Combi boiler CH nightmare!

[stub77]

Hi All
I'd be grateful for some pointers/advice as I am struggling to get an issue resolved.
Boiler is a Broag/Remeha Selecta combi, HW works, CH does not.
So far the plumber has replaced the diverter valve and its actuator/motor and now the main heating pump.
Still no CH. He thinks it's a blockage in the heat exchanger but this sounds more like a best guess.
Thermostat is calling for heat, signal received ok, boiler won't fire. Pressure is 1 bar approx.
I'm not sure why a blockage would stop the boiler firing up? I can understand it might cause a lock out if something overheats but it's not firing at all when CH is requested.
Historically it does make some loud vibrations, prior to the above parts being replaced, and the overflow has dripped a little (outside the house) but generally has been reliable until now.
Any thoughts? My plumber is about to concede defeat.
Thanks
Stuart

 

[Agile]

I think that you have had a parts changer with no diagnostic skills.

BG do a fixed price repair for about £290 you should have called them.

Or better any local independent.

Even if I came to you, I would expect the total cost to be no more than £240 unless the PCB was faulty which seems unlikely.

But that would not cover very serious sludge issues which are always a possibility.

Tony

 

[stub77]

Thanks Tony.
I feared the same, we do need to try someone else.
Costs wise I have been quoted £300 for the valve/actuator (fitted) and an additional £90 for the pump. So I am already looking at £400 without a fix!
Good to know of the BG option, a learning curve for me...

 

[Agile]

There is always the argument that you should not have to pay for parts which do not fix the boiler.

Parts changers usually get the client to buy/pay for the parts they want to "try".

I would never charge for a part which was not required. But then as an independent I can take the time to properly diagnose the fault.

Tony

 

[stub77]

Handily I haven't yet coughed up any money...
I was suspicious from the point where he turned up with his 'expert' mate (who is the one that is gas safe registered) who, after a bit of hot water turning on and off and some feeling of warm/cold pipes, concluded it was the diverter and actuator... I'm clearly no expert but from reading case studies online I expect there was a bit more diagnosis that should have gone on.

 

[St0rmer66]

BG is £199 by the way, not £299.

Is it a wireless thermostat? Sounds more like the receiver to me! Just because the light comes on saying it's got the signal doesn't mean it's actually giving the voltage to the boiler (this happens a LOT, very common fault which can be proved within minutes with no parts guessing!).

 

[FiremanT]

Handily I haven't yet coughed up any money...
I was suspicious from the point where he turned up with his 'expert' mate (who is the one that is gas safe registered) who, after a bit of hot water turning on and off and some feeling of warm/cold pipes, concluded it was the diverter and actuator... I'm clearly no expert but from reading case studies online I expect there was a bit more diagnosis that should have gone on.

To clarify, the guy you called out is not gas Safe registered?

 

[stub77]

He personally isn't, but works with a 'partner' who is (I checked his number).
Thanks all for your input. A second plumber has now looked at it and has solved the issue by bypassing the remote thermostat. A 5 minute fix! New thermostat being fitted (not a remote one).
Thank you all very much.