Got a problem with our CH system. There's loads of air getting into the system such that the upstairs radiators need to be bled every other week. Now I can't find any sign of a leak anywhere so I don't think it's a leak. There is inhibitor in the system - it was put in at the beginning of the year when the one of the valves was replaced (had a problem where no hot water but CH worked which led to the valve being replaced and the system being flushed). Since the replacement of the valve nothing has been done to the system, not even turning it off, and it worked without problems immeidately after.

Any ideas? Even if it is obviously a leak, just let me know and I'll look harder for it.

But that doesn't solve the probem HM.

Suspect the system is out of balance, blocked cold feed, valve fitted wrong, pump on the wrong setting.

more info on type of system required.

scruff

[quote author=thescruff  link=1102617868/0#2 date=1102630057]Suspect the system is out of balance, [/quote]

Nope, no rad valve has been touched in three years

Quote:


possibly, but once bled the system fills again so there is water getting into the system from the cold water tank.

Quote:


Possibly, but it was working properly immediately after it was replaced at the begining of the year.

Quote:


Possibly since the motor might have been fiddled with when the valve was changed, but the system had no bleeding problem (sorry about the swearing!  ) immediately after the valve replacement and none till 2 months ago.

Quote:


It's a condensing boiler feeding the CH system. Not a combi boiler since the hot water is stored in a hot water tank. No TRVs on the rads. The pump's setting is set to 2. Pump is a Grundfos Selectric UPS 15-50. Anything else you need to know, let me know.