a pain, so I have not done it yet, just turn on the pump as needed.

    Good luck!
  • IF there are no leaks it may be the check valve in the pump. Pumps have a check valve that holds pressure after the pump shuts off and it may be leaking back into the fresh water tank. You can rebuild the pump or install a after market check valve in the water line downstream of the pump.
  • Also make sure that there isn't any air in the lines as that can cause it too.
    If there aren't any leaks, including the toilet, then it is just probably a bad check valve or pressure sensor, either one can be replaced.
  • Pump cycling......
    Possibles (as mentioned)
    'City water' connection check valve leaking.....water drips from connection down side of rig
    Pump internal check valve leaking..back thru pump to fresh water tank
    Leak at fittings........hot/cold water lines
    Toilet water valve leaking......dripping into toilet bowl
    Shower(s) turned off at 'handle' and slight dripping
    OR
    Water heater pressure relief valve leaking....dripping from PRV (re-establish air pocket)