Bleeding Radiators

[BigDogsWang]

Do I bleed them when the heating is on or off? Which rad should I start with first?

[kwicky]

http://www.diydata.com/problem/central_heating /bleed.htm

[pilotlight]

Radiators should always be bled when the pump / heating is off. This eliminates any chance of the pump sucking air into the system.
Start wherever you wish.
Hope this helps.

[BigDogsWang]

Thanks guys

[Nether Edge]

As hot air rises, highest radiator will have most air.
Feel each (when heat is on) to determine where air collects most. That must therefore be highest in house.
Once heat is off, I'd then start with lowest ones then work upwards.

[BigDogsWang]

All done. It's a three storey house. The ones on the first two floors were OK, but the two rads on the top floor were absolutely full of air.