Hot water heat clanging – air?
Hi all,
I recently moved into a new house and have a hot water/baseboard heating system. There is a terrible clanging when the heat turns on. It seems to be eminating from one of the Flo-check valves – as far as I can tell just the one, not both. Someone told me this is probably air in the pipes and we noticed the vent over the expansion tank is shot (see attached picture). We looked but did not see any bleed valves on the upstairs baseboards – I understand these aren’t always installed (unfortunately).
I’m looking for opinions on whether air or something else (flo-check problem?) is likely the problem and looking for suggestions on what should be done. Is it worth draining the whole system during the winter and replacing some of these parts or should I just stick it out? (How big a job is draining the system… how long is the heat likely to be out? We’re in a 2200 sq ft house.) Is there any other way to bleed air?
Thanks for any input,
-Pete
Replies
Pete,
The device that the expansion tank is attached to is an air separator and the device on top of that is an air vent. In a closed system, this is the primary means of removing air form the system. Good practice includes manual vents at high points and drains at low points. But, unfortunately as you understand, good practice is not always followed. If the vent on the air separator is operable, open it up a little when there is a call for heat and water is flowing and see if air comes out. If air comes out keep it open until water comes out. If it doesn't work get it replaced. If it were my house, just based on that photo, I would do some long overdue maintenance, including replacing components that are showing a lot of corrosion and/or neglect. If it is heating season and its working, wait until a more opportune time, then take it down and do it right.
Edited 2/8/2005 9:26 am ET by Timbo
It looks from here like your air scoop (above expansion tank) might be shot, like you are suspecting already.
I cannot see it, but if your circulator is on the the return side, you will likely have chronic air problems.