EWC Controls Forum

I see from reading through earlier in the thread that TH4110 series should work with ST series boards. I see from the installation manual for TH4110 that it has all the wire connections needed. The manual seems to think O and B are only for heat pumps - if I just connect the wires, will it work with ...

Hi - I am replacing two old Honeywell Chronotherm III's, with Resideo RTH7560E's, attached to an EWC-ST-2E control board. I replaced Zone 2 (only three wires needed to be changed), and it functioned normally. Then I replaced Zone 1 following Resideo's instructions (they told me it should be ...