I have a Trane XE90 and noticed that the thermostat wasn't on. I have two units so I switched the thermostat with the downstairs one (that was working) and it didn't work either. I then checked the furnace control board and it was a slow flash (Normal No Call for Heat). I opened the unit door, which disengaged the switch. When pressed the door switch I could hear a quiet buzzing sound which leads me to believe that there is power to the board. I'm wording if power's going to the thermostat. Oh I also noticed my metal pan underneath my furnace was full of water...it looks like the condensate line had been pulled away...I reinserted it and pumped out the water. I'm wondering if this had anything to do with the causing the error code. Does anyone have advice?