How To Look At A House

McGarry and Madsen's home inspection blog for buyers of  

site-built, mobile/manfuactured and modular homes

How do I move a water heater?

Wednesday, February 9, 2022

Relocating a water heater requires a knowledge of plumbing, along with electrical wiring or gas piping, or possibly all three, plus the building code requirements of each. If installed incorrectly, a water heater can explode like a bomb and destroy your home (really, no kidding) or flood it. So we recommend that your hire a pro to do the installation. But planning for the move is equally important, and that’s what we will cover here. Let’s start with the issues to consider for each type of water heater.

• ELECTRIC TANK WATER HEATER - Probably the easiest to relocate. Requires just an extension of piping and electrical wiring. Must be installed inside or in a protected location outside.

• ELECTRIC TANKLESS (ON-DEMAND) WATER HEATER - Needs two 240-volt breakers rated at 50 amps or more each. If converting from a tank water heater, it requires totally new, heavier wiring and breakers in panel. There are models rated to be installed outdoors, but some protection from weather is recommended.

• GAS TANK WATER HEATER - Needs new gas piping and a location that has enough air supply for gas combustion and where a flue can be extended to outside. Cannot be located in a bedroom, bathroom, or storage closet, and there are special requirements for garage installation. See our article Where are gas water heaters not allowed to be installed? for more on this. Must be installed indoors or in an enclosure outside.

• GAS TANKLESS (ON-DEMAND) WATER HEATER - If switching from gas tank water heater, you will also need 120-volt electricity. It’s simpler to install outside on a house wall, but there are models designed for an indoor location that require a flue to the exterior.

    And here’s some further specs for particular locations:

• ATTIC - A tank or tankless water heater installed in an attic must have a walkway (typically plywood) installed from the attic hatch opening to a service platform in front of the water heater. Also, a catch pan must be installed under the water heater with a drain pipe that runs to a readily visible exterior location, which typically means termination a few inches below the soffit. Go to What are the building code requirements for installing a water heater in the attic? for full details.

CRAWL SPACE - Similar to attic requirements, but with a couple of differences. See our article Can I install water heater in the crawl space by code?

• GARAGE - A tank gas water heater in a garage may require additional air supply for gas combustion from the exterior, like a vent through the wall or a ceiling vent with a flue in the attic that extends through the roof. If the gas water heater is located in the path of a car entering the garage, a stanchion or roll-stop must installed in front of the water heater to protect the gas line from unintentional impact. Also, the water heater must be raised a minimum of 18-inches above the floor or be Flammable Vapor Ignition Resistant (FVIR) rated. All gas water heaters manufactured since July 1, 2003, are FVIR.

• INDOORS - If a leak at the new tank water heater location would cause damage to the surrounding area, a catch pan must be installed under it with a drain pipe to a readily visible exterior location. Vent for combustion air from attic may be necessary for gas water heater. 

• OUTDOORS - Tank water heaters must be in an enclosure or otherwise protected from weather and freezing. Gas tankless water heaters have required minimum distances from nearby openable windows and doors, and both exterior-rated electric and gas tankless must have exposed pipes protected from freezing. Although a flush kit is not required by code for tankless water heaters, it is neccessary to avoid premature failure, and not flushing the water heater will void the manufacturer’s warranty. Go to Why should a tankless water heater have an isolator/service valve kit installed? to learn more.

    There are also several fundamental issues to consider for any water heater relocation, and here’s our list.

•• Ideally, the new location should be centrally located and not too far from the major hot-water-using plumbing fixtures in the home. If not, you might consider retrofitting a recirculation system to cut down the wait time for the hot water to arrive. See How does a retrofit hot water recirculation system work?

•• A clear area is required in front of the water heater by code to allow it to be safely serviced. More info at What is required clearance for access and working space in front of an electric water heater? and How much clearance is required around a gas water heater? for details. This is important for smaller enclosed spaces.

•• A sacrificial anode extends the life of a tank water heater, and may have to replaced to keep galvanic corrosion from causing premature tank leakage. The anode installed by the manufacturer is a solid rod about four-feet long. If the new location has limited height above the water heater, such as in a crawl space or attic, it’s a good idea to replace it with a segmented anode before installation. Go to Why do water heaters have a sacrificial anode? for more on this. 

•• Any water heater relocation will require repair of the wall at original location and safely terminating wiring and piping. Also, opening up and repairing other walls or ceilings will likely be necessary for the new location.

•• A permit and inspection for the plumbing, electrical and/or gas piping work is necessary. Your contractor may offer you the option of doing the work without a permit and it will usually not get caught because most, if not all, of the work is not viewable from the street; however, unpermitted work may be checked and become a problem when you sell the home.

    And finally, if you really want to relocate the water heater yourself, please read What are the most common installation mistakes with water heater replacement?

• • • • • • • • • • • • • • • • • • • • • • • • • • • • 

Here’s links to some of our other articles about WATER HEATERS:

How do I determine the age of my water heater?

Does a water heater need a shut-off valve?   

What is the minimum clearance to doors and windows for an outdoor tankless gas water heater?  

Are water heaters required to be raised off the floor? 

Is the minimum size water heater inlet pipe 1/2" or 3/4" according to the building code? 

Can you use a light switch for a water heater disconnect? 

How can I tell if a water heater is HUD-approved for mobile/manufactured homes?

Can you wire a 240-volt water heater with 120 volts? 

Does a tankless gas water heater still work with no electricity during a power outage?  

•  Why do water heaters have a sacrificial anode? 

Does a tankless water heater require a pressure relief valve?

When is a water heater drain pan required?

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

Is a catch pan and drain piping required for a replacement water heater?

What is the difference between a single element and dual element electric water heater? 

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

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