Water pump problem

[tommybrown78]

Hi.

Hopefully someone can help me and save me a few quid (which I don't have much of after buying my van). I have just bought a elddis typhoon ex300 4 berth caravan. Used it for the first time this weekend and the water pump would not shut off. I have check the taps micro switches and when the tap is opened the pump light on light comes on and goes off when switch off. Problem is the pump stays on and is filling the water tank and beyond and now I have a leak somewhere. I do not have a pressure switch so have been told that the system works solely on micro switches. Any help would be much appreciated. One of the local repairers has said he would fit a pressure system for £140 to hopefully fix the problem after we have found the leak of course. Any help would be much appreciated as all the micro switches appear to be working as they should. Cheers.

Tom

 

[rosies]

Hello Tommy ,
For the pump to be operating then it must be receiving 12v ,( obviously ) this 12v must be controlled by the taps micro switches or the previous owners ad hoc wiring ??? . First check ALL ( including hot water ) tap micro switches by removing the output wire to pump on each individual switch , if the pump stops then its that micro switch to fault . If not then you have some other power crossed wire within the circuit . The confusing item is you say , 1) you have a leak , 2) the pump is filling the TANK ?
!) Naturally you need to locate and fix any leak as the small flow from the pump will be trying to replenish the water lost in the circuit as soon as you turn on the tap operating the pump micro switch .
2) The word tank raises strange possibilities , boiler , then yes , but tank would suggest inboard water tank were the pump would be situated , my thoughts are that you have a outside water pump placed into a aquaroll type container . if not then this TANK could be an accumulator therefore you would have a pressure switch within your water pump circuit that could be the problem operating the pump.
Basically you have to find where the power source 12v is coming from by process of elimination .
Steve.

 

[colin-yorkshire]

Hello Tommy ,
For the pump to be operating then it must be receiving 12v ,( obviously ) this 12v must be controlled by the taps micro switches or the previous owners ad hoc wiring ??? . First check ALL ( including hot water ) tap micro switches by removing the output wire to pump on each individual switch , if the pump stops then its that micro switch to fault . If not then you have some other power crossed wire within the circuit . The confusing item is you say , 1) you have a leak , 2) the pump is filling the TANK ?
!) Naturally you need to locate and fix any leak as the small flow from the pump will be trying to replenish the water lost in the circuit as soon as you turn on the tap operating the pump micro switch .
2) The word tank raises strange possibilities , boiler , then yes , but tank would suggest inboard water tank were the pump would be situated , my thoughts are that you have a outside water pump placed into a aquaroll type container . if not then this TANK could be an accumulator therefore you would have a pressure switch within your water pump circuit that could be the problem operating the pump.
Basically you have to find where the power source 12v is coming from by process of elimination .
Steve.

hi, just an observation but if the van in question has indeed got a micro switched system (as opposed to a pressure system) then it will spring a leak if the pump continues to run with the taps turned off, as there is no where to release the pressure. once the fault (that is causing the pump to run) is found the leak will disappear on it's own.

 

[RogerL]

hi, just an observation but if the van in question has indeed got a micro switched system (as opposed to a pressure system) then it will spring a leak if the pump continues to run with the taps turned off, as there is no where to release the pressure. once the fault (that is causing the pump to run) is found the leak will disappear on it's own.

Caravan submersible pumps are the centrifugal type, not positive displacement, so can only build the pressure up so far and then no further as the impeller just cavitates - the rating used in caravan applications is unlikely IMO to cause a leak by not switching off when it should, at least not in an otherwise sound system.

 

[tommybrown78]

Hi and thanks for your responses Colin and Steve. Sorry probably the way I described the system. It is all micro switches and the water tank is the boiler for hot water (new to this lol). A caravan repair place has offered to fit a pressure switch into the system for £140 but would rather just fix the fault. Can the switches on the taps still fail on and ask for water even if the red light below the pump switch is off? Thanks. Tom

 

[Craigyoung]

Hi , I've got a baileys and my pump light was illuminating and running and slightley leaking but from where pump connects to van and running down the outside of van above my marker lights , I read it could off been a blocked filter but it ended up being two worn rubber washers where the pump slots in costing penny's and seconds to change , hope you get sorted .

 

[RogerL]

Hi , I've got a baileys and my pump light was illuminating and running and slightley leaking but from where pump connects to van and running down the outside of van above my marker lights , I read it could off been a blocked filter but it ended up being two worn rubber washers where the pump slots in costing penny's and seconds to change , hope you get sorted .

Those O-rings should be replaced every year and lubricated with silicone grease or vegetable product like margarine - but never with vaseline, any petroleum product or WD40.

 

[rosies]

Sorry to say Tommy but I'd certainly keep away from that so called caravan repair centre when it sounds like there is NO need for a inline pressure switch , Just try and find out were the power source for the pump is coming from , slow and easy wins the race . Steve .

 

[colin-yorkshire]

Can the switches on the taps still fail on and ask for water even if the red light below the pump switch is off? Thanks. Tom

hi Tom, yes it can.
if I may I will try and explain without too many technical confusions.

caravans have by enlarge two types of water systems,
1. microswitch
2. pressure.
in the micro switch type the electrics run in a series circuit, power from the pump switch goes directly to the pump down a positive wire the return or earth goes through each of the micro switches hot and cold to make a circuit. now the pump will only run when a tap is turned on, there is no residual pressure in the system, (apart from the small amount in the hot tank when it is on due to the expansion of the air gap at the top of the boiler) this is lost when the a hot tap is activated as the boiler is then refilled with cold from the pump.
if the pump continues to run then the pressure will build up, and a leak can occur, from a joint (not normally) under pressure or simply because the hot tank overfills and runs out of the overflow (this should go through the floor near the tank) but could have a split or have been dislodged. while roger. is correct about a sound system it is supprising just how much a non pressurised system can leak if put under constant pressure through the pump not stopping.

now with the pressure system there are no micro switches connected except for the pressure switch. on this system the wire goes to the pump as before but the return is via a pressure switch now the pump continues to run until the water system reaches the pressure threshold set by the pressure switch, when a tap is turned on (any) the pressure drops and the pump starts this then continues to run (even with the tap now turned off) until the system pressure is restored, at this point the pump stops, however the pump will run at any time if the pressure drops.

but the problem "why does the pump continue to run when it should not" if you had the pressure system it is a simple case of the system is not pressurising properly this could be either a leak, a faulty or ill adjusted pressure switch or the water tub is empty.

on the micro switch system there is no pressure to regulate as it is a mechanically operated circuit via the switches so either one is faulty (on when it should be off) or there is a short in the system that enables the pump to find an alternative return and complete a circuit thus it continues to run.

the fitter that recommended changing to a pressure system via fitting a pressure switch is not offering a repair, just another way to cure the problem without fixing it!!! as the fault would still be there just circumvented by altering the wiring. in my view he would also have to make sure the system was pressure tight and could account for the high cost involved.
in my view the only way to solve the problem is to find the fault and keep the system the way that it is.check all the switches and the wiring that goes to them somewhere you will find something amiss a crossed connection or a short.
hope this helps sorry it was so long but hey we all have head scratching moments.

 

[rosies]

Put in a far better way than I could have Colin