worcester 12ri wont fire up

[CXR100]

got called out to a boiler that would not fire up tonight, a Worcester 12ri in a holiday home. house has been empty for 3 weeks until tonight, in that 3 weeks the property has been affected by a power cut due to wind. now the boiler wont fire up. fan turns for around 5 seconds the comes on intermittently every few seconds for a few seconds until boiler reaches lockout. firs 2 times it went to lockout I had a fault code of "slow flash" which pointed toward pcb because I have tested the gas inlet pressure which reaches 37.8mb (lpg boiler) though this would make sense because of the power cut. but then after resetting it I get a fault code pointing towards temperature sensor or fan connections "fast flash" what are your thoughts about this? and where do you guys buy your pcbs? thanks

 

[GasmanxxxR1]

condense blocked?, or the sump at bottom of the hex?

 

[arran197]

Fan. Common on Worcesters for them to go if the boiler is off for a while. Check for 240v on the pinky purple wire going up to the fan. If it's intermittently spinning with a demand though I'd say it's almost a given it'll be the fan.

 

[CXR100]

you think its the fan? it starts off loud and powerful as it should, then it comes on and off intermittently, no way its the pcb with the power cut? thanks

 

[bigads28]

I'd say it's more likely the board, if the fan runs then 95% of the time it's ok. Is the blue light on of off more on the slow flash?

It's a very different fault depending on which it is.

 

[Millsy 82]

I thought the fan on these modulated before ignition so it might be working fine on full but not on slower speeds.

Had a few problems with the fans on these.

 

[arran197]

The number of times I've been to these with a pcb that someone else has ordered and it's the fan is unreal. The boards are very strong. Test the voltage going to the fan on the pinky purple wire. If you've got a constant 240v then it's the fan. It's by far the most common fault, closely followed by the gas valve. The fan should only run moderately slowly for a second or 2 when powered up on the ri. If it's hunting on and off that's also a good indication. There's a pcb on the fan that relays it's speed back to the main pcb. It's not doing that so the boiler won't fire. It's should eventually got to slow blue light flash.

 

[CXR100]

as its a holiday home it was tonight at me getting back there, phoned my mate for advice before gong , arrived there and switched the boiler on ............ working fine!!!!!!!!!!!! mad!

 

[bigads28]

Typical!, now leg it lol!!

 

[kris]

Easy money,,, Ive had a couple of these where the custard may have knocked it as was just the code plug not making the connection, a wee wiggle and away she goes,, maybe similar

 

[CXR100]

no, pulled it out last time and pushed it back in!

 

[stevetheplumber]

gas?i mean was it lack of gas had it been of