Heil thermostat or display shows OF or OFF and outdoor unit does not run

Safety first: Turn off power before accessing the air handler or condensate system.

• Step 1 – Verify thermostat mode: Ensure the thermostat is set to COOL and not OFF.
• Step 2 – Check air handler door: Confirm the blower compartment door is fully closed and engaging the safety switch.
• Step 3 – Inspect condensate float switch: Locate the float switch on the drain pan or drain line. If the pan is full of water, clear the drain line with a wet/dry vacuum at the outside termination and flush with water.
• Step 4 – Reset system: After clearing water and ensuring doors are closed, power cycle the system and test cooling.