Thermostat shows E19 and cannot control whole-home dehumidifier or over-cools for dehumidification

Safety first: Turn off power to the furnace/air handler and any standalone dehumidifier at the breaker before working on wiring.

• Step 1 – Check settings: In the thermostat installer menu, verify dehumidification is enabled only if your Amana system supports it. Confirm the correct control method (overcooling vs. dedicated dehumidifier) is selected.
• Step 2 – Inspect wiring: At the thermostat and Amana control board, verify the dehumidification control wires are on the correct DHUM or dehumidifier terminals and are secure.
• Step 3 – Test dehumidifier manually (advanced): Follow the Amana or dehumidifier manufacturer’s instructions to manually energize the control circuit. If the dehumidifier runs, the thermostat or wiring is suspect.
• Step 4 – Disable feature temporarily: If E19 persists and you do not rely on dehumidification, disable the dehumidification feature in the thermostat to restore normal heating/cooling while awaiting service.

When to call a professional: For integrated dehumidification with Amana equipment, an HVAC technician should verify wiring and configuration.