Thermostats discovered, but fan mode and temperature setpoint writes fail on multiple devices

[wkasperski1-byte]

Thermostats are discovered, but fan mode and temperature setpoint write commands do not work

I am experiencing partial thermostat control failures with the Alarm.com Home Assistant integration.

The integration successfully discovers my thermostats and reads their status, and HVAC mode changes work correctly. However, fan mode and temperature setpoint write commands do not.

Environment

• Home Assistant OS
• Alarm.com integration: v4.0.1-beta.2
• Two Alarm.com-connected thermostats
• Official Alarm.com mobile app controls both thermostats correctly

Working

• ✅ Thermostats are discovered
• ✅ Current temperature updates correctly
• ✅ Target temperature is read correctly
• ✅ Fan mode is read correctly
• ✅ HVAC mode (Heat/Cool/Auto/Off) can be changed from Home Assistant

Not Working

• ❌ Changing the target temperature from Home Assistant has no effect
• ❌ climate.set_temperature has no effect
• ❌ Changing the fan mode has no effect
• ❌ climate.set_fan_mode has no effect

The thermostat never changes, and the Alarm.com app also shows no change after these commands are sent.

Testing Performed

I tested approximately 15 different versions of the integration.

• Current 4.x versions discover the thermostats correctly but cannot change fan mode or temperature setpoint.
• As I downgraded to older versions, thermostat support became progressively worse.
• Some older versions did not discover the thermostats at all.
• I was unable to find a version where thermostat discovery, fan control, and temperature control all worked correctly.

The exact same behavior occurs on two different thermostats, making a device-specific issue unlikely.

Steps to Reproduce

1. Install v4.0.1-beta.2
2. Configure the Alarm.com integration
3. Open a thermostat entity
4. Change the HVAC mode (works)
5. Change the target temperature (no effect)
6. Change the fan mode (no effect)

Expected Behavior

HVAC mode, temperature setpoint, and fan mode should all be writable from Home Assistant.

Actual Behavior

Only HVAC mode changes are successful. Fan mode and temperature setpoint write commands have no effect.

Additional Information

One of my primary goals is to use Home Assistant for intelligent HVAC circulation based on Alarm.com window sensors, indoor air quality, weather conditions, and scheduling. Fan mode control is essential for these automations.

I'm happy to provide debug logs, diagnostics, thermostat model information, or perform additional testing if it would help identify the issue.

[wkasperski1-byte]

I realize this is an open-source project and that you may have limited time. This thermostat issue is central to my Home Assistant deployment, so I wanted to ask whether you accept sponsored development, paid troubleshooting, or a bug bounty for a narrowly scoped fix.

I can provide sanitized debug logs, diagnostics, thermostat model information, browser network captures from working Alarm.com fan and setpoint commands, and perform testing on two affected thermostats.

Please let me know whether paid investigation is something you would consider, or whether another contributor familiar with this integration might be interested.

[wkasperski1-byte]

I can confirm that switching to the Bonasort fork, version 3.0.14.5, fixed the problem. Home Assistant can now successfully change the thermostat fan mode, and the physical thermostat and blower respond correctly. Thank you, Perry, for sharing the solution!