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.