B/V

▶ Check if lead is disconnected from the temperature limiter.
▶ Check the high limit of the temperature limiter and the harness for continuity.
▶ Check the flow temperature to confirm actual temperature (may have tripped out at lower temperature, leading to safety temperature limiter fault)
▶ Check the system pressure and top up as required.
▶ Check if air is trapped in the system and in the boiler.
▶ Pump seized/not running: check the pump for failure or blockage.
▶ Check if blockage/restriction within boiler/pipe work restricting the flow.
▶ Check gaskets/seals for possible flue leakage.
▶ Check HEx for polution.
▶ Check gas-air ratio setting of gas valve.
▶ Review EPM/appliance/XHC.