hydronic heating

bosrn

Hi guys-
New to these forums but looks like there's a lot of good advice out there.

I bought a house last spring that has 4 zones of hydronic heating. It wasn't winterized properly so there were some burst pipes when we went to fire up the heating system. Disconnected 2 zones in areas of the house that aren't used right now and reconnected basically the upstairs and downstairs after fixing the leaks. Upstairs works great... downstairs doesn't.

It's on a slab and there were parts of the system buried in the concrete and one area in a brick wall that had burst, so I had to bypass these with lengths of PEX that run up through false joists in the ceiling. Everything worked great at first but now I really just can't get downstairs to work. I've bled the system repeatedly. The system has 15lbs PSI in it. The valve seems to operate fine - opens up on the thermostat's command and the circulator pump also kicks on appropriately. I'm at my wits end here - why would upstairs work so well but downstairs not at all???? I would think that if a system were air locked that it would more likely happen upstairs, correct, since air is lighter than water and would move up?? Anything else I can try? I just want to get through these last few weeks of winter and then the downstairs remodel will begin, which will include subfloor radiant heating. Thanks for any advice.

redline

When you ran the new PEX is the line higher than the bled valve?

bosrn

yes...that would make sense i guess... should i add a bleed valve on that part of the system?