Last week-end I decided to do a bit of service work on the caravan. It was all going well until I connected up the mains - pop. After a bit of "process of elimination", the source of the trip is the Truma water heater. I put a break in the cable to check the wiring and it is fine. Next thoughts were the heating element, I measured 60 ohms between Live and Neutral and open circuit between Live/Neutal and ground. This doesn't explain trip unless there is a surge or a fault on the trip RCD. The other thing that bugs me is that I would expect the resistance between Live and Neutral to be open circuit until the Truma is switched on mmmmm... .
an element is the normal problem when it trips out.could be damp inside the element.run it on gas for few hours and try again. the other thing is that if you have the electric fire on 2000 and then switch the water heater on it can trip out.ours does,not a problem saves me going for the warden.
Post last edited on 14/04/2012 16:45:04
------------- the only silly question is the one you do not ask.
Discounted Insurance Quotes for UKCampsite.co.uk visitors! Up to 12.5% off!
Yes, I am assuming I am measuring the resistance of the heating element. It is an 850W Truma, so 60 ohms is about right. I currently have it running on the gas. I'll try running it on electric in an hour or so.
After running the Truma for a couple of hours on the gas, I switched over to the electric, and it stopped tripping - great. Now the bad news. I left unit off all day yesterday and came back to check it this evening. It is tripping again :-(.
If anybody has any other ideas they would be much appreciated. I think a service is probably the nect option.
It's probably caused by a leaky gasket or condensation,it seems that the element is OK you possibly could remove it and reseal it but I'm not familiar with the workings so not sure if that is possible.
I think you are right in it being condensation /leaky gasket. It maybe if I run the gas on and off for a week or so it may clear. I'll persevere for a little longer and see what happens.
I had the same problem with my water heater and the testing appeared to defy logic. Everything tested out Ok on multimeter (don't ask about readings - my brother is an electrician and I wasn't sure what he was on about!!), rechecked its function hooked up to a generator and it worked fine. The next time I used it on holiday it just kept tripping. I had a new element fitted and it has been fine since.
I think, if in doubt, stick a new element in.
60ohms across the element is correct but by design you should have near infinite resistance between live/neutral element connections and earth.
So unless the element connections are damp, the element needs replacing
In reality, the RCD trips at 30 milli amps so anything above 20k ohms resistance to earth should not trip the RCD.
However many multimeter's don't read that high and only show open circuit
You will only be able to carry out a satifactory test of the heating element by using a meggar not a multimeter. The difference being the meggar will test the earth resistance and continuity using typically 500 volts whereas the multimeter is "driven by a few volts.
It sounds to me that the element is breaking down under load something which the multimeter cannot provide.
Hi all, we are having the same problem kept tripping while on holiday, we also have a trauma water heater, can anyone tell me how to change the element ? Thanks