GSW water heater not lighting all the time
I own (4 years old) a GSW model 6G50NVH-FV-02 with a Robertshaw controller. In the past, when it failed, it would blink continuously fast. I simply unplugged it and it would restart with no problems. Now, I can see the glow plug light up and it tries to fire up (can hear gas valve open) but after three attempts, it flashess 1 - 1 which from the error code indicates ignition failure. Now if I disconnect the power again and wait 4-5 hours, it ignites on the first try. Do I need a new igniter? I would appreciate some input.