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Water Heater Installation Code Requirements

These explosions are easily powerful enough to level a garage or home and cause damage around it. For this reason, there are a large number of water heater installation code requirements that need to be met when installing or replacing your water heater.
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Keeping up to code can be a real pain sometimes. Code requirements can vary widely from one state to another, and even local or county codes can play a part.

Violating these codes may result in stiff penalties or violate the warranty of your water heater. Even worse, code violations could put your family and home at serious risk.

Can a Homeowner Install a Water Heater?

water heater install

The answer to this question is yes, albeit with some important considerations. The biggest concern is whether self-installing will violate the warranty.

Second, it takes a lot of different skills to properly install a water heater (see also ‘Water Heater Keeps Turning Off (Reasons & Fixes)’). Do you have all the necessary skills for a DIY installation? Problems installing a water heater will at a minimum cause some frustration but can also become dangerous.


Many water heater companies, such as AO Smith, will only approve a warranty claim if the water heater was installed by a qualified professional. Reading these warranties before purchasing the water heater will help you avoid invalidating the terms right out of the box.

See Also:  Compare Water Heater Warranties

Skill Check

A water heater is far more than just the tank. You will need a variety of skills to properly install one. The requirements are a little less stringent when replacing an existing unit with a similar model, although some degree of proficiency is still required. The major skills you’ll need are:

  • Plumbing – The most important skill is needed for working with both gas and water lines, installing fixtures, and ensuring there are no potential leaks or pressure issues.
  • Electrical – Even gas water heaters have electrical parts and need to be hooked up to your breaker box.
  • Carpentry – Although you won’t be working with wood, you need to be familiar with levels (to ensure a level base) and may need to anchor pipes to ceiling beams. Similarly, you may need to manipulate drywall or other surfaces in a finished basement.

Do You Need a Permit to Replace a Water Heater?

water heater permit application

In almost all circumstances, replacing an existing water heater will require either one or two permits. A few rare cases may also require a third permit.

Water Heater Permit

The first permit is for the water heater itself. This is as easy as heading down to the local planning or building department to ask for one.

How much does a water heater permit cost? You’re only looking at $20 to $100 out of pocket, as opposed to several hundred dollars to call in a plumber.

A water heater permit is actually an inspection request. The permit often comes with information to help you install the heater safely and according to local codes.

After installation, an inspector will come to ensure the heater was installed correctly. This can not only save money, but potentially save your life if the installation was done incorrectly.

Common Secondary Permits

Beyond a water heater permit, some areas may also require either an electric or plumbing permit, depending on the type of water heater. Many water heaters, especially traditional electric ones, require changes to your wiring and potentially the breaker box.

Meanwhile, changes to the gas and water lines may require a plumbing permit due to the delicate and potentially dangerous work involved. A gas leak can easily cause an explosion, so this permit will ensure an inspector checks for any potential problems.

Additional Permit Considerations

Older homes (and some newer ones) may require additional permits prior to installing the water heater. These permits are for times when structural work may be required, such as creating a level platform in basements where the foundation has settled or installing a cabinet for tankless models.

In most cases, you won’t have to worry about these permits, and some regions may already include these considerations in the plumbing or electrical permits.

Water Heater Installation Code Requirements

There are several codes you’ll likely run into regardless of your location. These codes address common safety concerns. California residents will also face additional codes that are statewide. Because of code complexity, it makes a lot of sense to pay a professional plumber for proper installation.

Some Common Codes

  • Bottom Board – Electric water heaters require insulation when placed in an unheated area to prevent heat loss. Bottom boards are a buffer made of R-10 or better thermal resistant material that increase the efficiency of your electric heater.
  • Dedicated Water Shutoff – This valve allows you to shut off the water supply to your tank without sacrificing usage in the rest of the house. It’s useful for maintenance and essential during a crisis.
  • Drain Pan – While always a good idea, most areas require a drain pan with a drain line under it. This reduces the risk of water damage from leaks and aids during flushing.
  • Earthquake Straps – Areas prone to earthquakes (and some that are not) will require the water heater to be strapped in place to prevent damage during a quake.
  • water heater </strong>expansion tank codeExpansion Tanks – Some systems are considered “closed”, meaning the backflow is blocked. As water heats, it creates pressure that can stress the heater and other areas of your plumbing. Expansion tanks are required if your system fails a water pressure PSI test.
  • Location – In the case of gas or propane heaters, the location for your heater may be restricted. These restrictions are meant to reduce the risk of CO poisoning.
  • Proper Venting – Gas and propane heaters emit carbon monoxide, which must be vented outside. These vents must be made of suitable materials and be kept clear of combustible materials.
  • Sediment Trap – Many locations require a sediment trap to be installed as close to the gas inlet as possible. These traps prevent sediment and moisture from entering the firing chamber.
  • T&P Valve – The temperature and pressure relief valve is an important safety device which goes off when your tank exceeds 210 degrees Fahrenheit or 150 PSI. Many regions require the T&P valve to lead outside for added safety, and some may even require two valves for redundancy.
  • Water Pressure Regulators – A pressure regulating valve is required when the PSI exceeds 80. These reduce pressure and the risk of a cracked lining or damage to plumbing.

California Code Requirements

California law includes many additional restrictions for a wide range of materials and trades meant to maximize safety. The California water heater code is part of a larger statewide California Plumbing Code and has several very specific restrictions.

You can peruse the complete water heater code here.

author avatar
Anthony Barnes
Anthony Barnes is the founder of Water Heater Hub and a second-generation plumber by profession. Before developing Water Heater Hub, Anthony Barnes was a full-time plumber, and he has undertaken a wide variety of projects over the decades. As a second-generation plumber, it was easy for Anthony to get used to the technicalities of all from a tender age


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