Help!!!! My mastertemp 400 pool/spa heater recently faulted with the E05 fault code. Followed the troubleshooting flow chart. Replaced the thermal regulator (due to corrosion). Dismissed gas flow as an issue since this has not been an issue in past and due to recent checks of home heating system. Also replaced stack flue sensor, as most probable cause. However the control pad is constantly on now and will not clear, any suggestions beyond replacement? I know that these control pads have subroutines which can be accessed, so can someone assist here. Thank you in advance.