caravan pump wont turn off

[westie1961]

hi all, I have had about 4 caravans over the years and never realy had any problems until i bought our latest van.

its a 2004 abbey, i looked around ht evan before handing over any cash and it all seemed fine,

however on my first trip out i noticed that as soon as the pump was switched on it would continue to run even with the taps turned off,

on our return home i disconnected the wires to the taps and this has made no difference, it appears to be a micro switch controlled system.

Is there a micro switch inside the water heater, it is a 10 litre system.

Because the water has no where to go it comes back out of the inlet on the outside of the caravan.

if i open the taps inside the caravan, although water comes out of the taps water also still gushes out of the inlet on the side of the caravan.
its as thought the pump is going too quickly.

Is there a micro switch inside the water heater, it is a 10 litre system.

 

[RogerL]

Many caravans use a pressure switch, not the old micro-switches in the tap - but the micro-switches will still be there! The pressure switch is usually located just after the inlet connector - a Whale pressure switch can be adjusted - if it's adjusted wrongly the pump will run continuously.

On the other hand, the inlet connector may have developed a leak which means it doesn't create enough pressure to cut out.

 

[westie1961]

hi, there definitely isnt a pressure reducer, i know what they look like as another van we had used that method of controlling the pump.

 

[ProfJohnL]

hi, there definitely isnt a pressure reducer, i know what they look like as another van we had used that method of controlling the pump.

Hello westie1961,

Its not a 'pressure reducer' it would be a' pressure switch'.

We obviously don't know for sure how you pump is controlled, it will either be a pressure switch or micro switches in each tap. but which ever way, something is either maladjusted or broken.

With the micro switched taps as soon as ANY tap is even slightly opened the micro switch can close and turn the pump on, so first double check ALL the taps are turned off.

If the pump still runs, then one or more micro switches have failed. Depending on the design of the tap the micro switches may be replaceable. Otherwise its change the tap. Don't forget the shower taps,sometimes a trigger operated shower rose has been fitted - to save water, but with micro switched taps it wont control the pump.

If it is switched taps, then you have to disconnect the wires for each tap until you find the one thats causing the problem.

If its still a mystery, then you have to trace the power wires backward from the pump looking for anything that might be causing a problem - watch for wires pinched by furniture or stapled etc

If that all becomes to much, then you could always add pressure switch and disconnect all the taps wires.

 

[Damian]

Quote " Is there a micro switch inside the water heater, it is a 10 litre system"

No there is NOT

 

[westie1961]

hi, have tried disconnecting the taps power supply at each tap and it made no difference, the pump keeps running.

i think fitting a pressure switch is probably the best answer, i wasnt sure if that would work.

its a fixed bed abbey from around 2004

 

[woodsieboy]

Have you tried another pump on your system?

 

[westie1961]

hi, thats something i havent tried yet, to be honest i have bought a spare one and i am waiting for it to be delivered but i get the feeling that its not as simple as that.

i put a volt meter on the pump connectors and they are showing as live as soon as the pump is turned on inside the van. thats with all of the taps disconnected

looking at the thickness of the wires to the taps i assume there must be some sort of a voltage relay or the tap wires would melt as they are so thin.

i am going to try and trace the wires back from the pump to check for any obvious problems and if that doesnt solve the problem I will get a pressure switch as suggested above and link that with a relay to the pump and switch.

 

[Gafferbill]

Because the water has no where to go it comes back out of the inlet on the outside of the caravan.

..........you do not tell us what type of pump you have? Submersible or on board?
From your statement above I am guessing you have a submersible.
Have you checked that there are O rings present on the fitment where the pump plugs into the outside of the caravan.
Your description suggests they are leaking or not present and that because of this the pump is failing to reach sufficient pressure to activate the pressure switch and is therefore not turning off!

Edit...........Just noticed that Roger L has said the same in an earlier post :huh:

 

[westie1961]

hi there, o ring is present, and i have tried adding ptfe tape and this has made no diference i have also replaced the o ring

there is sufficient pressure to get water to all of the taps,
it is a submersible

 

[Gafferbill]

........even with the pump running the water should not be able to come out of the inlet or near it.

I would look for the source of this leak and stop it before looking elsewhere for a reason why the pump keeps running.

 

[westie1961]

hi bill, i dont agree with your comment, if the pump is running and the taps are closed the water has to go somewhere or damage a component.

how many litres of water does your pump move per min?

 

[RogerL]

hi bill, i dont agree with your comment, if the pump is running and the taps are closed the water has to go somewhere or damage a component.

No it doesn't - it simply builds up to the maximum pressure the pump can achieve, which isn't actually that high, and then it just runs without moving any water.

 

[Gafferbill]

RogerL has explained the science and it is likely it does keeps running because you have that inlet leak

 

[westie1961]

hi, so you are saying that a system controlled by microswitches within the tap will continue to pump when the microswitch is disconnected.?

 

[johnandrew70]

Have you checked the pressure switch on the back of the inlet socket if your system has one and made sure the drain down tap is closed.
Our system is on board and as soon as i power the system the pump will run until the water heater is full, Also the pump will run when the aquaroll is empty. Of course if you have a submersible pump then disregard this.

 

[ProfJohnL]

The OP first needs to find out how his pump should be controlled. Is it micro-switches in the taps or is it a pressure switch, then we can start analyse and offer more focused advice.

 

[colin-yorkshire]

hi, so you are saying that a system controlled by microswitches within the tap will continue to pump when the microswitch is disconnected.?

Absolutely yes!!!!!!!
why!!!!! well because of how the system works the pump gets it power from the pump switch down the positive wire, which in turn is returned to earth via the negative wire,
now the pump switch only supplies a direct positive feed to the pump this is cut when the switch is operated to off.
when the switch is on the pump receives power but will not run as it has no return to earth, this is where the micro switches come in as they are on the negative return,
if the pump can find an alternative route to earth it will continue to run wether the micros are connected or not and each switch on the system is independant. somewhere on the system there is a short back to earth. but not in the literal sense of a short (ie sparking) because the pump itself acts as a buffer and the positive wire that feeds the pump is not directly shorting, merely doing what it is designed to do and run the pump.via a return. (that is any return).

however this is only applicable if the system is not the pressurised type but the mechanical switched (micro) type
make sure you know which type of system you have, and then trace the circuit with a meter.

ps, if you pull all the wires from all the micros cold and hot and the pump still runs it should be a easy matter to find where in the system short is!!

 

[WoodlandsCamper]

Because the water has no where to go it comes back out of the inlet on the outside of the caravan.

You obviously have a major leak to the outside and therefore the water system cannot get up to pressure and therefore does not turn the pump off. Possible causes are:
1. cracked filter housing (I have had this twice on an older van, caused by screwing the filter in too tight)
2. faulty seal on filter or inlet connection
3. filter not screwed in correctly.

 

[ProfJohnL]

Some of the answers on this thread must be so confusing to the OP..

He has been told that if all the micro switch wires are disconnected the pump will still run!! I know Colin went on with explanation of how it must then be short circuit somewhere, but the logic is a bit backwards.

I think it would have made more logical sense to put it this way:

If all the micro switches are disconnected the pump should not run. If it does then somewhere there is a short circuit in the wiring to the pump.

He has been told that if there is a water leak the pump will continue to run. What is missing here is the point this problem can only occur if the system is pressure switch controlled.

It all comes back to understanding which control system his caravan has is it switched taps or is it pressure switched? only then can we start to provide more focused answers

 

[Gafferbill]

Some of the answers on this thread must be so confusing to the OP.........
..........It all comes back to understanding which control system his caravan has is it switched taps or is it pressure switched? only then can we start to provide more focused answers

..........sorry Prof but the OP should not be confused.

Logic tells us that a water leak on the outside of the caravan is not normal and I have told the OP earlier that he needs to stop this leak which he thought was caused by the pump creating too much pressure.

Any caravan engineer would correct this defect first before looking for another reason for the submersible pump to keep running.

The OP also told us he had disconnected the micro switches which made no difference to the problem...but on a purely micro switched system this should have stopped the pump.
Abbey may have fitted micro switches and wiring but still used a pressure switch.........that is the case in my Swift.

 

[ProfJohnL]

Hello Gaffer,

We're still no further on, I agree, It was not unknown for manufactures to use a stock tap (already preloaded with the micro-switches) but to use a pressure switch, as you say, But they did not install the carcase wiring to the taps as it was not necessary. The OP has already stated he has disconnected some of the micro-switches, which suggests to me the carcase wiring is present pointing to a switched tap system.

Assuming the caravan is Second Hand It is of course quite possible a previous owner to have added a pressure switch to replace the micro-switches functions in the taps. - but this second guessing.

The external leak should of course be addressed, but that will only affect the pump switching if the system is controlled by a pressure switch.

The annoying thing is If we were able to see the caravan very quickly we could confirm how the pump is supposed to be controlled, and found the offending parts!

Its so frustrating not to have accurate information.

 

[RogerL]

It seems to have two faults:-

- as the microswitches appear to have been connected originally, it's a microswitched system, not a pressure-switched one - so if the microswitches have all been disconnected but the pump still runs, there's an electrical short, as suggested upthread.

- as water leaks externally when the pump is running, it has a leak - possibly inside the external connector.