Expose Heat Source Control (Heat Pump vs. Gas) via API/Matter for Time-of-Use Rate Optimization

[jgolliher]

I am interested in controlling the heat source of a dual-fuel heat source via the Google Home API and/or Matter. This would be incredibly useful for optimizing costs based on utility pricing.  

Current Limitations

I have a Google Nest Thermostat (4th Gen) controlling a dual-fuel system (Heat Pump + Gas Furnace). The current control mechanism in Google is limited to a fixed outdoor (crossover) temperature.

This fixed setting fails to account for Time-of-Use (TOU) electricity rates. My utility charges rates that are up to 3x higher during peak hours (e.g., 5am - 11am). During these peak windows, the gas furnace is significantly more economical than the heat pump, even if the outdoor temperature is above the crossover temperature.

The goal is too programmatically force the system to use the gas furnace (aux. heat) exclusively during peak electricity cost hours, and revert to the heat pump (primary heat) during off-peak hours.

The Competition

The capability is available on competing platforms. Ecobee's API exposes the hvacMode parameter, which allows users to control the heat source. 

[DeboraJ]

Hi @jgolliher,

Thanks for reaching out to the community! I understand that you are wondering about controlling the heat source of your dual-fuel system using your Google Home app. Thanks for providing the current heat source that you have! Let me help you with some information.

For the function that you are looking to use, there is a feature called Heat Pump Balance. This option will help you control your dual-fuel system and optimize the costs that you mentioned. To use this, please follow these steps:

• Open the Google Home app.
• Tap Favorites or Devices.
• Select your thermostat.
• Tap Settings > Thermostat > Heat Pump Balance.
• Select a Heat Pump Balance setting (e.g., "Max Savings").

I hope this helps!

Best regards, 

Debora

[jgolliher]

Thanks! I did not see Heat Pump Balance under my thermostat settings. I found this article which says it's available for systems with auxiliary heat. I wonder if it's not available for dual fuel systems, which technically have aux heat but are treated slightly different by the thermostat. 

Either way, the ultimate desire is to actually control which heat source is used based on the time of day. It doesn't seem possible to do that but would be a nice feature to match Ecobee functionality.