potterton prima f50 wont fire up

[snott36]

Hi to everybody on the forum as this is my first post.
I have a potterton prima f50 boiler and it has just stopped working I have tried resetting it. The pump upstairs is running ok the timer upstairs lights up as normal. I have put the hot water and heating on continous and turned up the thermostat. I have removed the cover and checked for power with a multimeter its got 240 volts to the boiler i have spun the fan and that isnt seized. When i turn on the power you can here a relay click as normal but the pilot light doesnt light up all you get is a humming noise and nothing else. has anyone got any ideas on what is the problem or can anyone give me any advice on what voltages i should have where so i can try and diagnose the problem.
Many thanks in advance
Scott

 

[gas4you]

Try testing for 230V at the fan terminals. Humming noise often points to the fan even though you can spin it.

 

[snott36]

Ok i will test the fan as i dont think it is running. would the fan not running stop the boiler from working.
Thanks Scott

 

[Agile]

Er... yes it would otherwise they would leave the fan out of the design and save a lot of money!

Tony

 

[snott36]

What i meant was would the fan not running stop the pilot light from lighting and the boiler from running for a liitle while as i am not sure how the boiler knows if the fan is turning.
Scott

 

[gas4you]

The air pressure switch senses the pressure from the fan spinning and then tells the boiler it can go to the next part of the ignition cycle.

 

[snott36]

Thanks gas4you thats what i wanted to know.
After checking it last night the fan isnt running and the humming noise is coming from the fan. I ordered a recon fan of ebay for 27 quid lets hope it cures it thanks to everyone on the forum for there help.