Can I install a water heater myself in Arizona?

Yes, under the owner exemption in state law. The Arizona Registrar of Contractors (ROC) licenses people who build for others. A.R.S. 32-1121 lists who doesn't need that license. Paragraph A.5 covers you as the owner. Here is its first sentence, word for word:

"Owners of property who improve such property or who build or improve structures or appurtenances on such property and who do the work themselves, with their own employees or with duly licensed contractors, if the structure, group of structures or appurtenances, including the improvements thereto, are intended for occupancy solely by the owner and are not intended for occupancy by members of the public as the owner's employees or business visitors and the structures or appurtenances are not intended for sale or for rent."

Three conditions sit inside that sentence, and all three have to hold:

• You own the property and do the work yourself, with your own employees, or with licensed contractors.
• It's for your own occupancy, not for the public or business visitors.
• It isn't intended for sale or for rent.

The statute backs up the last condition with a timing test: "proof of the sale or rent or the offering for sale or rent of any such structure by the owner-builder within one year after completion or issuance of a certificate of occupancy is prima facie evidence that such a project was undertaken for the purpose of sale or rent." It also defines "sale" or "rent" broadly, to include "any arrangement by which the owner receives compensation in money, provisions, chattels or labor from the occupancy or the transfer of the property." So a rental, a short-term rental or a flip doesn't fit.

### What about hiring a handyman to do it?

That's a different exemption, and it usually doesn't reach a water heater. Paragraph A.14 is the handyman exemption. It covers work with an aggregate contract price under $1,000. That work "shall be of a casual or minor nature." It does not apply "In any case in which the performance of the work requires a local building permit." Subsection D then takes gas work out of the handyman, retailer and product exemptions. They don't apply to "All work done, including installing, maintaining and repairing devices, appliances or equipment, that involves connecting to any supply of natural gas, propane or other petroleum or gaseous fuel."

Notice what subsection D lists: paragraphs 4, 9 and 14. It doesn't list paragraph 5, the owner exemption. So a paid handyman can't hook up a gas water heater under the handyman exemption. The statute doesn't settle every owner case for you, though: whether you may do your own gas connection still depends on your city's permit and inspection rules, so ask the permit office before you touch the gas line. Our page on licensed contractors versus handymen in Arizona covers that line in more detail, and the broader owner rules are in can I do my own plumbing in Arizona.

The license exemption only answers who may do the work. It says nothing about permits or code. Those come from your city.

Yes in Phoenix and Scottsdale. No in Mesa and Chandler for a like-for-like swap. Here is what each city's own text says, checked 2026-09-29:

### Phoenix

Phoenix is the one that trips people up. Section 105.2 of the 2024 Phoenix Building Construction Code exempts "Replacement, in kind, of an existing water heater in one-and two-family dwellings when the work is performed by a licensed contractor." Take away the licensed contractor and the exemption is gone. So a homeowner swap needs a permit. Phoenix's residential permit application has an owner box that reads: "As property owner, I am not required to use a licensed contractor because the property is intended for my sole occupancy and will not be offered for sale or rent within one year of completion (ARS 32-1121.A.5)." That's the city applying the state exemption on its own form.

Need hot water now? Section 110.3.10.1 lets replacement equipment run in an occupied home if a request for inspection is filed "not more than 72 hours after such replacement work is completed and before any portion of such equipment is concealed by any permanent portion of the building." The full Phoenix breakdown, including tankless and fuel changes, is on do I need a permit to replace a water heater in Phoenix.

### Scottsdale

Scottsdale's handout answers the DIY question directly: "A homeowner may perform the work." It follows with a caution: "A WATER HEATER MUST BE INSTALLED IN ACCORDANCE WITH THE MANUFACTURER'S INSTALLATION INSTRUCTIONS AND THE CURRENT PLUMBING CODE." The handout is undated and cites older code sections. Confirm the current details with the city before you start.

### Mesa

Mesa skips the permit for a like-for-like swap of equal or lesser rating. Replacing a "traditional (storage) gas water heater with a tankless or on-demand gas water heater" needs one. For gas units, the FAQ adds: "Notify the serving Gas Utility before placing gas appliances into service." When a Mesa permit is required, the applicant signs an affidavit. The code adds: "If the applicant claims an exemption from licensing requirements, the affidavit shall contain the basis of the exemption."

### Chandler

Chandler lists like-for-like water heater replacement as exempt. For work that does need a permit, its manual says: "Any construction requiring a permit also requires that a licensed contractor do the work unless the owner-applicant performs the work." It also says: "If you own a home that you lease or rent to others, a licensed contractor is required to obtain a permit."

No permit doesn't mean no rules. Mesa's code says exemptions "shall not be deemed to grant authorization for any work to be done in any manner in violation of the provisions of this Chapter or the technical codes." the code items below apply whether or not an inspector ever sees your garage.

One- and two-family homes in Phoenix may follow the 2024 Phoenix Residential Code, which is the International Residential Code (IRC) with local amendments. Phoenix also adopted the 2024 IPC and UPC; see what plumbing code Phoenix uses. These are the items that matter on a swap.

### Temperature and pressure relief valve and its discharge pipe

The T&P valve is the tank's last line of defense. It opens when temperature or pressure climbs too high. IRC Section P2804.6.1 (IPC Section 504.6 has a nearly identical list) says the discharge pipe must "Discharge through an air gap located in the same room as the water heater," must "Not be trapped," must "Be installed to flow by gravity," and must "Not have valves or tee fittings." It must also terminate "not more than 6 inches (152 mm) and not less than two times the discharge pipe diameter above the floor or waste receptor flood level rim." Never cap or plug it. If your valve is already dripping, why a water heater relief valve leaks explains the usual causes.

### Expansion tank when there's a check valve or PRV

Heated water expands. A check valve, backflow preventer or pressure-reducing valve (PRV) can stop it from pushing back into the city main. Then pressure builds in the tank. IRC Section P2903.4.2 says that where such a device is installed "on a water supply system using storage water heating equipment such that thermal expansion causes an increase in pressure, a device for controlling pressure shall be installed." IPC Section 607.3 says the same thing for a storage heater whose cold water "passes through a check valve, pressure reducing valve or backflow preventer." Rheem's manual explains why: in a closed system, thermal expansion "can create a rapid and dangerous pressure increase in the water heater and system piping." See do I need an expansion tank.

### Seismic strapping

IRC Section P2801.7 requires water heaters to be anchored in Seismic Design Categories D0, D1 and D2, and in townhouses in Seismic Design Category C. Whether that reaches your house depends on its seismic category and your city's amendments. Our page on water heater seismic strapping in Arizona walks through it.

### Drain pan

Where a leaking tank "will cause damage," IRC Section P2801.5 requires a pan. The pan must be at least 1 1/2 inches deep with a drain of at least 3/4 inch. There's a break for swaps: "Where a pan drain was not previously installed, a pan drain shall not be required for a replacement water heater installation." More in water heater drain pan overflow.

### Garage elevation

IRC Section P2801.6 says heaters with an ignition source in a garage "shall be elevated such that the source of ignition is not less than 18 inches (457 mm) above the garage floor," unless the unit is listed as flammable vapor ignition-resistant. See the 18-inch garage rule.

### Gas: sediment trap, shutoff, connector, combustion air and venting

• Sediment trap. IRC Section G2419.4: where one isn't built into the appliance, "a sediment trap shall be installed downstream of the appliance shutoff valve as close to the inlet of the appliance as practical." Details on our gas drip leg page.
• Shutoff valve. IRC Section G2420.5.1 puts it in the same room, "within 6 feet (1829 mm) of the appliance."
• Connector. IRC Section G2422.1 allows listed appliance connectors "located entirely in the same room as the appliance," among other methods.
• Combustion air. IRC Section G2407.1 requires air "for combustion, ventilation, and dilution of flue gases" by one of the code's prescribed methods.
• Venting. IRC Section G2425.2: "Every appliance shall discharge the products of combustion to the outdoors," except appliances the code exempts.
• Leak test. Rheem's manual says "The water heater and its gas connections must be leak tested at normal operating pressures before it is placed in operation."

### Bonding

IRC Section G2411.1 says above-ground gas piping other than CSST that is likely to become energized "shall be electrically continuous and bonded to an effective ground-fault current path." Scottsdale's water heater inspection card also lists "Proper grounding and bonding connections" among the items checked.

### Electrical disconnect for electric units

IRC Section E4101.5 says "Each appliance shall be provided with a means to disconnect all ungrounded supply conductors." For a permanently connected appliance over 300 volt-amperes, that's a branch circuit switch or breaker "located within sight of the appliance," or one that can be locked in the open position. Reusing the existing circuit on an equal swap is simple. New wiring is electrical work.

Because a mistake doesn't announce itself. The CDC puts it bluntly: "Carbon monoxide (CO) is an odorless, colorless gas that kills without warning." Rheem's manual warns: "To avoid the risk of fire, explosion, or asphyxiation from carbon monoxide, never operate this water heater unless it is properly vented and has an adequate air supply for proper operation." A vent connector that's loose, pitched wrong or undersized can spill exhaust into the house. A joint that isn't leak tested can leak gas.

Rheem's manual also says: "Installation and service must be performed by a qualified installer, service agency or the gas supplier." The law may allow you to do it. The manufacturer sets its own bar.

If you ever smell gas, stop. Our page on what to do if your house smells like gas or rotten eggs has the steps and the emergency numbers. Install a working CO alarm too; see where to put carbon monoxide alarms and can a water heater cause carbon monoxide.

### When should you hire a licensed plumber?

Follow these seven steps in order. Skipping the first two is how most DIY swaps go wrong.

1. 1Check your city first. Use the table above for Phoenix, Mesa, Chandler or Scottsdale. For anywhere else, call the building department.
2. 2Pull the permit if one is required, as the owner. Keep the inspection card near the heater if your city asks for it.
3. 3Read the new heater's installation manual end to end before you shut anything off.
4. 4Match the old unit: same fuel, same type, equal or lower rating.
5. 5Fix what the code requires on the way: relief discharge, expansion control, pan, sediment trap, shutoff and venting.
6. 6Leak test gas joints and fill the tank completely before lighting the burner or turning on the power.
7. 7Request the inspection within your city's window. In Phoenix, that's not more than 72 hours after the replacement work is completed.

If any step above feels like guesswork, it's worth a second set of eyes. HQ Plumbing and Air is licensed and insured, offers 24/7 emergency service, and gives free estimates with upfront pricing before any work starts.