no heating

[crooks]

Baxi combi 105 he hot water is ok but central heating wont come on?
all the neon lights seem ok (no flashing fault indicators) when i switch to c heating and water turn hot tap and boiler ignites but wont switch to c heating
could be pcb but its expensive if thats not the fault? help!regards John.

 

[gas_man_gaz]

would be surprised if it is the pcb, have you checked all controls are calling for heat? (room stat etc).
if so what lights (if any) are illuminated on the front of the boiler wen just the heating is on?

 

[crooks]

Sorry i should have said its my sons c/heating and will check the lights tommorow was working untill we replaced radiator but could be a coincidense
I think i will need a meter to check.regards John. ps will check the room stat first.