Biasi Combi Boiler

[psynegy]

Hi,

I've been trying to find some information on how to drain my central heating system, it's a Biasi Combi Boiler (Model: M90F 28S).

My main concern is not knowing what the different pipes coming in and out of the system are, photo attached.

Untitled

• psynegy
• 8 Mar 2009
• 1

Really all I want to do is flush out the stuff that is in there and give it a cycle.

 

[keego]

From left to right.
CH Flow, hot, gas, cold main,CH return.

 

[psynegy]

In terms of pressure in the CH system, when I bleed a radiator, should there be a dribble of water, or a fair amount?

 

[gas4you]

Depends what pressure the system is pressurised to and whether the rad is upstairs or downstairs if the pressure is low.

 

[psynegy]

It's pressurised to about 2bar according to the boiler dial. The radiator I was testing was one floor above.

 

[gas4you]

Then when you bleed the rad the air/water should come out quite fast.