Air Lock

[emergencyman]

Hi all, I drained down a system to repair a rad valve. Its a 2" one pipe system. On the ground floor there are about 20 cast radiators, on the second floor about 20 radiators and in the basement there is the boiler and underfloor heating. It has two system boilers( although only one working) which are about 5 years old, the rads and pipework are at least 50 years old. It is fed from a header tank on the top floor. I refilled the system and now 5 rads on the top floor are not working, they all appear to branch off the same 2" pipe which then rises to the top floor, but I cannot see any air vents. Any ideas for getting them working? I am thinking of connecting cold mains to the drain off in the basement , any other ideas. ( sorry for bad punctuation, but for some reason the return on my keyboard does not work on this forum) Thanks.

 

[Whn1]

Have you tried shutting the other rads down apart from the ones on that run? Maybe do that and up the pump speed to clear it. If no luck then I'd be looking at a mains fill or disconnect the rad at the end of that run and stick a Vax on it.

 

[on31ll]

As above for starters turn rads that are working off and try and force the water to the cold non working rads and look harder for a air vent ! If really cant find one then fit one because you need to get that air out !

 

[emergencyman]

Thanks. When I originally refilled I ran out of time as they shut at 6 so on Friday have a full day on it. Fitting an air vent really would be a last resort as its old rusty 2" iron pipework that is best left alone if possible. The top floor has had some work done so wouldn't surprise me if the air vent isn't now boxed in so will have a good look. I really must stick to 22mm copper max in future:cheesy:

 

[on31ll]

It will have somthing to vent the system on it somwhere !