EWC Controls Forum

I have a similar dual fuel system with the same problem. The 2-stage furnace always runs in high stage.

Has there been any change on this issue? I notice there is now a CTK04 thermostat, and I even see a couple of references to a CTK05 thermostat. Will either of these work in a dual-fuel system with the UltraTalk 3000?

The HVAC contractor who installed the system went out of business. The builder ...

I'm having exactly the same problem. Everything works fine except heat calls from the CTK03 on zone 1 don't show up on the UT-3000.