I have a brand new installation of a high-efficiency, upflow, natural gas furnace in my garage that is attached to my house.

The inspector says that I have to have it elevated 18" above the floor.

My furnace guy (consultant, I do most work myself) has told me that the inspector is wrong and because all of the ignition and burner areas are 30+inches above the floor, that I don't need to worry about it.

The inspector calls the wiring connections and switches and the electrical connections that the fan connect to "ignition sources" and says that THEY need to be 18" above the floor.

My permits use the 1997 UMC because they're old (I got them in '03).
SECTION 303.1.3
"ELEVATION OF IGNITION SOURCE: Equipment which has a flame, generates a spark or uses a glowing ignition source open to the space in whidh it is installed shall be elevated such that the source of ignition is at least 18 inches above the floor..."

The inspector quoted the 2006 UMC because that's what he had in his truck:
"ELEVATION OF IGNITION SOURCE: Equipment and appliances having an ignition source and located in hazardous locations and public garages, private garages...shall be elevated such that the source of ignition is not less than 18 inches above the floor surface on which the equipment...rests"

In the 1997 UMC there is NO definition for "ignition source" and it's worded in such a fashion that I read that "ignition source" means the place where the furnace ignites the gas in the course of operation.

In the 2006 UMC there IS a definition:
"IGNITION SOURCE: A flame, spark or hot surface capable of igniting flammable vapors or fumes. Such sources include appliance burners, burner ignitors and electrical switching devices"

Is the inspector right? If not, how do I contest this? If so, why does the HVAC guy say that he's installed 'hundreds of them' like that with no problems?

Thanks, everyone, for your opinions on this subject. I'm likely going to go to the city and argue this one.

To see my furnace pictures, look here:
--some are sideways pics online and they're big files--




Thank you very much.