AIR IN SYSTEM

[alexbetts]

HI

I HAVE A LOT OF AIR IN THE SYSTEM (RADS) EVERY TIME WE BLEED THEM 5 MIN LATER THEY NEED IT AGAIN. THE SYSTEM IS A GRAVITY fed CENTRAL HEATING THERE IS NO 2 OR 3 PORT VALVES AND RUNS OFF AN IDEAL MEXICO 2. when the heating is on the hot water is on but that is down to who ever installed it approx 30 years ago. the system is balanced.

We have checked for leaks but found none.

any ideas

 

[tommyl18]

if air keeps coming back it could be gas from corrosion off the rads if there is no inhibitor in the system

 

[stiler]

Sounds like your system needs a flush and as above some inhibitor added.

You could also try fitting some auto-bleed valves to your radiators
http://www.nlbengineering.co.uk/
£5 from PTS.

I would also fit a Spirotech Spirovent domestic Deaerator
http://www.spirotech.co.uk/en/products/

It's up to you if you want to fit a a Spirotrap Dirt separator at the same time or even the combined Deaerator & Dirt separator but it would help maintain your system at it's best. There are some that don't recommend inhibitor when using a Spirovent/Spirotrap and I have to be honest I don't have any in my system but then again my whole system is non ferrous inc my rads.

 

[alexbetts]

Hi

Thanks for the quick replies but the system has been flushed, Radiator changed. TRV fitted (Bi directional) to Rads and inhibitor added. there is still a lot of air i think it could be bled every 15min.

Gravity fed, ideal mexico 2 pumped system the system is very old but the boiler work like new

Any more help would be appreciated.