Replace a Water Heater
This is the project where the permit and the fuel type matter more than the tank. Gas, venting, and a new circuit are pro work for almost everyone.
This is a judgment page, not a step-by-step how-to. The procedure lives in the vetted links at the bottom.
The call
Hire a licensed plumber for a gas or oil water heater, any venting change, or a tankless conversion. A same-size electric tank in the same spot is sometimes a skilled DIY if your city allows a homeowner permit and you are comfortable with the wiring. When you are unsure, hire it out. A bad flue or a dry-fired element is not a small mistake.
- Difficulty
- Time
- Half a day to a full day
- DIY estimate
- $500–$1,800 for a standard tank
- Pro estimate
- $1,400–$3,500 installed for a standard tank
4 of 5
Rough national estimate, not a quote. Prices move with the city, the brand, and whatever the job turns into once you open it up.
Tools
- TODO: affiliate link
Pipe wrenches or adjustable wrenches
- TODO: affiliate link
Garden hose and a pump if there is no floor drain
- TODO: affiliate link
Tubing cutter
- TODO: affiliate link
Non-contact voltage tester for an electric unit
- TODO: affiliate link
Appliance dolly and a helper
Materials
- TODO: affiliate link
Replacement tank the same fuel and a size that fits the space
- TODO: affiliate link
New temperature-and-pressure relief valve, if the tank does not include one you trust
- TODO: affiliate link
Discharge pipe, dielectric unions, and supply fittings
- TODO: affiliate link
Shutoff valve, if the old one is unreliable
Affiliate slots are placeholders. A live shop link will be marked as sponsored. See the affiliate disclosure.
Safety notes
- Gas: if you smell gas, stop, leave, and call the gas company. Do not troubleshoot a flue or a gas valve from a website.
- Electric: shut the breaker off and test before you open the covers. Fill the tank completely before power goes back on. Dry-firing burns the elements out.
- The water you drain is scalding. Run the hose to a drain, not across a floor you care about.
- The temperature-and-pressure valve and its discharge pipe are safety devices. Don't cap them, don't reduce them, and don't aim them at a person.
- A full tank is heavy. Don't move it alone, and don't set it on a platform that was not built for the weight.
Do I need a permit?
Assume you need a permit until your city says you don't.
Water heater replacement is one of the jobs homeowners most often need a permit for. A few places treat a same-size electric swap as exempt. Gas almost always needs a permit and an inspection. Read the water heater line on your state page. If it says to check locally, or if it came from a secondary source, call the building department before you buy the tank.
On each state page, read: Water heater.
Permit triggers are local. This is general information, not legal advice. All state pages · Disclaimer
Best How-To Videos & Articles
We link to guides that already exist. We don't rewrite them.
- How To Install a Replacement Water Heater
Family Handyman · Article
- How to Replace a Tank Water Heater
This Old House · Article
TODO: add a verified YouTube link for this project.
Questions people ask first
- Should I replace a water heater myself?
- Hire a licensed plumber for gas, venting, or a fuel change. A like-for-like electric tank is sometimes DIY where the city allows a homeowner to pull the permit and you can do the wiring safely.
- How much does it cost to replace a water heater?
- A standard tank is often $500–$1,800. Installed, a typical tank job is often $1,400–$3,500. Tankless costs more. Those are rough estimates, not a quote.
- Do I need a permit to replace a water heater?
- Usually yes. Check the water heater line on your state page and call the local building department. Don't start from a general article.