How To Look At A House

McGarry and Madsen's home inspection blog for buyers of  

site-built, mobile/manfuactured and modular homes

Can I leave a gas water heater in place when remodeling a garage into a family room or bedroom?

Sunday, July 8, 2018

There are two issues to deal with if you want to leave the water heater where it is when remodeling a garage into living space for your home:

  1. Supplying air for combustion - Once the room becomes an indoor space, the calculation to allow it to use indoor air is complicated. The air infiltration (leakage of air into the home from the outside) must equal 0.40 ACH (Air Changes per Hour), plus there must 50 cubic feet of air volume in the room for each 1,000 BTU rating of the water heater. A typical 40-gallon water heater rated at 38,000 BTU would need 1900 cubic feet of air, equivalent to a 15 foot by 16 foot room with an 8 foot ceiling.
        The better solution is to put it in a closet that separates it from the living area and has an outdoor air source, typically a high and low duct coming down from the attic.
  2. Carbon monoxide poisoning - Any obstruction in the water heat flue can allow combustion gas byproducts, including carbon monoxide, to backup into the room. This is especially dangerous if the water heater is in a bedroom (called a “sleeping room” in the building code). So a gas water heater cannot be installed in a bedroom, bathroom, or a closet opening onto a bedroom or bathroom (with the exception of a direct-vent water heater), unless it is inside a dedicated enclosure, with a solid, weatherstripped, and self-closing door, with a sweep at the bottom and all combustion air supplied from the exterior.

    Two ways to get around all these requirements are to replace your gas water heater with an electric one at the same location, or install a tankless gas water heater at an outside wall near the original water heater location. The electric water heater will likely be the more cost-effective solution of the two.

    Visit our WATER HEATERS and REMODELING pages for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.

Water Heaters

Water Heater Age

Wells

Septic Tank Systems

Structure and Rooms

Plumbing Pipes

Termites, Wood Rot

& Pests

Sinkholes

Stairs

When It First

Became Code

"Should I Buy A..."

Park Model Homes

Site

Shingle Roofs

Safety

Stucco

Remodeling

Wind Mitigation

Roof and Attic

"Does A Home

Inspector...?"

Pool and Spa

"What Is The Difference Between..."

Radon

Brick

Plumbing

Concrete and

Concrete Block

Metal Roofs

Foundations

Modular Homes

Rain Gutters

Mold, Lead & Other Contaminants

Condominiums

Older and

Historic Houses

Crawl Spaces

Mobile-Manufactured Homes

Building Permits

Life Expectancy

Clay Soil

Insurance

Floors

Insulation

Toilets

Exterior Walls

& Structures

Generators

Common Problems

HUD-Code for

Mobile Homes

Garages and Carports

Flat (Low Slope) Roofs

Electrical Panels

Sprinkler Systems

Electrical Receptacle Outlets

4-Point Inspections

Hurricane Resistance

Frequently Asked Questions (FAQ)

Home Inspection

Heating and Air Conditioning

Building Codes

Fireplaces and Chimneys

Inspector Licensing

& Standards

Energy Efficiency

Washers and Dryers

Electrical

Kitchens

Doors and Windows

(placeholder)

Cracks

Electrical Wiring

Click Below  

for Links

to Collections

of Blog Posts

by Subject

Plumbing Drains

and Traps

Appliances

Smoke & CO Alarms

Aging in Place

Top 5 results given instantly.

Click on magnifying glass

for all search results.

Bathrooms

Lighting

AFCI, CAFCI,

DFCI, & GFCI

Sinks

Air Conditioner & Furnace Age/Size

Attics

Electrical Switches

Siding

Search

This

Site

Water Intrusion

Electrical - Old

and Obsolete

(placeholder)

Foundation Certifications

Tiny Houses

About Us

(placeholder)