Woke up this morning to no electricity in the house. Check CU and find main breaker tripped. Reset this and all ok. Tripped out again at lunchtime, same procedure and all ok.
Late this afternoon it tripped again and would not be reset.
By trial and error I have found that the fault is definitely in the gas boiler wiring.
Switched all off at the programmer. Try the DHW - drain a load of hot water - boiler fires up, no problem there. Turn DHW off. Try CH with roomstat turned down - no problem
- turn room stat up to call for heat - electricity trips out.
Am I right in thinking that the problem probably lies with either the roomstat or Danfoss CH motorised valve? Unfortunately the wiring for both is subfloor. Roomstat wiring is totally inaccessible, CH valve can be got at with a grovel.
I don't know how to test either. Any thoughts or other suggestions for a remedy would be much appreciated.