[bobbyd]

I have a Goodman gmnt080-4 propane furnace. I smelled gas coming from the exhaust vent so I cleaned the blower and secondary heat exchanger coil. When I removed the burner box there is a plate between it and the heat exchanger. On of the holes in the plate had a crack where the flame had hit for to long. I want to replace this plate but I cannot find anywhere a name or part number to order one. I also noticed the four burner orifices are a smaller size than the original ones. How does that effect performance? After cleaning the blower and secondary heat exchanger coil there is still unburned gas coming from the exhaust vent. Can anyone answer these questions?
Thanks for your time

 

[roughneck]

That would likely be the heat exchanger.
The furnace is NOT safe to operate until it’s replaced.
The gas pressure should also be checked and combustion analysis performed after it’s replaced.
How old is this furnace?

 

[Guap0_]

http://goodmanrepairparts.com/equipment-type/forced-air-furnace/gmnt/gmnt080-4/


Replacement parts.