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Hydro Air System

We have a Hydro Air system with 2 separate air handlers, one in the basement for the first floor and one in the attic for the second floor. As the temperature was dropping last few days, I turn on the heat for both the first and second floor and noticed that only the first floor was pumping out the hot air and the second floor was pumping out the cold air. I went up to the attic and noticed that the air handler isn’t getting hot water, pipe was cold. Then I went down to the basement where the oil boiler was and I felt a hot water in the pipe. Apparently the hot water is not getting to the air handler in the attic. Any suggestions? Thank you!

Re: Hydro Air System

Is there a thermostat for the second floor and is it set for heat and is it signaling a zone valve?

Re: Hydro Air System

Yes there is a separate thermostat for the second floor and it is turned on for heat w/ temp set higher than the room temp. One thing I noticed was when I opened the ZT-2 Zone pump controller (Bell and Gossett), I can't get a power on the zone 2 (second floor) wire terminals and LED indicator doesn't light up where as the zone 1 (firt floor) wires have power and lights up. does this sound normal?

Re: Hydro Air System

The good news is there is one zone that is working which will provide assistance for some basic troubleshooting.

You've already had the controller open which means you are probably familiar where the thermostat wires are attached on the circuit board terminal strip.

I'm guessing that the first floor thermostat is wired to #1 terminal and the second floor thermostat wired to #2 terminal.

Since the first floor zone works remove the thermostat wires for #1 ..... be sure to notate and mark which wire goes where before disconnecting .

Do the same for #2 ..... once you have notated and marked the wires attach these in the place for #1.

Turn up the temperature on thermostat #2 .... this should light up the #1 LED and turn on the zone #1 circulator.

If this doesn't ...... this means there is likely a problem with the wiring or the thermostat associated to #2 .

If it does .... there is a problem more likely with the ZT controller.

Don't forget to reattach the #1 and # 2 thermostat wires back to the original locations after you're done with the testing.

If you want to verify the zone #2 circulator ......with the thermostat wires in the correct location ..... disconnect the circulator wires from # 1 and move #2 to that location.

**warning .... be careful since this is 120 volts disconnect power to the ZT controller before doing this.

When thermostat #1 calls for heat #2 circulator should start.

If it doesn't ... there is a problem with the circulator or it's wiring.

Hopefully this makes sense and helps.:)

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