Water heater drain pan and combustion air


I have a gas water heater in my home which I’m pretty sure was not installed up to code and done without a permit. I am looking at selling soon and trying to pre-resolve any issues which may come up.

The water heater is in a small alcove inside a laundry room (so in conditioned space). On the other side of the alcove is the garage, there is a vent hole cut in wall between the alcove and the garage. It’s covered with a HVAC vent grate on both sides. This was obviously added in after the fact, as they cut a hole in the drywall on both sides, took out the insulation and covered it with the vent grates.

A drain pan was installed and the same garage wall was penetrated with a 1" PVC pipe. The PVC terminates inside the garage at the garage floor.

My question is, how wrong is this? I believe this is penetrating a fire rated wall (since it’s garage on one side). Can a combustion air vent be done this way? Can the PVC drain pipe penetrate the wall that way?

Thank you!

Upon further research, it appears all penetrations between the garage and the interior laundry room are a violation due to breaking the fire wall.

I believe I could get the PVC water heater pan drain penetration compliant by wrapping it in an an appropriate intumescent collar.

The vent hole to the garage would need to be closed off. The easiest way to meet the combustion air requirements would likely be to have a metal supply pipe into the attic that extends 6" above the insulation. As long as the attic is sufficiently vented, a properly sized pipe into the attic should be able to supply combustion air. Since it’s from living space through into the attic, it wouldn’t penetrate any fire walls.

Any comments?