I have 3 zones with 2 circulators. One circulator serves 2 Honeywell V8043E1012 valves. One valve serves the second floor of my home and may not be working correctly because there seems to be very poor hot water flow through the baseboards (it's cold!). I suspect the valve's power head may be the problem, the round parts that is stamped "Synchronous" is always very hot to the touch (the other power head is not). Does this mean the power head is or could be bad and needs to be replaced ? I read that the power head may not be sending the signal to the circular to turn on. Should I spend the $70 to buy and replace the power head ? I also read I could have a bad transformer, could this instead cause the problem ? Remember the OTHER valve works fine and gets good flow from the same circulator. I thank you in advance for any help you can provide.

Geomac

Here is the manual for the valve: http://customer.honeywell.com/techlit/pdf/95c-00000s/95C-10932.pdf

You should try to operate the valve manually. (instructions in the above document)

The thing marked "synchronous" is a synchonous motor. It's continually running, so that's why it's hot. It may not have enough torque to turn the valve, because the valve is bad so this is why manual operation should be attempted.

If it's shimmering, then the capacitor for the motor is likely bad.

I have the same problem, Have 2 other zones that work but this valve does not open and have to move it manually, When the therm calls for hear, I can hear the valve click and watch it try to open. Does this mean the motor is bad? It also doesn't signal the pump to run. Any advise?