Thermostat displays E14 and may not control the humidifier; indoor humidity remains low despite calls for humidity.

Safety first: Turn off power to the furnace and humidifier. Shut off the water supply to the humidifier before opening any water lines.

• Step 1 – Confirm humidifier settings: In the thermostat menu, verify the correct humidifier type (bypass or fan-powered) is selected.
• Step 2 – Inspect HUM wiring: At the thermostat and furnace control board, ensure the HUM wire is secure and correctly connected to the humidifier relay or solenoid.
• Step 3 – Check water supply: Verify the saddle valve or shutoff feeding the humidifier is open and that the water line is not kinked or clogged.
• Step 4 – Test solenoid (advanced): With power on and a call for humidity, use a multimeter to check for 24 VAC at the humidifier solenoid. If voltage is present but no water flows, the solenoid is likely failed and should be replaced.
• Step 5 – Clear scale buildup: Inspect the humidifier pad and orifice for mineral buildup. Clean or replace the pad and clear any obstructions.
• When to call a pro: If you are not comfortable working with water and electrical connections, have a Carrier technician service the humidifier.