Hello- I have a 3 zone oil-burner and hot water baseboard radiators. One of the zones does not heat. I tried turning up the thermostat to 90 and leaving it that way for about 10 minutes- nothing. All three zones have Taco 571 zone valves. On the zone in question I moved the switch on the Taco box to "open" and left it that way for about 10 minutes- nothing.
Does that indicate a bad zone valve switch?
I don't know much about it- so any help much appreciated.
There should be a small air bleed petcock/screw on the top/end of the radiators for that area. Open it slowly and bleed the air out until water comes out. You should also get a heating tech to check the water level in the system/expansion tank etc etc once a year.
All the radiators appear to be the same. Copper pipe out of the wall and into some metal fins and then copper pipe out and back into the wall. I don't see any kind of bleeder valve anywhere- just pipe and fins. ???