EWC-ST-2E with Honeywell RTH9580WF

[erwin]

I have installed the new Honeywell RTH9580WF as my zone 1 thermostat, to replace a Robertshaw 9610. I had to run a C-wire from the board and disconnect "B" and "O" (there is no terminal for those on the RTH9580WF). The controller works great in zone 1 but for zone 2 does not open anymore.
If the heating is on (in zone 1) and zone 2 calls for heat I hear the relay click on the thermostat but the damper motor for zone 2 does not engage (keeps closed with red LED on).
Any advice?

Thanks,
Erwin

[Erik W.]

Erwin,

The panel you have is a master slave panel and it requires the zone 1 thermostat to have separate o and b terminals connected to the panel or the zone 2 thermostat will not operate at all.

Erik Wnoroski
EWC Controls, Inc.
385 State Route 33
Englishtown, NJ 07726
800-446-3110 ext 483

[erwin]

Eric thanks for your quick response. It seems from the documentation that the B needs to be 24V when heating is on, O needs to be 24V when cooling is on. Would it work if I bridge "W" and "B" for heat and "Y" and "O" for cool?
Erwin

[Erik W.]

Erwin,

that would only allow the zone 2 stat to operate when the zone one stat was calling for either heat or cool. The terminals require a constant 24 volts on either o or b to operate but you can never have voltage on o and b at the same time.

Erik Wnoroski
EWC Controls, Inc.
385 State Route 33
Englishtown, NJ 07726
800-446-3110 ext 483

[erwin]

Great, thanks for your clarification!

[salina]

Where do the jumpers go and will it impact the other zones?

[Erik W.]

You should not be using any jumpers on the thermostat side of the board.

Erik Wnoroski
EWC Controls, Inc.
385 State Route 33
Englishtown, NJ 07726
800-446-3110 ext 483