TS: i12 Getting E5 error code Vanessa October 12, 2017 16:08 Follow E5 Error Code on Your i12? The E5 error code refers to the Pressure Switch which can be caused by a motor problem or the voltage of the power supply is too low. If you're sure that the power source is within the required amount and the same issue persists, try to reset your heater by: Completely draining the unit out of water Shut off gas valve Leave unplugged for 5 minutes from power outlet Restart heater If you're still having problems with the E5? 1. The first thing to check is the backflow preventer located inside the elbow vent pipe (included on the standard horizontal vent kit) connected to the top of the heater. Make sure when you put it back that the butterfly valve inside the elbow freely moves when the fan blows the hot air out of the vent. To test, remove the top vent and run the unit without it and see if the issue goes away.2. See if the fan comes on. If not, please check the connection to the computer board. 3. Check the Air pressure or Vacuum Switch. If after checking these things and you're still having problems, please reach out to email@example.com with pictures of your installation and proof of purchase or serial number. Our team is always happy to help!