from ex thorn engineer
the supply to the pump live is via the (PORS) pump over run thermostat at all times-- when cold the pump picks its live supply from the "switched live" via the PORS when the stat gets hot the supply comes from the permanent live via the PORS. If you are sure the pump is not live then I'm afraid the PORS is faulty -as a temp measure change the wire to the pump at the boiler control panel onto the switched live. This will feed the pump anytime the boiler is switched on but you will have no overrun. May result in over heat thermostat operating and shutting pilot off due to residual over heating
this is a very old boiler -- seen hundreds of them
make sure all three cables are sound and are in continuity from PORS to the control board - no loose or damaged wires.???
dave b
dave broadbent, June 2007
