refilling a central heating system

[cherryb]

Hi

just a quick one, going to add an extra rad to the conservatory. got a rad in the dinning room with a drop from up stairs. so going to drain ssystem from there. Add pipe work and then refil. this is the bit I would like some advice on going to refil at the combi. do you just open the fill loop then bleed the system down stair first then upstairs then close the filler loop?

all advice welcome, O yes will be adding fernox inhibitor to the system.

Also what size rad for a room 6 metres by 4 metre please anyone

cheers

[sonray ltd]

depends is the conseratory part of the dining room or has it got seterate wall and doors to gain access ?
how do you know the drop downs are not already on their btu limit.

[cherryb]

pipe work is going through a wall into the conservatory. there is only one rad on the drop down in the dining room which I am working from size is approx 500 X 600 ....

[sonray ltd]

and how may does that 15mm branch feed upstairs, by quess 1 at the most.

if this conseratory is totally seperate from your dinning room as in not open plan but with seperate doors etc and was built as a conseratory not a extension then different heating rules apply

[cherryb]

its more of an extension than a conservatory , but thats how the wife calls it. Yep feeds of one rad upstairs, and its 10mm micro bore not 15 mm ...

[sonray ltd]

great 10mm even more fun.
i'll work the rad out in a mo

your going to be looking a a good 6000 btu. example 2 x 300 x 1000 doubles one at each end.
and i would be inclinded to have it fed straight from the flow/return on their own.

[cherryb]

cheers for that, just one other thing if you have 5. just the refilling of the system is it as stated open the fill loop then bleed the rads then close the fill loop???

[sonray ltd]

fill the system to about 1.5 bar.
bleed a few rads then check pressure if pressure starts dropping below about 0.8 bar top it up.
then bleed few more rads then when all bled check pressure and fill to 1.5 bar.
then run system.
you may find later it needs just a top up or maybe a rad bled.

don't go above about 1.5 bar or below 0.8 bar.
and get any inhibitor in before refilling.

[dts]

If its 10mm microbore have you not got a manifold off the boiler, in which case its not good practice to run 2 rads off the same point.