petchopper03 Report post Posted October 11, 2016 When I close the door to the unit the air fuel mixture changes. Adjusting mixture doesn't help. Share this post Link to post Share on other sites
dickandlois Report post Posted October 12, 2016 petchopper03, Welcome to the FMCA Forum ! Clean the circuit board connections with a pencil eraser, check for good grounds and for 12 volts at the water heater. Check the heater flame tube is clear of any obstructions, and make small incremental step ajustments. It does not take much of a change to get the fuel to air mixture out of whack. Does the heater keep running OK for an extended time with the door open? Rich. Share this post Link to post Share on other sites