Ariston microgenus 27 mffi

[Hypnoman]

Hi, Can anybody help, I run the heating or hot water the boiler ignites and after 5 second cuts out. The red light is then on after resetting the same problem happens.

 

[Agile]

It seems the boiler is failing to detect the flame ( thats if its really lighting! ).

Could be th PCB or a vast number of other things which need a gas registered engineer.

Tony

 

[Hypnoman]

Hi. Thanks for your reply, the boiler is igniting the big blue flame indicates this. Can the flame detection device be checked without opening the boiler up. I have a new boiler being fitted in 6 weeks so I do not want a great expense of having this repaired if it's something simple. Thanks

 

[bengasman]

You can try to hear the sparking sound before it locks out. If the sparking stops before the lock out, it could be something else. Not much chance though.

 

[Agile]

Its probably the PCB at fault but there are some simple cheap causes within the combustion chamber which a competent gas engineer could check.

These dont seem very reliable boilers judging by the number I get called to.

Tony

 

[Hypnoman]

Thanks to all, Can the flame detection device be tested in situ if I put a volt meter on the lead what should it read. I am reading about 0.75v but am I testing it correctly. Thanks again

 

[Hypnoman]

O.k Thanks everybody..... problem solved by process of elimination turned out to be a small split in the compensator pipe. Thanks again.

 

[bengasman]

O.k Thanks everybody..... problem solved by process of elimination turned out to be a small split in the compensator pipe. Thanks again.

What is a compensator (pipe)?

 

[Hypnoman]

www.heatweb.com/pdf/Ariston/microgenus_servicing.pdf Section 1.4.3

 

[bengasman]

Ah, had not thought of that bit. I call it: "the dufa that goes from A to B."
Guess that was not the correct name then.
Don't think I have ever seen one of those pop.
Did it look like mechanical damage? Dried out? Melted?

 

[Agile]

As that only provides a reference pressure for the gas valve then I dont see how it should have caused any fault!

If the flue is a little longer then the case pressure can be a little different from the ambient inside the building.

I suspect there may be another underlying misadjustment fault!

Tony