I have a -
Furnace is about 5 years old now, high efficiency natural gas. It has failed every year for the last 3 years with the same problem.
The LED blinks 4 times for ignition failure, check ground error. Watching the furnace go through its startup you can watch the solid state ignitor glow but gas fails to be delivered to the ignitor.
I'll give you the short question and the longer sorted past.
The short, Do I need a new control board?
The first time, I was able to fiddle with the furnace and it started working again for a couple days. When it failed the next time I was unable to get it to work again and called in a tech. The tech said the air sensor was faulty. Replacing the air sensor allowed the furnace to work again until the second time around a year later.
The second time, I was out of town so I had a tech come out from the same company. He said the furnace was dirty, recommended a cleaning for $200, did apparently nothing and the furnace started working for another year until the 3rd time - this time. When queried about the air sensor, he replied that it definitely was not the problem. At the time he said this was a common problem and that the control board needed to be replaced for $500, it lasted another year without needing the control board.
The third time, I fiddled with it, nothing worked, I removed the air filter and fiddled with it and it came to life. I put the airfilter back in and the furnace worked for a couple days. The furnace once again died and fiddling with it and removing the airfilter before turning it back on has allowed the furnace to live once again - who knows for how long.
My fear is that I call a tech out and they tell me air sensor or control board. If I knew for certain that this would resolve the issue, I'd shell out the repair money. I just don't want to see this thing die again next year after having replaced a part yet again or worse yet have the tech replace the part, have the furnace last whatever the warranty period is on the fix (30-90 days) and then have the furnace die again.
If you managed to muddle your way through all the background thanks just for reading!