quick bit of help bleeding central heating system

[drives]

Hi, was after some help bleeding my central heating system if possible?

Firstly I'm a real ameuter at this kind of stuff so please bear with me (i've read the FAQs above but still a little confused)...I'm presuming I have a vented system as I have a cold water tank in the loft, a boiler in the downstairs kitchen and a hot water cylinder in the airing cupboard upstairs.

When my central heating pump first starts up theres a gurgling sound for a few seconds so there presumably is some air trapped in the system. I've bled all the upstairs radiators but its still making the noise.

Therefore I've had a look in the airing cupboard for another bleed valve near to the pump/cylinder. I've taken some photos and would really appreciate someone pointing me in the right direction:

Plus theres what looks like a valve on the pipe going into the cylinder near to the bottom, level with the pump....

In this system what do I need to loosen to get the air out? Would it be the screw in the pump or another valve? Plus how does the system need to be set when doing this?

Thanks in advance

 

[ianniann]

The big screw on the front of the pump can be removed to vent the pump. Warning, water will come out!

Gurgling may not be trapped air. Where does the noise seem to come from? The pump? A particular radiator? Does the system work OK? All the radiators heat up fairly promptly?

 

[drives]

Thanks, I take it the system needs to be off when undoing the screw? Also the noise comes from the pump and everything heats up fine....

 

[Red_Man]

Get a flat headed screw driver and some kitchen roll... slowly unscrew the front of the pump and listen for bleeding.

Also, the second picture is a bleed. slowly unscrew it, and again, have kitchen toll at hand as water will come out.