Worcester 24CDi fault - help needed!

[Dorney1]

Hi everyone.

I've recently purchased a new house and two days after moving in my Worcester 24CDi has stopped working overnight.

The fault;

It doesn't seem to be receiving any power. I've checked the power going in and it's definitely there. Add to that, when you flick the boiler on, the green power light flicks on momentarily and goes off.

My friend is a British Gas boiler engineer but he lives far away from me and has tried to diagnose over the phone. He said it would likely be the fuses on the board blown or the board it self.

I've changed the fuses and no luck. Yesterday I went and bought a new board and changed it and still the same problem persists.

Does anyone have any other ideas of what this could be?

Thanks,

James

 

[bengasman]

I've checked the power going in

How?

and it's definitely there.

where?

 

[Dorney1]

With an electrical screwdiver at the junction box.

As I said, I'm confident the boiler is receiving power but for some reason it won't power up.

 

[bengasman]

Power at the junction box means nothing. Dito for testing with a screwdriver.

 

[mbga9pgf]

With an electrical screwdiver at the junction box.

As I said, I'm confident the boiler is receiving power but for some reason it won't power up.

Has the fuse blown in a fused spur? Hidden by kitchen units perhaps?

 

[Andygasman2010]

With the tests you've done it's probably the PCB. Before forking out for a PCB that you won't be able to return it's worth doing a proper L-N-E check on the bottom left of the PCB. For example you may have 240Vac at the L terminal but no neutral i.e. a faulty fused spur. Depends how confident you are of your checks.

 

[Dorney1]

Thanks everyone for your help and suggestions.

I've already replaced the PCB once (on a British Gas engineers advice). Therefore I'm assuming that that isn't the problem as the replacement has had zero effect.

Is there any other tests I can do to diagnose what this could be?

Thanks.

 

[Andygasman2010]

Well if that's the case then obviously the tests you're doing are not sufficiant.

You now need to do the check I described in my earlier post with a multimeter accross L-N-E.

The boiler needs more than just a 240Vac supply to work, a screwdriver with a bulb in it is a rough guide at best.

If you don't have a multimeter or are unable to do this test then you'll need to get someone in.

 

[Dorney1]

Thanks Andy. I think I'm going to wait for my friend to come tomorrow as he does this for a living where as I am an absolute novice at best! (Although I did manage to take the old circuit board out and the new in! Wahey).

I'll get him to do the multimeter test tomorrow and I'll post back if he works it out.

james

Well if that's the case then obviously the tests you're doing are not sufficiant.

You now need to do the check I described in my earlier post with a multimeter accross L-N-E.

The boiler needs more than just a 240Vac supply to work, a screwdriver with a bulb in it is a rough guide at best.

If you don't have a multimeter or are unable to do this test then you'll need to get someone in.

 

[simond]

Does this boiler pcb come with the PSU transformer or did you reuse the old one?

It is worth noting that BG engineers do not pay for their parts so they are very used to ordering first, diagnosing later. Not the first people I'd ask.

 

[Dorney1]

I agree, however, being a friend of mine I thought I'd go to him first as it would be free! (Hasn't quite worked out that way so far! ha ha).

By PSU transformer is that the large blue box that connects to the board? If so, it's still the original - I only changed the PCB.

Does this boiler pcb come with the PSU transformer or did you reuse the old one?

It is worth noting that BG engineers do not pay for their parts so they are very used to ordering first, diagnosing later. Not the first people I'd ask.

 

[Andygasman2010]

Good idea to wait for him.

Before worrying about PCBs, transformers, or anything else for that matter the basic checks need to be done. Shame you've alreadt fitted a PCB.

It sounds to me like the neutral terminal in the fused spur has failed.

 

[Dorney1]

Just to add Andy. I moved in a few days ago but who ever wired this boiler in previous did a hell of a bodge job. There was no fused spur just a power supply to a junction box to a junction box to the boiler. I fitted a fused spur after I changed the PCB as I didn't want to blow a second PCB so therefore I assume that's not the problem.

However, I fitted the new spur inbetween the boiler and the 2 junction boxes so maybe there's a problem further up the chain? If so, would it still show power entering the boiler?

Thanks,

James

Good idea to wait for him.

Before worrying about PCBs, transformers, or anything else for that matter the basic checks need to be done. Shame you've alreadt fitted a PCB.

It sounds to me like the neutral terminal in the fused spur has failed.

 

[simond]

If the neutral has gone open circuit you would not be getting the green light for a second or two.

Sounds like the power supply has gone to me.

 

[Dorney1]

Hats off to Andygasman for the closest guess!

Basically there is already a fused spur but they've put it under the stairs in the living room and fed the wire through the upstairs floor boards down in to the kitchen.

In said fused spur, the neutral wire was just hanging out!

Annoyed that I gave away a perfectly good PCB and paid £50 for the privilege. At the same time I'm happy that I don't need a new boiler.

Thanks for all your help guys.

James

Good idea to wait for him.

Before worrying about PCBs, transformers, or anything else for that matter the basic checks need to be done. Shame you've alreadt fitted a PCB.

It sounds to me like the neutral terminal in the fused spur has failed.