June 14, 2024


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Water Heater Installation Code Requirements in 2022 (A Guide)

Water Heater Installation Code Requirements in 2022 (A Guide)

Do you want to install a new water heater and need to know the water heater installation code requirements?

If you don’t install and maintain the water heater properly, they have a high risk of exploding. There are codes for water heater installation at the local and national levels to ensure accurate installation and safety for everyone.

You and the people around you can be at high risk if you violate these codes. These codes include proper wiring, device setup, water hookup, and more. In this article, we will discuss some water heater codes for installation that you must obey if you want your unit to work efficiently.

What are Water Heater Installation Code Requirements?

Water heater installation code requirements keep your home from exploding, and it also helps in preventing water damage. A water heater is made of a large pressurized water tank. Sometimes, it explodes, so if any leakage occurs, it will cause water damage.

Water Heater Installation

International Residential Codes (IRC) is a model code in which all the water heater installation codes are laid out clearly. Many countries and states of America have adopted it. Your local state might have some differences and exceptions in IRC.

Furthermore, remember that your local state will need a permit for water heater installation, and they also require an approved plumber to do its installation.

Water Heater Installation Code

Regardless of your location, there are numerous codes that you will follow. These codes tell us about common safety matters. Due to the coding difficulty, you must appoint an expert plumber for proper installation. There are some common codes.

Bottom Board

Insulation is required to install an electric water heater in a cold place to prevent heat loss. Bottom boards are barriers with R-10 thermal resistance material or higher. It will increase the efficiency of your water heater.

Dedicated Water Shutoff

This is a valve located on the water heater to close the water supply without turning the water usage off in the rest of the house. It comes in handy for maintenance and is necessary during an emergency.

Drain Pan

Most areas want to install a drain pan with a drain pipe under it, which is always a good idea. It decreases the risk of water damage from leakages and helps when flushing.

Earthquake Straps

Areas more susceptible to earthquakes require these straps to install to prevent damage during the shaking.

Expansion Tanks

These tanks are essential if your system fails a water pressure PSI test.


If you have propane or gas water heaters, the location of your heater may be restricted to a certain area. Their purpose is to decrease the danger of CO poisoning.

Proper Venting

The gas and propane heaters release carbon monoxide gas, which must be vented outdoors. These vents should be made of appropriate materials. Make sure combustible materials are not used.

Sediment Trap

Most areas require the installation of a sediment trap as close to the gas vent as possible. They help prevent the sediment and humidity from going to the firing chamber.

Temperature and Pressure Relief Valve (T&P Relief Valve)

This is an important device for safety which turns off when the temperature goes above 210 degrees Fahrenheit or 150 PSI. Some areas require the T&P relief valve outside for more safety, and some require the installation of two T&P relief valves.

Water Pressure Devices

When the PSI goes above 80, a pressure regulating valve is required. This reduces the pressure and the risk of damage to plumbing.

California Water Heater Regulations 2022

To maximize safety, the law of California has included many additional restrictions for various materials and trades. Their water heater codes have numerous particular restrictions.

Should a Homeowner Install a Water Heater?

A homeowner can install a water heater but with specific considerations. The main point you must remember is whether DIY will violate the warranty.

Homeowner Install a Water Heater

Secondly, to install a water heater properly, many different skills are required. It can be dangerous if you don’t have the proper skills to install a water heater.


Most water heater companies approve the warranty claim only if a professional plumber does the installation. It is highly recommended to read the warranties before buying the water heater.

Skill Check

A water heater consists of different components. You will need more than one skill to install all the components properly. The requirements are slightly not severe if you have to replace the current unit with the same model, but proficiency is still required. The main skills are given below:


It is the most basic skill that a homeowner should learn before DIYing the installation. It is an essential skill for gas and water lines working, installing fixtures, and ensuring there are no leaks in the system.


Gas water heaters also have electrical components, so it is necessary to have the knowledge to deal with electrical wiring.


Since you will not be working with the wood, it is essential to know about the levels. You may need to tie up pipes to the ceiling beams. Likewise, the drywall or other exteriors may require manipulation in a finished basement.

Is it Necessary to Require a Permit for Water Heater Replacement?

Almost in all situations, if you want to replace your existing water heater, you will need one or two permits. In rare cases, they ask for a third permit.

Water Heater Permit

First of all, you need a permit for your water heater. You can easily get this by going to the building department or local planning to ask for one.

Getting a permit is more than $100. In fact, the water heater permit is the request for inspection. It contains in-depth information about the installation of the heater safely and according to the local codes.

After completing the installation process, an inspector visits your end and examines whether the installation is correct. This saves your money and also saves your life.

Common Secondary Permits

Depending on your water heater type, some states also require permits for plumbing. Many old water heaters, especially electric ones, require wire and breaker box changes.

You will need a plumbing permit to change the water and gas lines because this work is very delicate and potentially risky. A minor leak of gas can cause a big explosion. Hence, this permit will allow the inspector to check for potential issues.

Extra Permit Considerations

Older houses and new ones also need an extra permit before installing the water heater. You will need these permits if you need structural work, like making a level platform in basements or installing a cupboard for a tankless water heater.

Some areas don’t need these additional permits because they are already included in the plumbing and electrical permits.

Considerations Before Installing a Water Heater

You must keep a few things in your mind before installing the water heater and ensure you have already set up the place for the unit.

For all the water-using applications, your home’s water pressure is necessary. If it is low, your plumbing lines will increase, and the stress on the plumbing lines will be reduced.

Water Pressure of a water heater

With the help of a pressure gauge, you can check it. The perfect pressure lies between 50 – 60 PSI. If it exceeds 80 PSI, you can reduce it with pressure reducing valve. If your house doesn’t have a pressure-reducing valve, you can hire a professional to install it.

Find out the expansion tank of the accurate size according to your requirement. A thermal expansion tank keeps the pressure within a closed system. Water heaters up to 50 gallons can work with a 2-gallon expansion tank.

Thermal Expansion Tank

Use a 5-gallon expansion tank for 100 gallons of water heaters. Read the manufacturer’s guidelines to ensure you are getting the expansion tank of the right size for your system. Water heater installation must have a matching pressure with primary water pressure.

You may be required to install a drain pain under your water heater depending on your area and your unit’s location. Its reason is that if any leakage occurs, the drain pain catches the water and prevents the inside area from damaging.

Drain Pan for water heater

A water heater pan is necessary if you want to place your unit in the living room or upper floor. So, the pan will require a discharge pipe to release water to the outside area.

In apartments and living quarters, you must install a drain pan with a 3-inch drain pipe to discharge the water to the outer area.

Code for Installing a Water Heater

Fulfilling water heater installation code requirements are critical for smooth installation. You must follow the codes and standards while installing the water heater.

To install it, follow the steps given below. The codes are similar in gas water heaters, with some exceptions.

1. Set a Place for your Heater

You must place your water heater on the drain pan. Install a pipe from the drain pan to the drain to prevent flooding. In a garage, the gas water heater should be installed on an 18-inch stand. A stop post is needed in a garage to prevent a car from hitting the unit and causing a blast.

2. Temperature and Pressure Relief Valve Installation

Sometimes, the heater has no T&P relief valve. You can install this valve at this step. The valve may come with the installation kit, or you must purchase it separately.

Don’t use an old valve. If the temperature and pressure are extremely high inside the tank, this valve automatically turns on.

3. Install a Discharge Pipe

Install a discharge pipe from the T&P relief valve to the floor drain. If there is no drain underneath the pipe, you must keep a bucket, so the spillage falls into it.

The pipe size should be less than six inches above your drain pipe or bucket. If its size exceeds this, cut it and make it less than six inches.

4. Hooking Up a Water Heater

Use a flexible hose kit to hook up the water efficiently. First, apply plumbing tape to the nipple’s threads, then attach the hoses.

5. Installing the Fittings

To limit the rust between various metals, you must install dielectric fittings in different areas. The detail of these installations is given by the codes and standards of the local area.

6. Attach the Fittings

Apply the plumber’s tape to the threads of the connector. Now secure the fittings to connect the hose with the pipe. Measure the length of the pipe and cut it according to the required length.

7. Connect the Compression Nut

Put the nut onto the pipe. Tighten it after placing the pipe into the fitting.

8. Install Seismic Straps

Most of the areas require seismic strap installation to prevent damage from earthquakes. These straps secure the unit firmly to the wall and prevent the water inside the tank from spilling over.

If you live in a safe place where earthquakes don’t occur mostly, you don’t need to install seismic straps. From the bottom of the water heater, the seismic straps should be installed 18 inches away, and from the top, they should be installed at 6 inches distance.

Firmly secure the straps using bolts. Secure both ends of the strap to your stud bolt using a ratchet (a device used to make a rotating or continuous linear motion in only one direction) and socket. Use a masonry drill to create a pilot hole.

Install Seismic Straps for water heater

Adjust the size of the strap and wrap it around your unit. Using the same method, wrap another strap on the lower part. Both straps are installed in the tank’s upper third and lower third.

The lower strap should be four inches above the thermostat when installing a gas water heater. Most regions require the installation using three straps.

The straps are not required if you have to install a tankless gas or electric water heater. Lag bolts are sufficient to attach tankless units to the wall.

9. Fill the Tank

Remove the aerator from the faucet closest to the water heater, then open its hot tap slowly. Switch on the water supply slowly and check your unit’s connections for leaks.

After thoroughly checking the tank, fill it with water if you find no leaks. If you detect leakage, switch off the water supply quickly and tighten all the links. Repeat this step until the connections are secure.

10. Flush the Tank

Fill the tank with water by turning on the tap. Drain the water for 3 – 4 minutes so that all the air and debris run out from the tank.

11. Attach the Wiring

Take out the lid of the junction box. Join the ground wire to a green ground bolt. Apply the fasteners of the wire to connect the wires together.

12. Switch on the Power

Close the junction box and turn on the electricity at the circuit. If it doesn’t turn on, close the power supply at the circuit and check the connections again.

13. Set Your Water Temperature

Read the guidelines of the manufacturer to set 120 degrees Fahrenheit temperature. At the start, the water heater can take many hours to heat the water.

14. Check the Discharge Pipe

After some time, examine the discharge pipe. If the pipe is wet, this means the temperature is extremely high. Bring down the pressure to below 80 PSI.

15. Examine Aeration

After installation, if the faucet stops the water supply, remove the aerator and turn it on for a few minutes to eliminate all the residues from the tank.

FAQs – Frequently Asked Questions

Below we have discussed some crucial queries about water heater installation code requirements that one might ask.

Is it Code to Have a Pan Beneath a Water Heater?

A pan is necessary to install under the water heater if you want to place it in your living room or hall. In garages, the pans are not required to install under it in most regions.

How Close Can a Water Heater Be Placed to a Wall?

There should be a certain amount of space around the water heater so that the air can flow through that place and the heater can work effectively and safely. On all sides of the water heater, 12 inches clearance area is required.

Inside a Garage, How Much Distance Is Fine Between the Floor and the Heater?

While installing the water heater in the garage, it should be 18 inches above the floor.

What is the Appropriate Method for Venting the Water Heater?

Either vertically or horizontally, the venting of a water heater can be done. At least 12 inches of vertical venting is required for vertical venting. For direct venting, semi-horizontal piping with the lowest upward slope of a one-quarter inch per foot is required.

Should a Heater Be Raised Off the Floor?

According to National Fuel Gas Code, the water heater should be eighteen inches above the floor. This is a standard height.

Should You Use a Plastic Pan Under the Gas Water Heater?

An aluminum pan is recommended for electric and gas water heaters, and a plastic pan should be used for electric heaters only.

Final Thoughts

For safety, water heater installation code requirements should be met. The tanks of these heaters are filled with high pressure and have explosive power to destroy the whole house. Also, in case of leakage, significant flooding damage can be caused by the unit.

The essential codes require temperature, pressure relief valve, and discharge pipe. The T&P relief valve is an important safety device; the discharge pipe will prevent the nearby person from burning.