Thermostat shows E7 and system will not energize heating or cooling stages correctly

Safety first: Turn off power to the furnace/air handler and outdoor unit at the breaker before touching any thermostat wiring.

• Step 1 – Verify system configuration: In the thermostat setup menu, confirm the correct system type is selected (e.g., Amana heat pump vs. conventional gas furnace with AC). Incorrect configuration can trigger E7.
• Step 2 – Inspect thermostat wiring at thermostat: Remove the thermostat from the wall and inspect the low-voltage wires on the sub-base. Ensure each conductor is firmly clamped under the correct terminal (R, C, Y1, Y2, W1, W2, G, O/B, etc.). Look for stray wire strands that could cause shorts.
• Step 3 – Inspect wiring at furnace/air handler: At the Amana control board, verify that the same color wires are landed on matching terminals. Tighten any loose screws and correct any miswiring.
• Step 4 – Check for shorts: With power off, gently tug on the thermostat cable along its path to feel for crushed or damaged sections. If the cable is pinched in a wall or at the furnace cabinet, it may be shorting conductors together and should be replaced.
• Step 5 – Test operation: Restore power and test heating and cooling calls. If E7 returns immediately and wiring is correct, the thermostat’s internal output circuitry may be damaged.
• Step 6 – Replace thermostat: Install a new Amana-compatible smart thermostat if internal control outputs are suspected to be faulty.

When to call a professional: If you are not comfortable tracing low-voltage wiring or suspect damage inside walls, contact an HVAC technician.