Alpha HE 33 issues!

[Nvq level 3]

Hi,

ive been to the above boiler and not to sure what's going on with it, I think the board may have lost control but see what you guys think.

boiler whilst on central heating fires for a few seconds then drops out this keeps happening all the time, switch over to hot water it either does fire and does the same or it doesn't. After taken the burner case off it did stay burning for possibly 5mins then cutout again!

A and B start flashing together while this fault is going on.

could also be a thermistor maybe thinking it's reached temperature as well but not 100%.

any info would be great.

thanks.

 

[Anton]

According to Alpha's fault chart, A + B flashing on/off together is either blocked flue or fan fault.

 

[Nvq level 3]

I'm getting 240v to the fan? Maybe it's not pulling enough or even venturis? (Not sure how to spell that)

thanks for reply

 

[Anton]

Blocked condensate trap ?

 

[Nvq level 3]

Possibly, but would that cause it to keep cycling on and off? I've had that before and it just doesn't fire.

 

[GrahamM]

The fault guide on these is actually quite good as I have found in past. You need work your way through step by step proving each component etc. Even give you the thermistor readings.
Only once after checking everything else was functional and still getting both lights alternate flashing did I decide on PCB which was correct diagnosis.

 

[Alpha man]

Condense problem, link out the two brown wires on the secondary heat exchanger by the fan,

 

[Nvq level 3]

Thanks for the feedback, will have a look at the condense and will let you all know how it goes.

 

[Nvq level 3]

By linking these wires out what should I expect to happen? thanks

 

[Alpha man]

Try it and find out!!!!!! LOL


If it's a condense problem, then A-B will stop flashing and boiler will work.

 

[Nvq level 3]

ok cool, thanks a lot will report back to let you know.

 

[Alpha man]

Just re read you're Original post, have you tried cleaning the flue Venturi?, if that's ok, then either the APS and/or PCB is on its way out!

 

[Nvq level 3]

working through the fault finding process I got to testing on the board for 24v which I wasn't getting implying its the board but before jumping straight in with the board I wanted to see what other possibilities there was, as I've done a similar thing before to then find out it was a cheap thermistor! not on a alpha though!

 

[Nvq level 3]

so it says test across m5 connector terminals 15 and m6 connector terminal 20 to get 24v dc which I wasn't getting.