Isolate Mains Power to appliance as per TOPs P4
Remove functional case door
Remove functional case door
Observation:
Check the flow and return sensors are fitted correctly have sufficient heat sink compound and are making good thermal contact.
SENSOR FITTING AND HEAT SINK COMPOUND
Flow sensor
Return sensor
Dry fire sensor
Check for sufficient heat sink
compound and correct fixing
compound and correct fixing
Isolate as per TOPs P4
and refit as necessary