Hi all,
Have a frustrating boiler problem that maybe someone can help with? Had a second hand Worcester 28i Junior installed at our house. Came from a fairly decent company, tested and 'working'. Once installed (a month later by reg. GasSafe), boiler works as expected except shortly goes into heat exchanger lockout due to the pump not circulating. Pump can be powered by a fused test lead direct to the mains and boiler works perfectly for CH and HW, controlled as expected by a new plumb centre clock. Tested PCB pump connection and found no power throughout startup going to pump. Company sent us a new PCB which was changed, but problem still persists. What could be telling the PCB not to power the pump? Many thanks for any help!