EXPANSION VESSEL - RE-PRESSUREIZE HOW?

Thanks Ian, think I got ya. so once the air has been pumped into the expansion vessel that reading is on the foot/bicycle pump guage and bears no relation to the pressure guage on the front panel of the boiler - thats there purely for the water pressure ?

Martin
January 2010

the drain cock outside is best to use, usually at low level on outside wall, but any drain will do. so long as the pressure you are pumping in has somewhere to go otherwise you will get a false reading on the pressure gauge as you will be increasing the system pressure not the air pressure in the vessel.

Ian
January 2010

Thanks Ian, at the risk of sounding stupid, when u say 'open drain' do you mean drain all the rads and the entire heating system? OR the drain in the base of the boiler unit itself?? sorry .... thanks

Martin
January 2010

heating off, open drain, pump exp vessel to 1 bar, close drain, refill system to 1 - 1.5 bar, bleed pump & rads if req'd, top up pressure if req'd, heating on.

Ian
January 2010