Ecobee ecobee Smart Thermostat Essential with Touchscreen Display and eco+ Smart Features COOL-FAIL Error Fix: Cool Not Reaching Set Temperature

Error code COOL-FAIL on the Ecobee ecobee Smart Thermostat Essential with Touchscreen Display and eco+ Smart Features means: Cool Not Reaching Set Temperature. The thermostat has been calling for cooling but the home temperature is not dropping toward the setpoint — the AC compressor may not be running, refrigerant charge may be low, the air filter may be clogged, or outdoor temperatures may exceed the system capacity

The most successful fix is "Check Compressor Operation and Refrigerant Charge" (medium difficulty, ~90 minutes). Estimated DIY cost: $0-$20. HomeMD has 2 community-ranked fixes for this error.

This error is rated medium severity. It should be addressed soon, but your appliance may still function in a limited capacity.

Yes — the top-ranked community fix ("Check Compressor Operation and Refrigerant Charge") is rated medium difficulty and takes about 90 minutes. Tools needed: T20 Torx screwdriver, HVAC manifold gauge set, Multimeter, PPE gloves and goggles.

DIY cost: $0-$20. Professional repair typically costs $250-$400. Many homeowners save money by trying the top-ranked community fix first.

The Ecobee ecobee Smart Thermostat Essential with Touchscreen Display and eco+ Smart Features has 8 other known error codes, including: APP-SYNC (App and Thermostat Out of Sync), AUX-OUTDOOR (Auxiliary Heat Outdoor Temperature Alert), AUX-RUNTIME (Auxiliary Heat Runtime Alert), BLOWN-FUSE (HVAC Control Board Fuse Blown), FAN-CONSTANT (Fan Running Constantly), and 3 more.

Error code COOL-FAIL also appears on 5 other Ecobee models: ecobee Smart Thermostat Enhanced with Radar Occupancy Sensor and Large Touchscreen, ecobee Smart Thermostat Premium with Siri and Alexa Built-In, Air Quality Monitor, and SmartSensor Included, ecobee SmartThermostat with Voice Control and Alexa Built-In, ecobee3 Lite Smart Thermostat, ecobee4 Smart Thermostat. The fix may vary by model, so check each model's specific page for tailored repair steps.