Join Date: Sep 2013
Location: South Devon
My Motorhome: Bessacarr E725
Thanked 162 Times in 141 Posts
If the hunting stops when you turn off the valve from the tank, it means that the pressurised part of the system is leaking back through the pump.
It may be that you can dismantle the pump and clean the valves, or they could be worn meaning replacement is necessary.
Do you have a filter on the inlet side of the pump? If not, it may be very small particles have prevented the valves sealing properly and it will simply mean a clean.
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