cordovan66
New Member
Please help me diagnose my furnace problems.
Over the last 5 years my furnace has gone dead about half a dozen times and resurrected after a few hours. It’s happened twice in the last week.
The 2 diagnostic LEDs are dead. I measured the voltage at the 24V transformer. It’s generating 27V just fine. The fuse is ok. The red wire leading to the thermostat has 0V. This kills my AC also which is what I need these days.
My guess is the Surelight board has a problem. I saw some corrosion/deposits on the big IC on it. I cleaned it with 91% alcohol but it made no difference.
The furnace is a Lennox G40UH-48B-090X-03
Can you tell me which Surelight board I need. Does anyone have a schematic of the board and any tips on what common failures on it are, if I try to fix the board instead of replacing.
Over the last 5 years my furnace has gone dead about half a dozen times and resurrected after a few hours. It’s happened twice in the last week.
The 2 diagnostic LEDs are dead. I measured the voltage at the 24V transformer. It’s generating 27V just fine. The fuse is ok. The red wire leading to the thermostat has 0V. This kills my AC also which is what I need these days.
My guess is the Surelight board has a problem. I saw some corrosion/deposits on the big IC on it. I cleaned it with 91% alcohol but it made no difference.
The furnace is a Lennox G40UH-48B-090X-03
Can you tell me which Surelight board I need. Does anyone have a schematic of the board and any tips on what common failures on it are, if I try to fix the board instead of replacing.