[NoHoDamon]

Manufacturer: Payne 395A AW 48090
Age: 14 years
Efficiency: unknown
Type of system: forced air
Type of fuel: NG.

Hello, I have a question about the circuit board on a Payne residential HVAC unit.

When I turned on the heat this year, there was the usual sounds of the unit firing up, but the main fan never kicked in.

Looking inside the top part of the unit, the pilot is on, and gas seems to blow across it, but the rest of the heater does not light up. There is no gas smell. The AC worked okay during the summer and the heat worked okay last winter.

Moving down to the circuit board, I noticed that the connection to the wiring harness connector was a little sooty. There are seven wires in the connector.
The ones numbered 1, 2, and 3 seem to have been arcing and the #3 (thinner/white) wire is loose. They are the ones on the right side (as you look at the component side of the board with the connector on top) The connections on the back of the card as well as the connector look bad. As far as I can tell, the other ends of the burned wires are not burned or overheated looking.

The question at this point is, should I replace the board, or is there something other than old contacts arcing and burning here that needs to be addressed?

Thanks for any information you can offer,
Damon

[NorthernHeat]

Can you see any water damage? Did the cooling coil overflow the drain pan and spill onto the PC board. If this is the 9 pin molex connector, these are all low voltage and usually won't arch.

[NoHoDamon]

As a matter of fact, it did. I noticed rusty junk coming out of the pvc pipe on the side of the house. Turned out it was a little clogged. I'm sure water could have spilled on the card when I was cleaning it out.

Does that mean the water is what caused the card and/or connections to fry, and would you suggest the replacement of the card? Do you think anything else would have been damaged by water?

Damon