Water pump cutting in every 30 seconds or so

[Andrew_374564758]

Right hopefully someone can help. I have a 1965 Car Cruiser Caravan fitted with a water heater and microswitch tap system and a plug in (on the body side)submersible water pump which i think is a whale. The system was fitted by the previous owner. My problem is that when powered up every 30 seconds to 1 minute the water pump cuts in just for a split second. This is even after i have run all taps through to clear any air and there are no leaks anywhere on the system.

From online research I've come up with a few ideas, possibly the battery isn't giving full voltage - as yet i have only tried with the old battery the caravan came with?, a bad connection on the plug in water pump connectors?, a faulty microswitch? I also wondered if fitting a one way valve would stop water running back out the the system, or does the pump/ plug in connector have this in already - and if so could this be faulty? Any ideas anyone before i start dissmantling anything? Cheers, Andy

 

[raccoon]

Hi andrew, It sounds to me like there might be a water leak somewhere on the system. This will reduce the presure of the water in the pipes then the pump will try to send water through. Its the same when you turn on your taps and the presure drops and the pump kicks in.

This is if you have a presure switch fitted to the system and not the microswitch on the taps. So have a good look around to see if any water is lying about near to any joints. I have found that the joint where the pipes fit onto the taps is a good area for that problem but it can happen anywahere on the circuit.

Hope this helps you.

 

[TD42]

I have had this intermittant fault,& it was a faulty O ring in the plug in section of the whale pump.Try lubricating it with olive oil

mine is a pressurised system though,if yours is a micro switch system it will not be the fault

 

[Andrew_374564758]

Thanks for the suggestions, the system is definately a whale. Have had a good look today. There are microswitches on the taps and a built in microswitch in the unit mounted through the side of the van that the pump plugs into. I have replaced the rubber O ring seal as was perished and tried the olive oil suggestion but still no success. Pump presurises the system ok and then stops, however as soon as a tap is opened the pump starts as you would expect, then stops and keeps coming on every few seconds, until unplugged outside and refitted. Simply turning the power feed off, and then on, doesnt stop it clicking away coming on every few seconds. If you pressurise the system, then pull out the plug in pump a tiny dribble of water does leak back out through the water inlet bit of the socket - could this be the problem, or maybe the microswitch? Any ideas gratefully recieved before i go buy a new unit to try. Cheers, Andy

 

[ProfJohnL]

Hello Andrew,

This sounds as though there is a leak somewhere, and as you cant see it it suggests it is is probably a leaky none return valve.

Now the fact that the pump cuts in by its self points to a discrepancy with your description. You say it has micro-switched taps but that is at odds with the description of the pump tuning on and off by its self. Micro switches can fail, but they either fail open circuit (the pump won't run) or closed circuit (the pump wont stop) intermittent but regular self activation is highly unlikely.

My suspicion is that the micro-switches may be there in the taps, but not connected to the pump. Instead it is almost certain that the caravan has been fitted with a pressure switch (usually located very close to where the water pipe enters the caravan)

For a pressure switched system to work, it needs a none return valve to prevent water running back to the barrel and to lock the high pressure water in the pipework.

The NRV is usually built into the pressure switch. These can fail and stop sealing properly allowing the high pressure side to leak back to the barrel. This usually results a the pump making quite regular burst of activity to replenish the pressure in the system. as the leak is inside the pipework, you don't see any water drips anywhere.

 

[Chris_374413356]

Andrew, one of the reasons could be a not fully charged battery, basically, the voltage appears to be OK and the pump starts when it is called for. When the pump starts this causes the voltage to drop, thus stopping the pump.

When the pump stops the battery voltage after a few seconds recovers and the pump starts again, etc. etc.

 

[ProfJohnL]

Andrew, one of the reasons could be a not fully charged battery, basically, the voltage appears to be OK and the pump starts when it is called for. When the pump starts this causes the voltage to drop, thus stopping the pump.

When the pump stops the battery voltage after a few seconds recovers and the pump starts again, etc. etc.

Hello Chris,

I don't think that is Andrew's problem. If the battery were not adequately charged, the pump would not have enough power to raise the pressure in the pipework enough to cause the pressure switch to turn off, so the pump just keeps running. If the pump actually turns off, there must be enough power in the battery to raise the pressure.

 

[gary]

It would seem to me this is a pressure switched system, I once had a problem like this on a whale inlet and it turned out to be the non-return valve allowing water back into the aquaroll.

In this case the valve was behind a plate in the inlet housing outside where the pump plugs in, removing the plate exposed the mushroom shaped valve and one edge had turned under allowing it to leak.

Simply flicked the edge out so it sat flat and it worked perfectly, but, apparently it had been like that since new....and it was now a 15yr old van?!

 

[ProfJohnL]

The fault Gary reports may not have been like it from new. There is a common problem with the Carver Cascade, where the cold water inlet has a non return valve built in. If this is not fully drained during winter storage, any water left lying in the valve may freeze, and as the ice forms and expands it dislodges the O ring seal causing it to wedge in the set of the valve.

This results in poor hot water flow, and hot water finding its way back into the cold water pipes. The same form of valve is used in the crystal water inlet fitting, and some other fitting found in some caravans.

 

[xtrailman]

Andrew

You need to establish which control system you have, having the micro switches fitted to the taps does not always mean that the taps are in use.

In my experience all the tap micro switches fail open circuit, high resistance, so would not give the symptoms you describe, usually.

If your system is pressure switch controlled, adjustment of the pressure switch may cure your problem.

 

[Andrew_374564758]

Hi, thanks for everyones replies. I have since replaced the water inlet unit (whale) which has the built in presure switch. Those who suggested the system was presure, not tap micrositch contolled were correct, the wires on the taps were not actually connected! The water heater is a fairly recent propex malaga E, but even after 5 days of water being left in the system there is absolutely no sign of leaks - as the pump is cutting in so often i would expect a significant water leak should this be the problem. I have swopped the battery for the almost new one on my land rover and the problem is still there. I have tried ajusting the pressure switch in the new inlet unit in the recommended (in the instruction booklet) way as the problem was still evident with the factory setting, but still no luck! Should i keep trying adjusting this, or has anyone any other suggestions? Or should i simply give up and fit a flick rocker switch next to the sink to switch the water sytem electrics on when i want to use the tap? Or should i try a remote in line presure switch as was fitted in my lunar (could even fit a non return valve between it and water inlet to prevent water running back down into the aquaroll). Cheers, Andy

 

[ValA.]

Inside the inlet on the caravan there is a tiny little rubber non-return valve, (which looks a bit like a tiny umbrella about half an inch long). Our dealer sells them in packets of two for

 

[ValA.]

Sorry, I didn't read that you'd already replaced the inlet socket!

Our older caravan (1994 Sterling Europa) had a pressure altering switch under one of the front bed lockers, which if the pump 'alternated' had to be turned one way or the other and stopped the problem. Could your system have this? I can't honestly remember now what it looked like though, or how the adjustment was made. Do you have details of the previous owner to give him a ring and see if he had the same problems?