BFL13 wrote:
I have the 8531-II and have some parts from a III in it. I can't keep the part numbers straight. I found this info:
"Note there are three versions of gas valves that are applicable to the models listed below. Prior to ordering, please compare the picture of the valve to your existing valve to ensure that you are ordering the correct gas valve. If you have a 31096 or 31097 gas valve, you must order the 31155 and transfer the fitting, coil harness and the gas manifold from the old unit."
from:
https://pantherrvproducts.com/31098/
I have a photo of either the II or III's with some other parts-burnt out burners etc. That shows how the gas valve is in a II or III (same). Not sure what is meant by "side" in the OP
What I mean by “side” is…if I assume the gas outlet feeding the burner is the “front” of the valve, then the gas inlet is on the rear of the valve feeding straight through. However, mine also has a 90 degree fitting and then a short “S” fitting at the inlet so that the gas line actually enters the furnace box from the side. The replacement gas valve shown in your Panther link is the one I was looking at with the inlet on the side where my gas line enters the furnace box without the two fittings I mentioned. It looks like it should work but I figured I’d ask before I blew anything up.