sens i touch keeps saying 'equipment running' but my heat or ac isn't actually on, the app just shows it running forever

Diagnosis

The "Equipment Running" status on the Sensi Touch ST75 is a software-state mismatch caused by the thermostat's internal logic believing a circuit is closed when the actual HVAC hardware is idle. This typically happens when the thermostat sends a signal to the Y (Cooling) or W (Heating) terminals, but the return signal or the internal relay state fails to reset, leaving the app in a "pending" state. This is often caused by a "ghost" voltage leak or a configuration mismatch during the initial setup where the ST75 is expecting a specific type of heat pump or multi-stage system that isn't present. If you have a C-wire (Common wire) that is intermittently losing connection, the thermostat may trigger a call for heat/air, lose power for a millisecond, and then reboot into a state where it believes the equipment is still active because the internal relay didn't cycle off properly. You can confirm this by checking if the HVAC blower is actually moving air; if the app says "Running" but the vents are silent, the issue is strictly communication between the ST75 logic board and your furnace/AC control board.

How to Fix It

To resolve the state mismatch, you must force the ST75 to re-verify the electrical load on each terminal. This clears the cached equipment state and recalibrates the voltage detection.

1. Approach the Sensi Touch screen and tap the Menu icon in the bottom corner.
2. Navigate to Installation & Wiring and select Equipment.
3. Select Reconfigure Equipment. This will trigger the system's internal diagnostic mode.
4. The thermostat will now perform a sequential test of the Y, G, W, and O/B wires. You should hear the HVAC system clicking on and off during this process.
5. When prompted, confirm the type of heating (Electric, Gas, or Heat Pump) and the number of stages. Ensure you select "Single Stage" unless you specifically have a high-efficiency multi-stage unit.
6. Once the wizard completes, tap Finish.
7. Perform a "Hard Power Cycle": Turn off the breaker to your HVAC system for exactly 60 seconds, then flip it back on. This forces the ST75 to clear its volatile memory and sync its current state with the actual equipment status.

If That Didn't Work

• Inspect the C-Wire Connection: Ensure the blue or black C-wire is securely seated in the C terminal. If the wire is loose, the ST75 may experience "power cycling" where it sends a signal to the equipment but loses power before it can register the "off" command, leaving the app stuck on "Running." Tighten the terminal screw or replace the wire if it is frayed.
• Check for "Short Cycling" Protection: The ST75 has built-in compressor protection. If the system was turned on and off rapidly, the thermostat may display "Equipment Running" while it is actually in a 5-minute lockout period to protect your AC compressor. Wait 10 full minutes without touching the app to see if the status resets.
• Verify the G-Wire (Fan) Configuration: If your fan is set to "On" instead of "Auto," the app will report "Equipment Running" because the blower motor is active, even if the AC or Heat is not. Go to Menu > Settings > Fan and ensure it is set to Auto.
• Test for a Stuck Relay: Go to your furnace/air handler and locate the control board. Carefully check if the relay for the specific stage (e.g., the Y terminal) is physically stuck in the closed position. If the board is sending power to the AC unit even when the thermostat is off, the issue is a failed relay on the HVAC board, not the Sensi Touch.

Heads Up

• Avoid using "Jumper Wires" between the R and Rc terminals unless specifically required by your system; the ST75 handles power bridging internally, and external jumpers can cause erratic status reporting.
• Always ensure your HVAC filter is changed every 30-90 days. A clogged filter can cause the system to overheat and trip a limit switch, which cuts power to the equipment while the thermostat still thinks it is "Running."
• If you are using a C-wire adapter (Power Extender Kit) instead of a dedicated wire, ensure the adapter is mounted securely inside the furnace cabinet to prevent signal noise that can confuse the ST75 logic.