Goodman mini-split indoor unit shows E2 and cooling stops intermittently

Safety first: Turn off power to the indoor unit at the breaker. Use a non-contact tester to verify power is off before removing covers.

Steps to check:

• 1. Access the indoor coil: Remove the front cover and filter from the Goodman mini-split. Remove the small panel covering the control area to access the thermistor wiring.
• 2. Locate the evaporator thermistor: It is usually clipped to the evaporator coil tubing near the center or return-air side, with two small wires leading back to the PCB.
• 3. Check connection: Follow the thermistor wires to the indoor PCB. Ensure the plug is fully seated and not corroded or damaged.
• 4. Inspect sensor placement: Confirm the thermistor is firmly clipped to the coil surface. If it has fallen off, reattach it securely so it senses coil temperature correctly.
• 5. Test or replace thermistor: If you have a multimeter and the Goodman service manual, you can check thermistor resistance vs. temperature. If readings are far off spec, replace the evaporator thermistor with a compatible Goodman part.

When to call a professional: If a new thermistor does not clear E2, the indoor PCB may be defective and should be diagnosed and replaced by a technician.