Biasi M110.32sm/e lockout on low temperatures.

[aman113]

So I have had this boiler now for 8 years and it has worked fine for majority of the time requiring few parts to be changed within its lifetime. The long story short, the boiler stopped working a year ago where it went into complete lockout and the engineer spent good 6 hours and couldn’t fix it. He also said the he was unable to bring the CO2 levels within safe range no matter what he tried.


So I did my research and realised that it was the heat building up that caused the lockout and therefore replaced the secondary heat exchanger myself. Since then the boiler has been working, however, it never works at lower temperatures. The boiler starts making noises when the tap is at a low so until now I have had to use higher temperatures to keep it from locking out. Now, I feel the boiler isn't safe as I can smell unused gas from the flu when it is operating and the lockout at lower temperatures. I can never have the heat at low temperatures as it would make noises and lockout which could be due to faulty gas valve.


So I need advice whether to get this fixed or go the safe route and get a new boiler which will give me the peace of mind that my house won't be on fire in the morning.

 

[St0rmer66]

Gas valve out of adjustment I'd say, could be faulty but most can be adjusted back. Get someone different, your first guy clearly had no idea what he was doing.

 

[Agile]

Generally the gas will not even burn if the gas settings are far out.

But some engineers don't seem very good at setting up this type of boiler.

That particular model also needs a proper gas supply within the allowable limits.

Has any of the engineers actually opened the combustion chamber? Possibly something seriously wrong has happened inside.

But when they are properly set up they are very good and reliable!

Tony Glazier

 

[aman113]

The last engineer to visit which was a year ago did open the combustion chamber and tried his best to set the boiler according to the manufacturer settings. However, he was unable to bring down the CO2 level within normal range and said the gas valve is at fault.

What it seems like it is that boiler tries to modulate down with respect to lower demand but is unable to and while doing so makes noises as if it is being starved of gas and then locks out. If I have the tap on full with higher temps set at the boiler, the boiler works fine but gives the thump noise as if too much gas is in the chamber and has ignited all at once. He also suggested the primary heat exchanger is clogged and needs replacing.

 

[St0rmer66]

You could have multiple faults. If the flue ways of the heat exchanger block up then no amount of setting the gas valve will get around it. If it's cleared out and then the gas valve set correctly it's still possible to fix I'd have thought.

 

[Agile]

Those kind of problems can be caused by an engineer who is not very conversant with setting up the boiler and also by a gas supply which has a too large difference between the pressure at minimum and maximum load. That usually results from undersized gas supply pipes to the boiler.

I used to do warranty repairs for Biasi and it was a common complaint, alright I only went to the problem ones, but I came to the conclusion that most engineers have little inclination and experience to bother to set them up properly. They expected boilers to work out of the box without any adjustment even on undersized gas supply pipes.

It would surprise me if there was anything actually wrong with the gas valve apart from being wrongly set up.

Tony