Adding a rad to a combi boiler system

[Richard Markham]

I want to add a new radiator to my combi boilered system.

To drain a combi system, is there anything special i need to know?

Is it just a case of turning off the boiler and draining?

Is refilling straight forward too?

Cheers,

[Scott Mills]

Yes. turn off the bolier. drain through a radiator valve or better still the bleed pipe if you can find it (maybe in teh bathroom)

Do not drain using the 4bar break valve on the bolier. You'll break it.

To refil, I do the following:

1. Sit the misses in front of the old bolier (not her mother) and explain to her how the filling loop works and the pressure gauge.

1. Get her to fill it while I run around bleading the rads in turn.

2. When the pressure hits 1.5 bar on the gauge she stops filling. I bleed the rads (pressure will return to zero)

1. When I can't bleed anymore misses starts filling again.

2. Repeat steps 2 to 4 until done.

[BigWallop]

If you bleed the system until the guage goes back to zero, then you're not allow the water to blow into the system properly. Best to over fill the system up to around the 2 to 2.5bar level, then bleed down to 1.5bar. This way the water is easily going to get to the top most parts of the system. If the tops of the radiators are below the boiler, then dropping the system to zero is literally emptying the boiler again.