Gas Furnace not Venting Properly

[Mr. Whatever]

home inspector said gas furnace is not venting properly. it's an older furnace that doest have the prepurge fan. aside from the vent being screwed up, what else could cause this problem? TIA

[Speedy Jim]

Birdnest or raccoon in chimney. Chimney collapsing. Snow blockage.

Jim

[Joseph Meehan]

Do you have a something else in the same vent, like water heater?

[m Ransley]

Ask the inspector he has to be specific and detailed, or do you want us to guess? It could be 7 things that come to mind, ask him..not us.

[Mr. Whatever]

nothing else tied into vent. no obvious problem with vent piping. i'll check from roof after the rain stops.