There’s definitely a change needed in the firmware. My guess is that the Wyze thermostat is adding some sort of default safety program to avoid furnace over temp by turning on the fan prior to heat. However, those things typically built in to furnaces already and it’s wasting energy at best. or at worst, creating a conflict with the furnace control or triggering a fault.
Different HVAC units vary, buy my oil fired hot air furnace’s built in way of operating is:
- Furnace lights and gets up to temp without blower
- Once furnace is up to temp, blower turns on
- When house reaches set temp, flame shuts off.
- Blower continues for a short time then shuts off (less than a minute)
- After around a minute, the blower turns on for maybe 30 seconds to purge residual heat
Then all remains off until thermostat calls for heat and the above cycle starts over.
Having schedules, the ability to operate the fan independently, Home/away, Alexa, etc are great things. However, a thermostat shouldn’t ever add any steps to normal operations like calling for heat. Once the thermostat asks for heat or AC, it should just trigger the operation and leave the steps to the furnace/AC.