[KKfromNJ]

We have hot water baseboard, 1 circulator, 2 zone valves, 2 thermostats (1st flr, 2nd flr), Honeywell. Last week 1st flr heat stopped working. Forecasted to be cold in a couple of days, need to fix this. I think it's the powerhead on the 1st floor zone valve but need to make sure before I buy one.

With the furnace warm, if I manually open the 1st flr zone valve we get heat to the 1st flr.

If the furnace is cold and the 2nd flr stat is NOT calling for heat, if I turn the 1st flr stat all the way up the furnace DOES NOT come on. I thought this might point to a bad stat but if I cross the 1st flr stat wires the furnace still does not come on.

Thanks for any Help

[hvac1000]

If you turn on the first floor T-stat does the pump run?


((With the furnace warm, if I manually open the 1st flr zone valve we get heat to the 1st flr.))

If you open the first floor valvae manually does the heat come on when boiler cold?

[KKfromNJ]

Thanks for your help.

The only time the furnace fires and/or the pump comes on is when the 2nd floor stat is calling for heat

[KKfromNJ]

Funny thing (to me) is when I was checking the 1st flr stat, turning all the way on and off, I expected to see the little spark in the merc capsule but didn't. When I shorted the 1st flr stat wires I saw no spark.

[hvac1000]

It could be the power supply for the first floor area. Transformer I suspect. Get out the volt meter and start back tracking to find the problem.

[KKfromNJ]

There is only 1 transformer

[hvac1000]

You still need to trace back to find what happened to the signal from the first floor.

[KKfromNJ]

I changed the power head, all is GOOD! Thanks to everyone for their comments.