Whale water pressure switch - possible fault??

[TheTravelMan]

Hi, I recently posted a problem we had with very poor water pressure on a Bailey Pageant Majestic 1988 model. This problem was on all taps both hot and cold. There was a new pump fitted last year which has not solved the problem. i've looked at all pipe work to check for kinks and faults - all seems OK! Whilst checking all pipe work and point of entry into caravan i noticed a whale pressure switch of which the water travels from pump thru filter then into this pressure switch before splitting to either hot or cold system. This switch also has a knob on the top which can be turned, I assume to alter your pressure, so I tryed turning in both directions, however there is no difference in water pressure. I have also noticed the pump every so often whilst all taps are closed keeps firing up for a few seconds as if it is pressurising up! Is this normal or does it sound as if the Pressure switch could be faulty? I still need to flush water pipes for descaling and to renew water filter but wanted to rule out the pressure switch 1st. Any advice or comments appreciated, Many Thanks, Andrew.

 

[cris_408518]

I think this is the same Switch we had in our Bailey. It has to be turned until a clicking sound is heard to set it.

If so it has a small screw top that is about 3/4' across with a bumpy side so you can grip it. It has a rubber diaphragm that fails and renders it useless. Last one I purchased cost about 14 euros in Eire.

Try http://www.whalepumps.com/documents/brochure/Caravan_Brochure_2005.pdf

Page 4 - Inline pressure Switch (WU7207)

 

[JTQ]

Andrew,

As you say "the pump every so often whilst all taps are closed keeps firing up" means that the Whale pressure switch is at least functioning as it should. This is normal as despite all being closed there is likely to be a very minor leak in the supply non return valve from the pump causing the system pressure to drop and the switch to work both to start and then stop the pump again.

It may however be set to do this at too low a level, the adjusting screw is there to alter this but ultimately you will not get more pressure than your pump can develop. So it could be a pump problem. If there is an immediate lost of acceptable pressure the instant you open a tap down to an unacceptable level then that would indicate some restriction to the flow; the prime target for causing that would be the inlet supply non return valve, the one mentioned earlier. Hope this gives you enough info to explore what is wrong.

 

[JTQ]

I have just checked on Cris's referenced document and note that the inlet supply non return vale is an integral part of the Whale Pressure switch. So if that "surge then decay" characteristic I mentioned is exhibited then you need to look there.

 

[cris_408518]

ps . I would add that we used the caravan connected to the mains quite a few times before we had to use the tank and aquaroll. The water worked OK ish via the mains. But next to useless on the tanks.

On a 1988 van I would expect the diaphragm to be well past its sell by date and would replace the switch as if it has not failed it is likeley to at any time.