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Hi,

We have got a 1988 swift challenger, our first caravan, today on testing the van the whale pump was constantly running when all taps turned off. I have been told that a microswitch may be the problem. I have read on other forums about pressure systems, what is the difference between pressure and microswitch?? How do you know which you have?? If it is microswitch how do I get to them and how do I test them??

Sorry for so many questions but I am totally confused and want to get it sorted to get away at easter.

Many many thanks

Lisa

In a micro switch system each tap contains a tiny switch. Turn the tap on and the water pumps runs, turn the tap off and the pump stops.There is a micro switch under every tap, both hot and cold so there could be six, so more to go wrong.

You know if its a microswitch by a slight click when you turn the tap on and off.Micro switches were used on older vans say pre 1995 (ish).

If a tap won't operate the pump turn another tap on slightly. This should switch the pump on and water will come out of the first tap and most likely points to a faulty micro switch or wiring fault. The microswitch is at the bottom of the tap. You will need to remove the tap and may be best replacing the whole tap.

A pressure switched system is simpler than a micro switched one as it only has one pressure switch which switches the pump. The taps simply turn the water flow on or off or up or down. When a tap is turned on, the pressure switch simply detects that the pressure in the pipes has reduced and runs the pump. Turn the tap off and the pressure switch detects the rise in pressure and stops the pump. If there is a slight leak in the pipes the pump will run occasionally to maintain the pressure even if the tap is not open.

The pressure switch works best if there is a surge damper as well as it smooths out the pumping. You can adjust the flow from the tap from very slow to fast. You need to adjust the pressure switch correctly. To do this turn on a cold tap and close it slowly until the water comes out at a slow trickle. Then adjust the pressure switch until it can be heard constantly switching on and off.

Personally I would go with a pressure switch and surge damper. You can convert to this from a micro switch system quite easily.

Had another look at the caravan and pump today. I can't see any know for adjusting pressure anywhere on the pump and when I turn on taps they have a click so I am guessing microswitches.

My next problem is acessing the switches. My kitchen tap has the fridge underneath and my basin and shower taps are in a sealed unit.

My kitchen and basin taps have 4 screws holding them into unit, if I unscrew will the tap lift up to get access to microswitch??? and if it's my shower taps any ideas on how to access them???

I have taken photos as I aren't very technical, infact not at all but I can't upload them

Thanks

If it is a faulty microswitch, the pump will still run if another tap is operated. Don't forget you may have 6 microswitches but any one of them should operate the pump. It's unlikely that every switch has failed.

If the pump doesn't run at all it's more likely to be one of these:

• the pump
• the fuse
• the pump isolation switch on the control panel
• the socket the pump plugs into.

I would try and check each of these things. See if the pump works if you cannect it direct to the battery. If not it's the pump. If it does see if there is power at the socket it plugs into etc. 

You may get at the kitchen taps if you remove one of the grilles behind the fridge. They have a turn screw at each end holding them in.

The problem is that the pump won't shut off when all taps are off rather then not coming on.

I will try to get access through the fridge vent, thank you

It may still be that you have a pressure switch. A lot of older vans would have been changed to one but still leave the microswitches on the taps. It is easier than trying to change a faulty switch.

The pressure switch will be located in the water pipe after it has entered the van, most likely be in the bed box behind the pump inlet. It's quite likely that the pressure switch simply needs adjusting.

Sorry to be a pain but I just really don't get the microswitch at all.

I have keller taps in the kitchen and shower and comet on the basin. The basin handles lift off and I presume the white plastic with wires is the microswitch. What I don't understand is how to test it or remove it, I am probably being really stupid.

I had a challenger with the same problem, so I purchased a new pressure switch (nearly 30 quid) never needed it, turns out to be loose wire, so never even took it out of bag. so if you need a new one, I have one for sale...