Listen and log HVAC work status with an older phone, Read reports in your newer devices. Notes and images can be attached to provide customized information. Reports and notes are accessible within your home network only.
0 technical requirement, 0 wiring, 0 cost.
Note: You only need to install this App on your older sentry phone, and run it near your HVAC. No extra installation, registration or whatever is needed on other devices.