HVAC Troubleshooting Heat Gas Valve Failure Lockout

I am a HVAC service Tech on a no heat service call. The HVAC system locks out on a gas valve failure. I find the HVAC RTU's heat draft inducer motor running, blowing cold air out exhaust. First, I reset the heating system fault. Allowing the heat to go through its sequence of operation. The inducer motor turns on, the pressure switch closes, ignitor sparks, and burners light. Since everything works, I need to dig deeper into how everything operates. Next, I test the flame signal, then the electric energizing the gas valve. After a few tests, I realize that rust prevents the flame signal to the ignition module. Therefore I clean the flame sensor and wire connectors—the flame signal increases without interference.

Видео HVAC Troubleshooting Heat Gas Valve Failure Lockout канала The HVAC Hacker