RE: Drill Pad24 May 2021 17:08
New one, sounds like he was baffled by the plug..;)
Lights on? I assume there were lights on, but no hot water, so power on. not fuse blown..
Water pressure 1st check..
If its a condensing boiler there is a drip/overflow/blowout pipe going outside which must be clear, could be blocked, sealed by certain insects..like leaf wasps, they can plug it, probably not this time of year though.
On startup..
If its a combi boiler the exhaust fan must run before its allowed to ignite the flame.
If the fan runs it must operate a vacuum switch which is connected by an air pipe to the fan, and then to atmosphere in the chamber.
If either of these fails you wont have ignition, the fan might run to slow, or not at all, the switch may have failed, or the piping connecting it..the switches wear so the initial firing of the boiler can trip the switch off when the pressure changes in the combustion chamber..
There will probably be an exhaust/flue warning light flashing/on if these are the issue..
You will be able to hear the fan, and possibly the switch clicking..
Did the boiler run when the engineer had the covers off?
The flue also needs to be clear, and seals good.