Water running back, pump starting intermitten

We have a 2019 Bourton, last trip out water was running back, pump coming on every 10-15 minutes to build pressure up to taps. Have cleaned tank out but its still doing it. Is there a one way valve in the pressure switch which we can dismantal and clean out or replace and am I right in thinking the pressure switch is under the seat.

I had a similar problem on our Broadway. It wasn't doing it as often as yours but if the pump was switched off overnight water was draining out of the hot water system. There is a non return valve in the whale pressure switch which in our van is under the bunk near to the Truma drain valve. Whale have a video on their website showing how to clean the non return valve. It should be easy to do but the way the switch had been fitted didn't leave enough room to access the two screws. I had to disconnect the water pipes and remove the pressure switch. The valve was clean, I put it back and the problem remained. I fitted a new switch and the problem was solved. If your van is still under warranty, three years for Whale components you should be able to obtain a replacement. To buy one is £30 plus. They do sell a kit which includes the replacement rubber and some other bits which are about half that. If you had a leaking joint somewhere in the system the pump would run as you describe. I checked to see if there were any signs of leaks before
I checked the pressure switch.

Thanks for your reply, very very helpful

Just to add that the video is on you tube not the Whale website but it is a Whale video.

David

I had a similar issue to yours from the outset which seemingly couldn't be rectified and is the main reason I now have a Shurflo.  In your case it may be the Whale NRV/pressure switch and something stuck in the NRV causing it to allow pressurised water to flow backwards through it.  If the Whale NRV is leaking in this way, it should only affect the cold water as water pressurised in the hot water tank should be held there by a second Truma NRV fitted between the cold water inflow and Truma drop valve.  But I found that sometimes this NRV failed to hold the hot water (after I had turned the pump off) which overnight dumped back through the Whale NRV into the freshwater tank, which shouldn't happen.  After endless experimentation I discovered that part of the reason for the Whale submersible pump continually coming back on for maybe 5 seconds at a time was a reduction in water pressure in the hot tank as the water in it cooled.  I think the same happens with the Shurflo but to a much lesser extent and when it happens it is barely noticeable.

Mine was affecting the hot tap.

Thanks everyone for your replies, today the pressure switch was taken out and another bought to be fixed in place tomorrow morning. Also as my other half has always wanted to replace the pump with a Surflo one was purchased along with connecters and pipe and will be fitted over the winter months.