Truma Heater Problem

abruzzopietro

The Truma Ultraheat 3002(P) in our caravan has ceased to provide any heat on either the 1000w or 500w settings (it still works fine on the 2000w setting).  I believe that there is only one heating element and therefore suspect that the controller/thermostat
is at fault.  I have however seen references to relays and am not sure whether these could be the problem - or where they are located.  I would be grateful for any advice as to how to test for (and resolve) the problem.