Carrier Comfort Zone 2 flashing E2

The e2 error on your thermostat is a problem with the return temp sensor on your system, the only thing you can really do is call a company and replace it, you can't bypass it or remove it cause the system wont run properly

My Carrier guy said that E2 means a low voltage problem. He also said that E1 means a high voltage problem, but also threw in the comment that without high voltage there would be no low voltage either, so it could read E2. In my case, the evaporator is up in the attic and there is a float shutoff switch that shuts the unit off when the drain is stopped up and water backs up into the pan--so that the water doesn't run down onto the sheetrock on the ceiling. So the shutoff switch cuts off the low voltage and E2 shows on the thermostat. Clean out the drain and the water doesn't back up into the pan any longer.

E-2 was flashing on my Carrier thermostat and sometimes it maybe caused by a boken return temperature sensor but this time it was a burned out pump motor on the side of my unit downstairs that pumps out the condensation. Good Luck.

Due to thermister fault this problem occurs. if not go for pcb replacement.

Our zone 2 heater was not turning on, and E2 was flashing on the thermostat. We solved the problem by changing the batteries in the thermostat.