Biasi 24S: Hot water cuts out the heating

[willtry2010]

Hi

I continually have problems with my Biasi 24S boiler.

If the heating is on and I turn on the hot tap, the heating cuts out and the water runs cold from the hot tap. To then get either of them to work, I have to leave the boiler for a few minutes as it will not refire. The hot water will not fire up the boiler whilst the heating is on.

I've had the diaphragm changed and sometimes,the boiler works fine but it is so tempramental. There is no pattern as to when it works or doesn't work!

Does anyone know what the problem could be? Thanks!

 

[Agile]

Its difficult to imagine what you seem to be describing.

However, in front of the boiler its very easy to diagnose fault(s).

Tony Glazier

 

[willtry2010]

Thanks Agile

Don't know how else to describe it apart from what i've written already. I have had a corgi boiler man here a few times and he can't see what else it is apart from changing the diaphram or getting a new boiler.

However, the problem seems to have got worse as the heating cuts out after about 10 mins regardless of whether i use the hot water or not.

Do i really need to get a new boiler??

Any help would be greatly appreaciated.

 

[Agile]

Your boiler is totally repairable!

Whilst I dont know whats wrong from what you have said, its only a boiler and all boilers are repairable and that model is one of the most stable and reliable boilers ever made.

Tony Glazier

 

[gasbanni]

When you get the hot water to work feel if you get any hot water down one of the heating pipes at the same time doesnt have to be a lot. post reply.

 

[Agile]

How do you think that could occur on a 24S ?

 

[willtry2010]

HI Tony

My boiler man is totally lost too - he says he hasn't come across this problem before and as it's intermittment, it's hard to wrk out the actual problem.

He's suggested a new PCB board and other electronic parts but he said he won't know if this will fix it.

I'll try to explain again.....

The heating is on and running and fired. I turn the hot tap on and the flame goes out. Normally, turning the hot tap on would refire the boiler but if the heating has been on, it doesn't refire. The water will run cold. If i turn the tap off, the heating is still switched on but doesn't refire either. I then keep switiching the CH on, off, on, off until it eventually refires. I normally hear a click before it works, as if a switch is finally resetting itself allowing the CH to now work.

This doesn't happen all the time. Occasionally, the hot water tap will refire the boiler whilst the heating is on.

Last night, a new thing happened where the CH would only stay on for up to 15 mins and then cut out. It would not refire and the rads would go cold. Again, i have to wait till i hear this click before it will work. I can spend ages switiching it on and off but it won't refire until this click inside happens.

I don't know if it is getting too hot and cutting out and won't restart until the temp has come back down.

Do you think there are some parts i should try first rather than all parts?

Thank you!

 

[Agile]

I appreciate that you are well describing the problem but that does not mean that I can 100% diagnose ( guess ) the problem. I can only do that in front of the boiler.

Its most likely that the pump proving switch is not being activated. Its easy to see if thats the cause by removing it when the boiler is "off" and activating it by hand.

If your engineer cannot diagnose faults on a simple boiler like that then he deserved to be called a plumber because he has none of the skills required of a boiler engineer.

Tony

 

[willtry2010]

Hi Tony

I think you are in West London - any chance you could head east? To Leyton? Or know someone that could?

Thanks
Gaynor

 

[willtry2010]

Boiler man says the pump is working. He checked that.

 

[Agile]

I am in NW London but often go to East London. In fact if you search for my reviews of restaurants in Leytonstone you will find some.

However, if you want to engage me to fix your boiler then you need to contact me off the forum from the contact details in my profile.

Tony Glazier

 

[gasbanni]

How do you think that could occur on a 24S ?

Because I've had it happen twice on Biasi's ! I'm asking if when the hot water demand is on does heat transfer occur down the heating circs to the extent that it its noticable. I'm not stating that it is happening I'm asking does it. Intermitant jamming of the diverter could possibly cause problems similar to decribed which would cause overheating etc etc.
This is an off the cuff fast suggestion.

 

[lums]

My boiler is exactly the same.

In morning first thing water seems fine.

No heating on all day, water is cold!!
Turn on heating then water, heating goes off, try a few times eventually it works. Then stops working again.

Heating is fine water is not.

Any ideas welcome?