The Truma heater in my 2001 CI Riviera carries on sparking after the heater is lit , I am happy with removing and replacing the burner and micro switch , i see the switch is availiable seperately, is that the likely suspect? .the ignitor box produces strong regular sparks when tested on the bench but the spark is weaker and less regular when installed so i suspect that the earthing is poor, i suspect the high voltage earths in the micro switch and back to the ignitor box through the two low voltage leads, there is no where else for it to go.HAs anyone stripped and re-assembled a mico switch?.