Air in the system

[mrlennie]

There is air getting in a customers system and I can't figure out what it could be. He has to bleed rads once every week or two.

They called a plumber ages ago and he seems to have fitted a check valve?! on the open vent pipe and he seemed to think this would cure it. Customer says still same problem. (as far as i know there shouldn't be anything on the pipe) I've checked for small leaks that would draw air in and we are going to look at the position of the pump but it's one of those things it could be anything.

What do you think?

 

[diesel_ltd]

have you checked for leaks? does down stairs heating pipes run under the floor wooden or scread??

 

[mrlennie]

Yeah checked everywhere there is screed so i will tie up the ball valve for a while and see if the level drops.

Just seen a thread about the pump being on the wrong side of the system, what do you think? and also is it ok to leave the check valve on the vent pipe?

 

[crashndie]

is it a combined cold feed ? get rid of the check valve asap should never have anything on the open vent not even a gate valve ! is the pump on the return of the system or on the flow? what condition is the water in the system? could be hydrogen from sluge thats being vented off unlikely it would create so much so often tho. is the any auto air vents any were?

 

[ecowarm]

possibly cold feed / vent wrong way round or wrong position sucking in air or pumping over