how can i let air out?

What type of central heating system have you got? if its pressurized then you can bleed rads and add pressure using filling loop to about 1.5 bar max-using pressure gauge on front of boiler. if its a conventional system you can bleed rads of air and the expansion tank in the loft will add water automatically. But why have you got air in your boiler? Could mean a fault somewhere.

daz71
November 2008

you have to bleed the radiators using the little keys on the end of each radiator. Be careful though, only open them a little bit until the hissing stops and drops of water start to come out. You will have to top up the water in your boiler using the filler loop (usually a silver pipe with a little tap on it; you should fill it up until the pressure gauge reads about 1 bar) you will need to go round the house bleeding all the radiators.

Stig
November 2008