Alpha cb28 problems

[Ned40]

I seem to be joining the growing list of people with problems with a Alpha CB28!

After coming back from holiday I found I had no hot water. The A light was lit up on my boiler and the B light was flashing. I rotated the dial to reset and ran the hot water tap again. The red A light came on again. I then tried my central heating and the A light went off. My central heating works fine but when I turn on a hot water tap it turns the boiler burner off! I no longer have an illuminated A light and the B light is flashing every 5 seconds which is normal.

After reading several posts, I ordered and fitted a new flow micro switch. This hasn't rectified the problem. Even without fitting the switch to the diverter valve assembly and pressing the switch, the burner isn't lighting up.

I phoned Alpha who quoted £250 for someone to come out and for parts. This seems quite steep! I have had to leave the flow micro switch connected to the diverter valve housing but with the wiring disconnected, and turn on the Central Heating to fire up the boiler burner to get hot water when I turn the taps on.

Does this seem like a diverter valve/membrane problem? The boiler is nine years old, I don't want to start throwing good money at it when it may be best to bite the bullet and have a nice new boiler fitted.

 

[ianmcd]

"After reading several posts, I ordered and fitted a new flow micro switch. This hasn't rectified the problem. Even without fitting the switch to the diverter valve assembly and pressing the switch, the burner isn't lighting up.

Read more: //www.diynot.com/forums/plumbing/alpha-cb28-problems.374860/#ixzz2dOJNkZpA


This switch works the other way round if the switch is "pressed in " then the boiler is at rest if the switch is released then the boiler will sense a demand for HW

 

[Ned40]

Thanks for getting back to me.

Whoops, silly me. But even without having the micro switch attached to the diverter assembly, whether I press in the switch or let it go, it fails to ignite the burner. I do hear a clicking noise coming from the boiler so I guess the switch is sending a signal.

 

[Ned40]

The "Read More" link brings me back to this post!

 

[Agile]

So you have successfully determined that you don't need a new DHW demand switch!

You don't want to pay £250 for an inclusive fixed price repair.

You have already spent about £25 for a switch you did not need. So what do you plan to do next?

How about a good local independent engineer?

Tony

 

[Ned40]

Hi Tony

Yes, a good local independent engineer is my next step. I am now asking around friends/neighbours for recommendations.

Cheers

 

[ianmcd]

well considering that Alphas head office is in Kent I would just give them a call and see who they recommend you are spoilt for choice where you are

 

[Ned40]

Alpha were no help. I phoned them and all they would do is offer me a service contract with a third party for £250 for the visit plus parts or £300 to include 12 months cover.