Joe M Windham , NH May 05, 2017 E3 error code thermistor Purchased part, replaced. This model requires you to lay unit forward to replace this part. Caution: you may want to disconnect the wire that attaches to the pump. Tilting the unit caused strain and damage the wire. 1 People found this story helpful Do-It-Yourself Rating: Repair Time Estimate: Less than 15 minutes