Air in central heating system!

[baronwills]

Hi folks, hope you can help.

Going round to a customer tomorrow who says that every few weeks he bleeds his radiators and all the upstairs rads are full of air so he has to keep topping up the system. The boiler is in the garage, a 2yr old Worcester combi.

Not sure where to start looking so any advice would be gratefully recieved.

 

[Simon F]

first check is it "air" or hydrogen which will burn as you bleed the rad ( if you light it! )
that would indicate excessive corrosion taking place.
check pipe work set up of fill and vent, height over f+e

just noticed its a combi, most likely never flushed out properly, corrosion

 

[M.Joshi]

When was the system last drained/flushed through? Has inhibitor been added recently? Has the customer been filling the system without topping up the inhibitor? Fragments from inside the radiators could be reacting with other metals resulting in iron oxide in the system causing the air to build-up. Have a look at this link for a better description:

Radiator Troubleshooting - A L Plumbing And Heating

 

[baronwills]

Thanks for the help Gents.