Fairford water pump

This problem has come on quite suddenly.  I have a full water tank and water emerges from taps at good pressure but pump runs and runs and won't cut out until I turn it off on the control panel.  Where should I start?

You need to adjust pressure switch, should be instructions  in handbook or there are videos on youtube

Alternatively, the boiler dump valve is open !
Keith

I'd tend to focus on the leak angle (as Keith suggests)  rather than immediately start adjusting pressure switch....it can be a b....er trying to get an equilibrium.
For instance, does it immediately start pumping as soon as you turn on the habitation electrics, or is it only after you open the taps for the first time.   Has this problem arisen since closed down for the winter.    Others on this forum have indicated in the past that it could be a voltage (or lack) problem....are you on hook up or just on leisure battery.

Good luck

PS >.I'm assuming it is pressure sensitive rather than electrically activated from the individual taps

Thanks for your suggestions.  Don't think it can be a leak because I can still briefly get water out of the taps a couple of hours after turning the pump off.  Sometimes the pump will stop running if I turn the taps off and on very quickly - its like I've shocked the pressure valve into action.  Sometimes (but not very often) it works as it should.  All this leads me to think the valve itself is faulty and I might do best just to replace it - if I can get at it, it's well hidden away.

Bob before going to the expense of replacing the valve remove the 2 screws at the inlet side and clean the small one way valve.  If this has unfortunately been contaminated by grit or scale it will allow water leaking back to the tank to constantly cycle the pump.  It is a known issue and I have suffered this myself.  Its only a 15 min job to do. Less likely as you still have some residual pressure in the system after pump has been switched off for some time but costs nothing to check.
      It could well be just adjustment required as Paul mold suggests and surely a small adjustment of the easily accessible knob on top of the valve, only  a little either way is easier and cheaper than just going out and replacing the valve. By the way a new valve would still need this adjustment so worth trying on the old valve first.

Adjust the pressure switch our fairford needs one setting for when on hook up and one when not. The switch is under the rear seat with the seat belts fitted near the side of the van.

Hi Bob,had same problem at first.Cured by setting up pump on 12v first using the pressure switch.I got the leisure battery down to 12.4v by turning on TV and set switch to give 5 to 10 secs overrun.On EHU the voltage is much higher and you will probably find the pump turns off with almost no overrun.Pump speed and hence pressure is very voltage sensitive,so set it to the lowest you use.Good luck.

Thanks for your various suggestions.  Will try them all.

Bob