Technical

[DenistheMenace]

On our last outing - our Truma blow air heater stopped working when on electric, on examination no rcd's had tripped, has anyone experienced this problem and found a solution?

 

[gary]

These are the main reasons for problems in no specific order;

The elements are switched on and off by relays and the contacts burn out, particularly the two 1kw relays. If this happens you may think you have it set to 2kw but only one element is working, finally perhaps leaving you with just 500w working when both 2kw and 1kw settings no longer work.

(Note, relays will still be heard to 'click' but unless you have heat, their not working)

The 12v for control also comes from this board and the transformer sometimes packs up, apart from no heat, you will lose the green light in the switch if this happens

Also if no heat is forth coming, there are two safety thermostats, one at least of these has a habit of self destruction which stops all heating on electric! If the lower 125C thermostat trips, it automatically resets when it cools. However, the 175C limit stat is a 'self hold' and cannot reset once tripped until the mains supply to the heater is switched off, once mains supply is off, it will then cool and reset automatically.

Finally, the mains isolation 'fused switched spur' can loose it's connection through the built in fuse, the fuse is not the problem but the fuse holders connections that stop making contact with the fuse

The main control switch itself seems generally reliable but the odd one does fail, the fan control switch when set to 'A' should make a positive connection and not switch on and off at the merest touch.

 

[DenistheMenace]

These are the main reasons for problems in no specific order;

The elements are switched on and off by relays and the contacts burn out, particularly the two 1kw relays. If this happens you may think you have it set to 2kw but only one element is working, finally perhaps leaving you with just 500w working when both 2kw and 1kw settings no longer work.

(Note, relays will still be heard to 'click' but unless you have heat, their not working)

The 12v for control also comes from this board and the transformer sometimes packs up, apart from no heat, you will lose the green light in the switch if this happens

Also if no heat is forth coming, there are two safety thermostats, one at least of these has a habit of self destruction which stops all heating on electric! If the lower 125C thermostat trips, it automatically resets when it cools. However, the 175C limit stat is a 'self hold' and cannot reset once tripped until the mains supply to the heater is switched off, once mains supply is off, it will then cool and reset automatically.

Finally, the mains isolation 'fused switched spur' can loose it's connection through the built in fuse, the fuse is not the problem but the fuse holders connections that stop making contact with the fuse

The main control switch itself seems generally reliable but the odd one does fail, the fan control switch when set to 'A' should make a positive connection and not switch on and off at the merest touch.

Thanks Gary, very interesting, we will investigate your ideas on our next outing, cheers.

 

[Chris_374413356]

If these are are common and known faults, why doesn't Truma design these problems out of their heaters, after all, a caravan heater in real terms should last indefinitely.

Although, perhaps bad for sales!

 

[GrahamDerby]

If these are are common and known faults, why doesn't Truma design these problems out of their heaters, after all, a caravan heater in real terms should last indefinitely.

Although, perhaps bad for sales!

i think your last few words sum it up, the whole industry is out to make as much money out of us as they can.