Hoping someone here does this for a living or has been through this and can confirm my suspicions.
Situation: Hydronic (baseboard water) heating system, 2 zones plus an indirect tank for domestic hot water, so 3 Taco 555-102 valves. House built in 1995, everything is original, oil-fired Smith boiler serviced every year. Single Taco 006-B4 circulator. Honeywell L8124A boiler controller, pretty simple.
Issue: discovered the other day that zone 2 (upstairs) won't get any heat when the thermostat calls for it. If I manually open the Taco valve with the lever (very stiff), heat flows. Checked voltages, it is getting 24V AC when the system calls for heat, it just seems the valve isn't opening.
I also realized that the circulator is running all the time, 24/7/365. It's so quiet that I never heard it, but now that I think about it, I don't ever recall the system not making that hummmm when it's switched on. Doesn't seem right.
I chased all the wires, and it appears to be hooked up correctly. If I disconnect the (green) wire from the #3 terminal on the #2 zone valve, the circulator stops running. Doesn't matter if the zone is calling for heat or not. If I hook it back up, and disconnect any of the other #3 terminals, the circulator keeps running. Meter tells me there is a short between terminals #2 and 3 on the #2 valve, but not the case with the other 2 valves (when they are closed).
So... my YouTube training and Googling tells me that the Taco power head has failed, that it is not opening the valve AND there is a short across the #2 and 3 terminals that is causing the pump to run all the time.
Make sense? I just want to be sure before I go plunk down ~$100 for a new power head. Or could the entire valve need replacing?
Situation: Hydronic (baseboard water) heating system, 2 zones plus an indirect tank for domestic hot water, so 3 Taco 555-102 valves. House built in 1995, everything is original, oil-fired Smith boiler serviced every year. Single Taco 006-B4 circulator. Honeywell L8124A boiler controller, pretty simple.
Issue: discovered the other day that zone 2 (upstairs) won't get any heat when the thermostat calls for it. If I manually open the Taco valve with the lever (very stiff), heat flows. Checked voltages, it is getting 24V AC when the system calls for heat, it just seems the valve isn't opening.
I also realized that the circulator is running all the time, 24/7/365. It's so quiet that I never heard it, but now that I think about it, I don't ever recall the system not making that hummmm when it's switched on. Doesn't seem right.
I chased all the wires, and it appears to be hooked up correctly. If I disconnect the (green) wire from the #3 terminal on the #2 zone valve, the circulator stops running. Doesn't matter if the zone is calling for heat or not. If I hook it back up, and disconnect any of the other #3 terminals, the circulator keeps running. Meter tells me there is a short between terminals #2 and 3 on the #2 valve, but not the case with the other 2 valves (when they are closed).
So... my YouTube training and Googling tells me that the Taco power head has failed, that it is not opening the valve AND there is a short across the #2 and 3 terminals that is causing the pump to run all the time.
Make sense? I just want to be sure before I go plunk down ~$100 for a new power head. Or could the entire valve need replacing?