“Easy fix and easy troubleshoot. I have a 5 zone boiler and in the past 13 years had to swap out two of these valves. They make it easy to buy and the price is good. 9 out of 10 times if your zone is not getting heat it is a bad zone valve. First check the thermostat, turn it up and check the panel to see if the indicator light goes on, if so then manually open the valve by pulling down the zone valve lever, if your line then gets heat you know there isn't a clog in the line so now you know it is a bad valve. Do not pay a plumber, buy the new valve head, you don't need the entire valve, just the head. Turn boiler electric off. Make note where the wires go, usually 3 wires, remove wires from old valve, do a quarter turn, remove old head and install new head, connect wires, turn boiler back on and your heat will work again. When my new boiler was installed the plumber explained to me that these valves go bad and showed me how to replace them. A plumber will charge you $400 for this easy fix.”
“I lost two zones. Heating did not happen. To troubleshoot: Verify power supply is putting out 20-29VAC. Verify valve body opens (pull down the lever on the installed unit. That lever lets hot water through the system, if the valve is operating). If after 10 minutes, the outgoing and incoming pipe are not hot (and you are sure your pipes are not frozen. If frozen is possible, leave lever down for an hour or until you get heat), you have a valve issue, not a head issue. If it is hot on both sides, you are not opening the valve. Push the lever back up. Set your zone thermostat to an insanely hot setting. Use a voltmeter set on Volts AC (~) take the red lead to 1 (top wire screw on head unit) and black to middle wire screw of head unit. You should get somewhere between 20-29VAC. If you don't, it's your power supply or wires to/from thermostat or thermostat. You can ohm out the thermostat and wires by removing the wires from the head. If you do have voltage, your head is bad. My voltage was bad on two units, but once I replaced the one bad unit, the second unit started working (bad unit shunted the voltage, causing zones not to work that had no issue. My understanding, a bad unit could shunt voltage to ground so bad and long, power supply can burn up.”
