boiler fires up, but only for a few seconds...

[Nickpan]

I have a 2007 Halstead Platinum combi, hot tap water is fine, but CH is not quite 100%...
When it fires up, I hear the pump, then the whoomf, but after a few seconds, it all goes quite again. The pipe that goes to rads is very hot, so I know that it kind of works, but I need more hot water to be sent out to rads for longer periods of time. The rads have never been hot as such, just nicely warm. Everyone else I know, has much hotter rads.
There is no thermostat, I use the 'clock' that turns it on for multiples of 15 mins at a time.
One engineer mentioned filters, but wasn't absolutely sure the boiler had a filter.
Could it be its own internal thermostat shutting it all down too quick, or is the pcb mullered?
Nick

 

[Nickpan]

well, engineer turned up, and it all worked fine
He twiddled the heat potentiometer, and the boiler stayed heating for the 6 minutes we stood there.
A new pcb would cure it, but he advised just to twiddle the dial a bit!
I can live with that.

 

[gavinda]

but did the radiators actually get hot?

 

[Nickpan]

Well, an engineers time is money, so we couldn't blast them for too long. After a while I felt a rad and had to let go after 4 seconds which I am confidant is an improvement.
Also, the boiler did seem to be heating for a couple of minutes, whereas before it would fire up then stop within 30 secs, then stay quiet for 5 mins, so it's a leap forward.
Only winter will tell!
£55.

 

[Boilerman2]

Are you for real?? or is this a wind up!!

you have paid an "engineer" £55 to "twiddle the CH pot. then decided not to replace the PCB as you are happy to keep "twidddling"

What exactly has your £55 achieved!

 

[Phill Peck]

He has paid a diagnosis fee he now knows that he will need a new pcb to sort the problem. (although that sounds like an odd diagnosis to that fault to me)

 

[boilerdoktor]

its the fingymabob under the wortsit! always goes faulty on this model ( i can give you my acc details so you can bacs me £40 for this advice ? )

 

[gavinda]

£55 for 6 minutes work

you got done .

 

[Nickpan]

no one seems to have heard of a callout fee!
I'd rather pay £55 and learn about twiddling, than £200 for a pcb just for a fresh twisty nob!

 

[Agile]

I charge more than £55 as a diagnostic fee!

As far as I can guess the pCB is fine and the only problem is that the max CH output had been left at maximum!

It has now been reset to a lower value and that has solved the problem.

Tony