[Keith Stickler]

I have a Goodman GMNT080-4 gas furnace. It stopped working and in checking it out, the control board was corroded, due to moisture ,and some of the dioids ends were rusted and broken from the sodder . I replaced the control board (B18099-13), but it still would not work. I have power to the board, the board is getting 24V and I checked and re- checked the grounds and they are good. I got the gas to come on but only for one minute and it went off. The AC came on one time and stayed on until it turned off but would not come on again on its own. When I pull the wire from the L200-30F sensor, the fan and exhaust will come on and the board gives me the 4 lights showing an open circuit. Whem plugged back up, the board light is steady showing no problems, the exhaust fan goes off and the unite dose its 150 sec. time out . Can you give me any advice.
Thanks
Keith

[mygirlsdad77]

It sounds like you may have multiple issues with the unit. With the info given, it would be near impossible to trouble shoot this through a keyboard. I hate to say it, but your best bet is going to be having an onsite hvac tech come out to check the system. The one minute fire time makes me think you need to clean the flame sensor. However, that does not explain why the ac is not working correctly. This could be a thermostat problem, but it is almost impossible to say for sure without being there first hand and being able to put my hands and testing equipment to the unit. Sorry I couldn't be of more help.

Lee.