Biasi Riva Compact M96.24SM/C2 ignition fail after a few minutes

After a few minutes running hot water, the left hand operation light flashes quickly, the water goes cold and switching the boiler off and back on again gives an ignition fault indication with the two outer lights flashing and the centre light on. Further attempts at switching on and off have no effect, goes straight to the ignition fault indication. After a few hours or so, it will decide to work again for a few minutes before repeating the fault. Is this likely to be the ignition pcb or perhaps a sensor? We paid a heating engineer to check it over. He made no attempt to fix it, all he could say was it would be easier to replace the boiler - total waste of time and money, I think he could only install boilers not fix them. We are in London SW16 - any suggestions would be appreciated or perhaps someone could recommend a reliable heating engineer who can fix Biasi boilers.

 

Clearly you engaged someone without any diagnostic skills!

All he was there for was to try to get you to agree to him fitting a new boiler for you.

Your boiler is totally repairable!

But there could be several different causes of your fault and many engineers could be a little stretched to actually find the fault.

Get someone who specialises in repairing boilers!

Tony

 

That's exactly what we thought, he was only interested in selling a new boiler.
Needless to say we are wary of getting another "heating engineer" out to tell us to replace the boiler. I gather from what you said, that engineers actually capable of diagnosing boiler faults are few and far between, so how do we find the good ones rather than the installers?

 

why are you saying its a pcb or sensor fault who said this ? , this fault should be able to be fixed , the ignition fault could have several reasons to fault . get someone in who knows what their doing because another boiler may not be necessary and the pcb is the last thing to change atm .

 

thats a good question tbh , ask family and friends for recommendations .and don't just go on price maybe one that does a diagnostic price first (but not foolproof ) a good indicator thou .

 

Sorry, but I asked if the pcb or sensor were likely suspects, I didn't say they were the cause. As a retired electronics engineer, I naturally look at areas that I have experience of.
Asking family and friends would be the natural course of action, but having just moved here from the north east, we have no one local to ask. So again, can anyone suggest a competent engineer in this area?

 

People who post here always like to ask if the fault could be caused by X or Y.

Its totally irrelevant because its whatever part(s) is causing the problem.

In your case its unlikely to be a temperature sensor as they would give rise to a fault indication for a sensor.

You seem to have a fault which is affecting ignition or giving rise to an indication of an ignition fault. ( They are not the same thing! )

Regardless, all you need is a competent engineer who specialises in fault finding.

The fault could be minor or even multiple. Both Biasi and British Gas have fixed price repair arrangements. BG don't always seem very good with Biasi boilers.

My expectation is that it is relatively minor and will not require any spare parts! If that is the case then an independent will be about a third of the price of one of the fixed price firms. But then I have not seen your boiler and there could potentially be several causes.

Tony

 

not always in this case

 

I would disagree with you in the case of this particular model!

In any case I did say it was "unlikely" !

But I would add that while repairing perhaps 1000 of that Biasi model I have never seen a temp sensor cause that particular indication.

In fact its about the only fault which the PCB seems about to always report correctly.

Tony

 

edited due to wrong boiler I'm talking shyte

 

I said it was very unlikely that a temp sensor could give rise to a lack of ignition and ignition fault indication.

Others would say "never" but I always leave scope for a first time new fault.

But I was not discussing when a faulty sensor might not give a sensor indication.

Engineers love to guess at faults on sensors which in practice don't occur. Sensor faults in practice are limited to being open circuit and having high resistance contacts. They don't change their curves which is often suspected although high resistance contacts give that effect. But that is not a sensor fault but a connection fault.

That said I did once encounter a Biasi where the sensor was not following its curve. It was not the NTC element itself but water had leaked inside it so was providing a parallel circuit as well as conduction to the earthed case. But that is extremely rare indeed. Unlikely any BG engineer would ever encounter that in 30 years of working.

 

I've just looked at the manual and i was thinking off wrong boiler
but in this case the sensor appears not to be an issue

 

I am surprised that you consider that suggesting probable causes from symptoms is irrelevant. From my own experience of fault finding, albeit in a different field, it is quite normal to identify the likely causes of the fault from the reported symptoms, which are then eliminated in turn until the culprit is found. I would think that this approach would apply to any complex piece of equipment. And just to be clear, I never mentioned a temperature sensor, I queried if the pcb or A sensor were likely to cause the symptoms that I reported. With my limited knowledge of boilers, I would expect to have a variety of sensors including flow, temperature and flame failure sensors.
Anyway, we took your advice and contacted Biasi who gave us a couple of local engineers and having contacted one, he is coming this evening. Assuming he fixes the boiler, I will report back in case it helps someone else with a similar fault.

 

Boilers only have temperature sensors as discrete components.

Flame failure is sensed by the PCB from a probe in the flame.

A boiler engineer with a little experience jumps to the most likely cause first as that's quickest.

I am expecting him to disconnect a wire from something which will cause the boiler to work and then investigate the component he disconnected the wire off.

Of course he may not be so familiar with the boiler and might take a little longer.

Tony

 

No that's just Tony being infuriating.

Like this.