Boiler Not Firing

[fouxdafafa]

Typical. Coldest day of the winter and our CH/HW boiler isn't firing. When I turn HW or CH or both on, with the room stat on, the pump starts but the boiler doesn't fire. I'm suspicious of the fan on the boiler because it was noisy yesterday, as if the bearings were going or something. My question is: does the fan have to start before it will allow the boiler to fire, or does the boiler normally fire and then if it detects that the waste gases aren't being removed then it shuts down? Is there anything I can do to check if this is the problem? I realise I can't go messing around with the gas side of things but I'm happy to probe away with a voltmeter. Boiler is Ideal Classic NF50. Thanks for any advice.

 

[45yearsagasman]

The fan has to work before the boiler fires. There is a fan connection at the pcb in the plastic control housing. You can check there for a fan supply. As it was noisy then best bet is fan has seized and new fan required.
Some boilers were fitted with overheat protection on sealed systems.

 

[Agile]

Changing a fan involves oening the combustion chamber which should only be done by a gas registered engineer.

Those fans can often be lubricated to keep them going for a few days until a spare can be obtained.

Tony

 

[fouxdafafa]

You're right, a bit of lube has fixed it for now, but I'll get the fan replaced anyway. Certainly wouldn't delve in any further, or consider replacing the fan myself, but worth mentioning.