Gas hot water heater in garage closet

Found a natural gas hot water heater in a garage closet that had been installed at floor level. I’ve seen gas water heaters in closet in garages before and always, without exception they are 18 inches above the floor level.

I flagged this as a safety concern and recommended that the buyer obtain further information from a qualified technician.

The closet had a self-closing metal door.

Another thing was that in addition to a six-inch fresh air intake pipe there was a vent high up on the wall that connected with the kitchen.

Another safety issue as far as I was concerned.

So I get a call from the owner’s father … he is upset because he made a few phone calls and some plumber told him the tank was perfectly okay, and the vent to the kitchen was okay.

So I told him, you get that in writing and give it to the buyer.

This is one unit in a townhouse complex that is about 12 years old. Apparently all the gas hot water tanks have been installed in this way.

The tank must be permanently isolated from the garage, or be raised to at least 18" off of the floor. The door cannot open into the garage unless the tank is elevated.

There are some heater models that can be at floor level, but they must be listed accordingly.

The vent itself is not an issue - assuming that it is not the exhaust vent.

I guess they could say that the tank was isolated from the garage, but when I inspected it, the door was wedged open. As for the vent into the kitchen, what would be the purpose of this? And if the exhaust flue was damaged, would the fumes not make their way into the kitchen?

If the door can be opened into the garage, it is not isolated from the garage. A flash-ignition could occur when/if the door is opened. That is why it must be raised within the closet.

“Isolated from the garage” means that there is no direct access from the garage. A closet door is direct access.

Water heaters and other gas-fired appliances are often located with the living spaces of a dwelling. Optimally, combustion-air is supplied through vents from the attic or exterior vent ports, but this is not necessarily required.

A recommendation for a CO detector is always prudent when gas-fired appliances are supplied or vented from the interior of a building.

As we all know “Combustion air ducts and openings shall not connect appliance enclosures with space in which the operation of a fan may adversely affect the flow of combusiton air.” (2003 IRC M1701.4) Seems like a Kitchen range vent hood might fit that bill to me. It, of course, goes on to say no combustion air from sleeping rooms, bathrooms & toilet rooms as well.

Does anybody know which year this took affect?

The year is irrelevant as you are not doing code compliance certification, but the requirement has been around for a long time. If looking for a reference, dig up an installation manual online from the mfr. It will have the requirement in it.

As mentioned, floor level installation of non-FVIR type water heater in a room opening directly into a garage is improper, regardless of when it was done.

OP: I’m curious, where did the 6 inch fresh air intake open to: garage, exterior, attic?

I just want to know when for the purpose of knowing when.

I have references that date this requirement back to the mid 60’s, but it may be even earlier than that.

2006 IRC M1307.3 Elevation of ignition source. Appliances having an
ignition source shall be elevated such that the source of ignition
is not less than 18 inches (457 mm) above the floor in garages.
For the purpose of this section, rooms or spaces that are not part
of the living space of a dwelling unit and that communicate
with a private garage through openings shall be considered to
be part of the garage