How to convert an electric water heater to natural gas
An electric to gas water heater conversion usually means replacing the electric unit with a natural-gas water heater, not simply changing the existing heater’s wiring. The installation depends on the replacement equipment, the home’s gas access and venting, and the model’s electrical requirements. There is no single panel change that fits every home.
If you’re considering the switch, weigh potential operating-cost differences against the work involved. A gas unit is not a drop-in replacement: it must suit your household, and the installation must account for the home’s existing systems.
This guide walks through the conversion, including equipment selection, installation, electrical-panel considerations, and factors that affect ongoing energy costs. It also explains when replacing the heater makes more sense than modifying the existing setup, so you can understand the project before deciding.
Table of Contents
Installation and electrical-panel requirements
Plan around the replacement heater’s gas supply, venting route, and electrical needs. Treat panel changes as a separate assessment, not as a way to convert the electric tank itself.
Check Permits and Building CodesBefore scheduling installation, contact the building department serving your address. Ask which permits and building codes apply to the gas connection, venting, and replacement work. Requirements vary by jurisdiction and project, so do not assume a permit used for another home applies to yours. Keep the department’s guidance with your project records.
Assess Wiring, Caps, and InstallationCompare the existing electrical connection with the replacement heater’s specifications. Some gas models need electricity for controls or ignition, while others have different requirements. Do not assume old wiring can simply be capped and left in place. Identify which conductors will remain, how unused wiring will be safely terminated, and whether the panel supports the selected model.A forum discussion recommends a separate 120 V circuit and breaker for an added electric heating element when properly wired. That advice concerns an added electric element, not a standard requirement for replacing an electric tank with a gas heater. Follow the replacement model’s electrical specifications instead.
Confirm gas-line capacity. Have the proposed heater’s input requirements compared with the home’s gas service and connected appliances. No single gas-line size suits every heater. Required capacity depends on the selected unit and total demand on the line. Do not choose a pipe size by copying a neighbor’s installation or an unrelated model.
Map the connection and vent routes. Adding a gas line or vent depends on the heater’s distance from an available connection, the route through the home, and the selected unit’s venting needs. Note obstacles and possible paths during planning. For example, a route through finished spaces may require different work than one through an accessible utility area.
Record the project details. Keep the model information, electrical requirements, gas connection plan, vent route, and local permit guidance together. These details give the installation team a clear scope and help avoid missed preparation. Record decisions as they’re made, especially if the planned heater model or location changes.
Prepare the installation area. Clear access to the existing heater and planned connection points before work starts. Note nearby storage, doors, or finished surfaces that could affect equipment access or the proposed route. A clear area helps the installer assess the site and complete the planned work without avoidable obstructions. For seasonal information, check our webpage for our pre-season specials.
Operating costs and energy savings
Keep the electric heater if its operating cost is competitive and the home lacks a practical gas connection or vent route. Avoid conversion work that adds complexity without a clear household benefit. Compare energy use, local fuel rates, and installation needs first.
Compare energy bills by fuel use. Gather recent electricity and natural-gas bills, then separate water-heating use from other household loads where possible. Total bills alone can mislead because heating, cooling, and appliances affect them. Compare energy charges and usage patterns, including seasonal changes, before estimating whether another fuel could lower ongoing costs.
Account for household hot-water habits. List the routine demands that shape heating use: showers, laundry, dishwashing, and the number of people at home. A household with frequent back-to-back hot-water use may have a different cost profile from one with modest demand. Consider whether usage changes during the year, such as extra laundry during busy seasons.
Use efficiency claims carefully. Tankless water heaters can lower energy bills by up to 50 percent, depending on several factors. Treat that figure as a possible upper outcome, not a guaranteed saving for every home. Actual results depend on the unit, fuel prices, hot-water demand, and how the household uses the system.
Separate efficiency from the bill total. A more efficient heater can still cost more to operate if its fuel is expensive locally or household demand is high. Compare each option’s expected energy use with the rates on your bills. Consider equipment efficiency and fuel price together rather than judging by either one alone.
Include conversion work in the decision. Operating savings are only part of the comparison. A gas option may require a gas connection and venting, while the existing electric setup may already serve the home. Consider whether those changes make sense alongside expected ongoing energy costs, rather than focusing only on monthly bills.
Review reported performance in context. One measured converted water heater achieved 67% efficiency with hot-water consumption of 40 litres per day. That result describes a particular setup and usage level, not a universal benchmark. Use it as a reminder that measured performance depends on operating conditions, and avoid treating a single example as a forecast for your home.
Make the keep-or-convert decision. Retaining electric equipment may cost less when local electricity costs and current performance compare favorably with the full gas option. It can also avoid added gas-line and vent work. Weigh these factors against household demand and fuel rates, and judge the complete operating picture rather than assuming one fuel always costs less.
Electric-to-natural-gas water heater conversion
Plan this as a replacement project, not a change that makes an electric tank burn natural gas. The new heater, gas connection, venting, and electrical needs must work together as one system.
Select the replacement type. Choose a natural-gas model suited to the household’s hot-water demand and the home’s installation conditions. A proof-of-concept conversion was reported to work well after 10 years, but that example does not establish that a standard electric tank can be safely adapted to use gas. Base the project on purpose-built gas equipment and its installation instructions.
Check Venting and Combustion-Air RequirementsReview the manufacturer’s venting and combustion-air instructions for the exact heater model before choosing its location. Confirm that the planned vent route suits the equipment and can carry exhaust outdoors as designed. Assess how the installation space will provide the combustion air the unit requires. Do not assume an electric heater’s closet or an existing vent can serve the gas replacement.
Plan the work in sequence. Confirm the installation location and prepare the gas connection, vent route, and any required electrical supply before placing the new heater. Then disconnect and remove the electric unit, install the gas model, and test its operation. This sequence helps prevent setting the equipment in place before its supporting systems are ready.
Identify Carbon Monoxide and Gas-Leak RisksInclude carbon monoxide and gas leaks in the project’s safety review. A gas leak can release fuel, while faulty venting can allow combustion products into the home. Have connections and the exhaust path checked during commissioning. A carbon monoxide alarm can provide an additional warning, but it does not replace correct venting or safe installation.
Keep the installation information. Store the heater’s model details and operating and maintenance instructions somewhere accessible. These documents help identify the equipment when service is needed and provide the manufacturer’s guidance for routine care. Record any changes to the installation location or vent route, so future work starts with an accurate picture of the system.
Check the completed setup. Before relying on the new heater, confirm that it starts, heats water, and shuts down as intended. Review the vent termination and visible gas connections for signs of a problem, without adjusting them yourself. If you notice a gas odor or a carbon monoxide alarm sounds, leave the area and follow the appropriate emergency instructions.
Equipment eligibility
Yes, a natural-gas tankless heater can replace an electric tank if its capacity suits household demand. For Summit Utilities Oklahoma’s rebate, the unit must meet the program’s efficiency threshold and replace electric equipment.
Identify the exact replacement equipment. Record the brand, model, and equipment type before evaluating eligibility. A gas tankless heater and a gas storage heater may have different specifications, so do not assume one model’s rating applies to another. Match the information to the actual unit being considered, not a similar product or an estimate.
Compare the rating with the program threshold. Summit Utilities Oklahoma requires a natural-gas tankless water heater to be rated at least 80% UEF to qualify. Check the rating for the specific model. A unit that falls below 80% UEF does not meet this stated threshold, even if it uses natural gas and replaces an electric heater.
Confirm that the installation replaces electric equipment. The Summit Utilities Oklahoma program requires eligible equipment to replace electric equipment. Keep the existing heater’s type and the replacement model’s details together to document the change. A gas installation that does not replace electric equipment does not meet this requirement.
Check the rating through AHRI. Summit Utilities Oklahoma says AHRI determines new equipment efficiencies and recommends checking eligibility in the AHRI Directory or requesting the equipment’s AHRI certificate. Match the exact model number on the certificate or directory entry to the unit being installed. Similar model names can refer to different equipment, so use the full identifier.
Review the warranty-replacement condition. Equipment installed as a warranty replacement is not eligible for a Summit Utilities Oklahoma rebate. Establish whether the new unit is being installed as a warranty replacement before treating the rebate as part of the project decision. This condition is separate from the 80% UEF requirement and the electric-equipment replacement rule.
Decide whether tankless fits the household. A natural-gas tankless heater may suit a household when its output meets hot-water needs and the home can support its installation. Consider simultaneous use, such as a shower running while someone uses hot water at a kitchen sink. The equipment’s rating alone does not establish that its capacity suits every household.
Keep eligibility evidence together. Save the model number, AHRI rating information, and records identifying the replaced electric heater. These details help distinguish a qualifying natural-gas tankless installation from a model that misses a program condition. Review all three criteria together: equipment type, at least 80% UEF, and replacement of electric equipment.
Cost to convert electric water heater to gas in the U.S.
Request a project-specific quote. The price depends on the project and is provided after a quote request. Ask for a written scope that separates the heater, installation labor, gas connection, venting, and removal of the existing electric tank. This makes it easier to see what drives the total instead of relying on an estimate for a different home.
Describe the gas connection clearly. Note whether the home already has natural gas and where the proposed heater will sit. If a gas line must be extended, its route and access through walls, floors, or finished spaces can change the work involved. For example, a heater near an existing connection may require different line work than one across the house.
Include venting in the scope. The replacement unit’s venting design and route to an exterior termination affect installation work. Ask that the quote account for the selected model and the home’s layout, including obstacles along the path. A quote listing only the heater can omit important work and make comparisons misleading.
Compare equipment choices on equal terms. A gas tankless heater and a gas storage model can have different equipment and installation needs. Compare quotes for the same type of unit and a similar project scope. Check that each estimate identifies the model, connection work, venting plan, and removal tasks, rather than comparing a complete installation with equipment-only pricing.
Ask how access affects the work. The heater’s location can influence equipment access and how installers reach the gas line or vent route. A tight utility closet, finished ceiling, or difficult path to the installation area may affect labor. Describe these conditions before requesting a quote so the estimate reflects the actual work, not an assumed clear route.
Review what happens to the old tank. Confirm whether disconnecting and removing the existing electric heater is included in the project scope. Identify any preparation needed at the former heater location, such as handling the old electrical connection. Clear line items help explain what the quoted work covers and distinguish equipment costs from conversion work.
Compare the project total with operating plans. Consider the quoted installation alongside expected fuel use, household hot-water demand, and local energy rates. A lower upfront figure does not alone establish better long-term value. If you’re planning a tankless upgrade, request a project quote that reflects your home’s equipment and installation needs.
All Types Plumbing, Heating & Air Conditioning LLC: Hot water boiler servicing
All Types Plumbing, Heating & Air Conditioning LLC provides hot water boiler servicing for homeowners maintaining an existing boiler system. This service is separate from replacing an electric water heater with a natural-gas model, so it is relevant when a boiler needs care, not as a substitute for planning a water-heater replacement.
For households considering a tankless option, the company also provides tankless water heater upgrades. Contact All Types Plumbing, Heating & Air Conditioning LLC to discuss boiler servicing or a tankless water heater upgrade.
Plan your next step with confidence
An electric to gas water heater conversion is a home project, not just an equipment swap. Before moving forward, decide what matters most to your household: practical installation, dependable hot-water service, or the potential to change ongoing energy use. That priority gives you a useful way to weigh options without getting distracted by a single feature or sales claim.
Turn your decision into a short project brief. Note the current heater type, its location, how your household uses hot water, and questions about the proposed replacement. A clear starting point makes the next conversation more focused and keeps attention on comfort, safety, and the systems your home can support.
If you’d like help considering your home’s heating and hot-water needs, connect with All Types Plumbing, Heating & Air Conditioning LLC. Take the next step at your own pace, with a plan that fits your home.
Frequently Asked Questions
How do you do the conversion?
Replace the electric heater with a gas model suited to your household and home. Before installation, plan the equipment location, gas connection, vent route, and electrical needs. Once the new unit is installed, have the setup checked against the model’s instructions and confirm it operates as intended. For example, test hot-water delivery at commonly used fixtures and note any changes to household routines.
How much can you save?
Tankless water heaters can lower energy bills by up to 50 percent, depending on several factors, but that figure isn’t a promise of savings for every home. Your result depends on local fuel rates, hot-water use, and the equipment selected. Compare actual utility bills before and after installation, accounting for seasonal changes. This gives you a household-specific view rather than relying on a general estimate.
Can you convert an electric water heater to gas, or must you install a new unit?
For a standard household setup, replace the electric heater with a gas model rather than trying to convert the existing tank to burn gas. The two heater types use different heating systems and connections. Choose a replacement that suits the home’s available fuel and installation conditions. If you’re considering tankless equipment, compare its capacity with your household’s hot-water use throughout the day.
How long does electric-to-gas water heater conversion take, and what are the installation steps?
Installation time varies by home because the equipment and preparation differ. The sequence is to select the replacement, prepare its location and supporting connections, remove the old heater, install the gas unit, and test it. Work that requires added gas piping or a new vent route can involve more preparation than a straightforward equipment replacement.
How do gas and electric water heaters compare in operating costs, efficiency, and recovery time?
Neither fuel is automatically cheaper or more efficient for every household. Compare the specific models’ efficiency information with your electricity and natural-gas rates, then consider your hot-water habits. Recovery time depends on the selected heater’s capacity and performance, so compare product specifications rather than assuming one fuel always reheats faster. Simultaneous hot-water use can also affect which option is more practical.
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