Water Pump Problems?

[jwa]

Hi, we have an Elddis Xplore 556, which at a year old, has just had an annual service. We took it away to Longleat at experienced some strange goings on with our water pump?
It is making an odd clicking noise when we turn on the taps, which it never did before and this is repeated in the night for no apparent reason? No one is using the taps; it just comes on like a Tube Train starting up and wakes us up! After three days of checking, draining etc, we turned the pump off at night which is something we have never had to do in umpteen trips away.
Should I let the supplier know and take it back to them for inspection or is it something simple like an airlock? Why would it come on at night all by itself?
Thanks in advance for any ideas.
John A

 

[Rick1]

Hi John what type of system is it? Does it have a pressure switch normally located close to where the water pump is connected,has a sort of wheel nut on top, if so this may have been accidently moved, sometimes a drop in power can cause it to operate, need a bit more info on the type tho then can maybe help out more, mine had the same problem, but was caused by a seal failure in the pressure switch.

 

[Gagakev]

Hi John, seems like you have pump clatter, should be simple to remedy.
Adjust the pressure switch wheel inside the van normally just behind the inlet

Should look like this (click here)

Hope this helps

 

[jwa]

Hi, I think it is Truma, but that is the water heater, presume it is all the same system? Why would that come on at nigh by itself?

 

[jwa]

I'll look at the pump again tomorrow, would pump clatter cause it to come on at night too?

 

[ProfJohnL]

Hello JWA,

Most caravan manuafcaturers chose equipement to fit into their caravans from a range of different suppliers. It is not uncomon for the water heater to be made by an entirely differnt manufacture to the water pump and other fittings. You should be able to tell either by checking the caravan handbook or looking at the pump. but that aside:-
From your description it is almost certain that you have a pump operated by a presure switch. This means if the pressure in the pipework drops (for example a tap being opened) the pump turns on to deliver the water. When the tap is closed, the pump continues for a short (may be less than a second but could be longer if you have used hot water) while until it has repressureised the system when the pressure switch turns it off.
The ability of the pump to prodce the necessary pressure is determined by the 12V supply. If you are using an electric hook up, then the 12 system may actually be at about 13.8V - (this is quite normal) and the pump will get up to pressure very quickly and turn the switch hard off. If you are just using the battery without mains, then the voltage will drop as the battery is discharged. This means the pump is not quite so active, and it may struggle to reach the required pressure. It may have a 3 or 4 quick bursts to actually get the pressrue fully up. This could be the chatter you describe.
If you turn the water heater off at night, then as the tank cools down, the volume of water contracts a little and this may be enough to drop the pressure in the pipework, again leading to the pump chattering to restablish the pressure.
The pressure switch can be adjusted to suit changing supply voltages - see your hnd book for details.
If adjusting the pressure switch does not stop the chatter, then you must suspect there could be water leak somewhere. Obvious signs include dripping taps, or drips on pipework joints. water drips from the water heater flue cowl. Even the pressure swich can have an internal leak which unfortunately you cant see as the leaking water simply returns to the water barrel through the hose.
There is nothing wrong with turning both the water heater and the pump off at night, as this is the most economic form of usage, adn it will prevent you being disturbed if teh pump needs to run.
If you are not sure then refer the caravan to a service centre.

 

[xtrailman]

Fitting an accumulator will also help, if you already have one it may need replacing.

Either way we always turn the pump off when going to bed, or out for any period.

Ps. Its normal on a pressurised system for the pump to occasionally top up at night, usually a drop in ambient temperature results in a pressure drop.

 

[graham_somersham]

It might also be worth checking O rings on water inlet connector and that on the filter if you have one. Another fault that can cause the pump to run without the taps being open is an ineffective non return valve allowing the system to slowly depressurise.