Rad fills with air every couple of days.....

[ktlfc]

I have a rad that fills with air every couple of days!! A plumber fitted an automatic valve to the system which helped a small amount... The ait valve is lower than this rad.
Any ideas on why I am getting so much air in this one rad?

Thanks

 

[ChrisR]

Is the air valve an automatic one, in a position where it would collect any air before the rad.?

COmbi or what?.........

 

[croydoncorgi]

Putting in an automatic bleed valve is fixing the symptom, not the problem! If it's venting air all the time, the system will STILL be damaged because oxygen from the air that's STILL getting in somewhere will be dissolving in the water before it gets to the ABV!

Has the system actually been checked for leaks at all the places where it will be at negative pressure when the pump is on? ESPECIALLY the stem gland on the inlet-side pump isolating valve. (If it's a ball-type isolator, opened and closed with a screwdriver, it's probably leaking!)

If the problem has 'always' been there, pipe layout / connections may be wrong.

And if the ABV actually made little difference, check that the 'air' is not in fact hydrogen. When the rad next goes cold, open the bleed screw A LITTLE and try to light the gas. (But don't light the curtains!)

 

[ktlfc]

It's not a combi...

The ABV is on the flow from the cylinder....

I will check that it is air..

I haven't found any leaks (no puddles on the floor or coming through the ceiling)...

 

[Slugbabydotcom]

ESPECIALLY the stem gland on the inlet-side pump isolating valve. (If it's a ball-type isolator, opened and closed with a screwdriver, it's probably leaking!)

Had one similar to this recently on a 25 rad system ... checked the obvious stuff and the culprit was.... the pump, dragging air in through the armature cover I suspect or round there somewhere. Post mortem revealed black magnetite on the inlet but the impeller area was rusty brown indicating ingress of air.