i have a gas, hot water system that uses radiodors, circulator and expansion tank, i guess its a standard type of system. the boiler is in the basement, there are two additional floors above, each floor has two units, with a total of 6 units with six heating zones. i'm having a weird problem, i have heat going to the top floor two units, 1st floor two units are also ok, the problem is the two basement units, the heat is not circulating to the bottom two units. i checked the zone valves and the electrical power to them, this seems ok, i also get no circulation to these units when the zone valve is set to open, i know the zone valve is not stuck because i can open the system to bleed out the air. So i've also blead the system, each unit individually, i did this for the second time yesterday using a bucked which a friends suggested, although it took longer i could see the bubbles better, i did also notice the water being almost black with a lot tiny black particles, i guess this is soot from the boiler, is this normal? So it seems like i still have air in the system, what could be causing the air to enter the system, and why would the bottom two units not get circulation and the top floors are ok, thanks in advance.
- posted
17 years ago