Alpha CB 24

[DirksPlumbing]

Hi Gents, I am looking for some advice on a mysterious fault on an above boiler. My first suspicion is that the fairly new PCB has went belly up again. It got changed last September.
Giving the boiler a second life but obviously not for very long.

Basically the boiler goes randomly to lock out with A flashing, B off indicating an overheat situation.
At the same time you can touch the heat exchanger without burning yourself.
The fault happens roughly every 10th start up. The boiler seems to be starting up but B just flashes very briefly. It cycles that a few times and if it does not manage within a reasonable time it goes on lock out as described.


Someone came across that before?

 

[Alpha man]

Change the air pressure switch!

 

[DirksPlumbing]

Change the air pressure switch!

Thanks for the quick response. Your name suggest that this is based on experience?
It makes me wonder if that is not another case with excessive flue length. Or restrictions in the air intake.

 

[Alpha man]

Thanks for the quick response. Your name suggest that this is based on experience?
It makes me wonder if that is not another case with excessive flue length. Or restrictions in the air intake.

No, just a cheap air switch!! Lol

 

[Dotty]

Moved to the private forum.

Please be careful where you're posting these chaps!

 

[DirksPlumbing]

Moved to the private forum.

Please be careful where you're posting these chaps!

Sorry and Thanks. Could there not be a button to safely post things?

 

[DirksPlumbing]

No, just a cheap air switch!! Lol

Well, switch is on order. Find it confusing to find the relation between an overheat fault displayed and a faulty pressure switch being the reason.

I let you know on Wednesday how it went.

 

[Alpha man]

I know, I first had this fault years ago, took me about 10 visits to get to the problem!

The best bit is, Alpha still don't recognise this problem!

 

[DirksPlumbing]

Well, it seems you were right. I instructed the customer to let me know of even the slightest problems. No call/message by now.

But cheap is debatable. For the price of one Alpha air pressure switch I can buy around 3 Worcester pressure switches.

 

[Petefinny]

I had this problem after fittin a new board, found out it was the new board that was causin the lock out, sent the board to alpha and they agreed that it was faulty

 

[Alpha man]

Well, it seems you were right. I instructed the customer to let me know of even the slightest problems. No call/message by now.

But cheap is debatable. For the price of one Alpha air pressure switch I can buy around 3 Worcester pressure switches.

It's a cheap air switch, but the price isn't!!