Biasi Boiler not working

[Carron]

Help!

We have a problem with a Biasi M96.24SM/C CH boiler (aprox 7yrs old).

Domestic hot water works fine.

CH side- does not run properly.

IE: CH starts up on its own and then when the temperature reaches 78deg it switches itself back off again. After dropping back down to 68deg (in aprox 1 min) it fires up again. There seems to be no hot water reaching the radiators.

Can the problem be caused by a faulty thermostat or something similar within the boiler?

We have checked the room thermostat and this seems ok.

Any help would be appreciated.

Many Thanks

Carron and Alan

 

[dcawkwell]

Sounds like a blockage in the central heating circuit.

Suggest start by draining and refilling the central heating.

Could be a modulation issue where the burner is only on full or
off.

How does the boiler perform on hot water when there is only a small
demand for hot water?

 

[Carron]

Domestic hot water works as it should with no problems.

We know there is a blockage in one of the downstairs radiators as did this one did not heat up last year.

What do you recommend is the best way to flush the system?

Many Thanks

Carron and Alan

 

[dcawkwell]

Domestic hot water works as it should with no problems.

We know there is a blockage in one of the downstairs radiators as did this one did not heat up last year.

What do you recommend is the best way to flush the system?

Many Thanks

Carron and Alan

Switch boiler off.
Find drain valve and attach hose. Allow water to drain out.
See how the water comes out. Refill with the filling loop until up
to pressure. Run the boiler again.

If you feel up to it. Drain the system and remove each radiator in turn
and flush each radiator out in the garden with a hose pipe.

You can also add a cleaner into the system after you have drained it
and run the central heating around for a week.

You might want to call out a local engineer.

 

[Carron]

Thanks for the advice.

We have tried draining the system but still no luck so looks like we will need to call out the professionals.

Do you know or can recommend anybody that knows this system in our area? We live near Dudley in the West Midlands.

Many Thanks again for your advice,

Carron and Alan

 

[Agile]

I would first be checking the diverter valve!

But you could call Bill Aldred of Design Warm and he will probably send his son.

Tony Glazier