Thermostat Dual Fuel Options

It would be nice to have a dual fuel option in which you can set a temperature in which if below that degree your backup hestsource will be used. Currently backup source will be used if the temperature in the house is greater than 10 degrees from what the thermostat is set at.

[Mod Edit]: Title Modified to Enhance Search Clarity.

This is a definite!!!
After installing and going through the process twice, I could not figure out this option. Now finding this I understand that there is no such option.

My heat pump can not work below 35 degree outside temp. Mine is not so different than other Trane models of the same vintage.

PLease tell me this is in work. My first night after install the system ran all night trying to recover from an outside temp of 30 ish.

So I suppose to test that the Aux is getting called I must raise the temp more than 10 degree split?



I don’t think that is considered dual fuel. Sounds like you have a heat pump and a main source of heat. A dual fuel would be like electric heat as a main source and propane as a backup if electric goes in off peak. A heat pump can also be added to this system.

However, I do wish this thermostat could control the heat pump by the the outdoor temp with a user set low temp cutoff point to only use main source of heat. There seems to be no heat pump controls.

I would check outside on your actual heat pump for a manual temp switch. There should be a adjustable one somewhere on it.