My AE has been acting up. It would show low battery icon, and go to sshigh, even tho I didn't have a battery hooked up to it. The wall screen would show a list of error codes. After all this it would go back to manual high. But I couldn't get up to temp. Luckily I have an older 330C control board I installed this afternoon around 3. Been running fine ever since. Pays to have spare parts. kap