Biasi Overheating + Pipes?

[Assist]

The model is a Biasi M90F 24S.

Problem:The boiler cuts out and requires manual reset button. It then overheats and repeats. The DHW is fine and doesn't cause tripping.

Thought it was a circulation problem. So a powerflush was done, but it hasn't solved the problem. Looked at the pump and its weak, running at about 40 (ohm) so thinking of replacing pump? As first option Yes/ No?

or

Is it more likely the PCB that needs to be changed? Second option.

In addition the piping looks like it needs upgrading as it goes from 22m to 15m, not sure if this really matters?

Best next step would be welcome. Thanks..

 

[bengasman]

Changing parts until the problem disappears is not a good way to tackle a problem, you will be cheaper off getting a breakdown specialist in for this kind of thing, and it will be a lot quicker too.

 

[Assist]

thanks for the reply.
I have had two gas safe registered engineers around to check the boiler. The first said we needed a power flush, which did help but not solve the problem. The second is suggesting replacing the pump and/or the PCB.

Could it be anything else before we go ahead with replacing these parts?

And to limit costs, which would you do first?

Or is there another way to go about this without spending another £80 on another engineer who may suggest something else altogether!

Looking forward to your reply - thanks for your help in advance

 

[libby lou lou]

Could you not get an engineer out on a no fix no fee basis?

If you first did that, you may of saved a few quid, and not be in the situation your now finding yourself in.

First thing i would of done. I know it's not much help, but would you take your car in a garage for repair and pay for it unrepaired?, that's what youv'e just done.

 

[Assist]

Thanks Libby, didn't know you could do that? Will definetly try and track if thats feasible. Will keep it in mind.

If you've got any suggestions of a company that provides such a service I would love to get it in touch.

That would be helpful. Thanks....

 

[transam]

Boiler overheating ?? causes lack of adequate water circulation around heating circuit ?? boiler is ok ?? as hot water works ? same pump , same heat exc ?

but under the control of a different boiler stat , that sends information back to the control pcb which than modifys the heat out put !! Are

all rads turned on ?? trvs ? on max ? boiler heating stat is it on max eg 90 degs c with trvs all turned down ?? is there a by pass on system ? is the one in boiler ok ??

 

[Assist]

Hi Transam,

Thanks for the reply? I don't know if the other engineers checked the "bypass" on the system or in the boiler.

If their ok, do you think it's possibly the pump. If their not I'm guessing they need sorting.

Or do you think its a different boiler stat?

Really not sure what to do and reluctant to waste money. But need it sorted as Wife's due with our first next month. And I have to get this resolved.

Really appreciate any advice on what would be the best thing to do.

Thanks again!

 

[transam]

Pump it is possible , but the pump is working for the hw O.K ??

On this model if my mem serves me correctly ?? the max temp of hw u can get is 55 degs c ( I think ?) which means max temp the boiler will get to when in the hw mode is 75 degs C approx as indicated on the temp gauge !

in the ch mode the boiler is capable of heating the water to approx 90 degs C if the ch stat is on max , is it ? if it is turn it down !

The high limit over heat stat will cut out at approx 105 (ish) degs C . If the boiler cannot dissipate the heat it is creating than it will lock out , there must be a minimumn flow of water across the heat exhanger , there is an inbuilt by pass on this model , but if all the rads have trvs , or are turned off , on low ?? it may not be sufficient ?

the ch out put is adjustable eg the ch out put can be adjusted to provide a max out put in order to serve the needs of the c h system ? variuos gas pressures may need to be checked min / max ect ? ultimately the control board may not ?? be reading the information it recieves correctly from the temp sensors ??

(Agile may well pick up on this thread I think he knows a little bit about Biasi's )

 

[Assist]

Pump it is possible , but the pump is working for the hw O.K ??

Reply: Yes - The water works fine

On this model if my mem serves me correctly ?? the max temp of hw u can get is 55 degs c ( I think ?) which means max temp the boiler will get to when in the hw mode is 75 degs C approx as indicated on the temp gauge !

in the ch mode the boiler is capable of heating the water to approx 90 degs C if the ch stat is on max , is it ? if it is turn it down !

Reply:No, its not on max. Tried turning it down, made no difference.

The high limit over heat stat will cut out at approx 105 (ish) degs C . If the boiler cannot dissipate the heat it is creating than it will lock out , there must be a minimumn flow of water across the heat exhanger , there is an inbuilt by pass on this model , but if all the rads have trvs , or are turned off , on low ?? it may not be sufficient ?

Reply: Turned the rads to fully open and very low but again no change.

the ch out put is adjustable eg the ch out put can be adjusted to provide a max out put in order to serve the needs of the c h system ? variuos gas pressures may need to be checked min / max ect ? ultimately the control board may not ?? be reading the information it recieves correctly from the temp sensors ??

Reply: Adjust the CH output, is this easily done and will it work? Or would it be the PCB is the cause or limiting the output in pump?

I don't really want to get this wrong. So thanks for the help-hopefully agile will be able to add thoughts too. Anyone in Hertford area?

 

[Agile]

So what did you do?

As an engineer I need information to diagnose faults!

As a start in your case I would want to measure the ACTUAL temperature it cuts out at!

Tony

 

[transam]

So what did you do?

As an engineer I need information to diagnose faults!

As a start in your case I would want to measure the ACTUAL temperature it cuts out at!

Tony

Think u may be a tadge late agile ??

3 years to late ?

 

[Agile]

He never posted what the fix was!

Its an "open ended" thread!

Tony