E1 can mean thermistor, but can also mean you didn't reconnect the 8-pin plastic connector/wire harness (not the ribbon cables) to the control panel that runs from front (where ribbon cables connect to it) to back (where power supply comes in) along the left side of the machine. Between the power supply cables, the ribbon cables, and the front panel and back cover, there's a lot of tension on the metal cover for this electronic panel. When removing it, the electronic connections can disconnect before you get a chance to do it, and you might not notice the wire harness w/8-pin connector coming up from the front left of the unit. Fail to reconnect it and you'll still get an E1 error, but the thermistor (especially if you've already replaced it) isn't likely the problem. BTW, you can replace the thermistor without removing anything more than the lower front cover. It's fairly accessible right behind the lint trap to blower cover. Please, please, please turn off circuit breaker and unplug the unit first.