Can I Install A Water Heater Myself? Do I need A Plumber?

Can a handyman install a water heater themselves? Probably. However, water heater installation is more complicated than it sounds like. Installing a gas water heater yourself is much more dangerous than installing an electric water heater.

I will explain what all water heater installers need to know, and must be able to do, to safely complete a water heater installation.

If you are thinking about installing your own water heater as an interesting DIY project or to save some money, you might want to reevaluate the idea. Here’s why.

Can I Install A Water Heater Myself?

There are several reasons why the installation of a water heater makes up a substantial part of the total water heater installation price. With the actual cost of parts and tools, and safety, being the major factors. Much of it required by plumbing codes.

First, buying the wrong water heater for your needs will cost you plenty of money and aggravation for years. I remember many, many years ago when cars became too complicated for me to fix myself. Well, water heaters and safety regulations have gotten more complex too. So let’s take a look “under the hood” and figure this out.

Install A Water Heater Safely

Safety when installing a hot water heater is a critical factor. Making a mistake when installing a water heater may not be apparent immediately. It may take a while for problems to become visible. However, regular maintenance and correct water heater installation will go a long way in prolonging the lifespan of a water heater.

Water heater explosion video:

All water heaters do eventually fail. The main aim is to prevent a water heater failure from being catastrophic, like the video from the television show MythBusters shows.

This heater shot into the air like a rocket due to excessive pressure buildup, and destroyed the roof above it and concrete blocks below it. It clearly shows that a water heater explosion is not a myth, but real.

For the TV program, the T&P (temperature & pressure) relief valve was adjusted not to open. This can easily happen in a home due to faulty installation or irregular maintenance. This allowed pressure inside the tank to build up in excess of 85,000 pounds before it exploded.

The job of the T&P valve is to relieve excess pressure above 150 PSI, or when the water temperature gets higher than 210°F. When the valve operates correctly, it discharges boiling water through the discharge tube.

At first glance, the financial risk of installing a new hot water heater might not be so obvious.

Although the homeowners’ insurance will likely cover you for water damage, many policies only cover it if the water heater was installed by a licensed plumber.

The same applies to warranties of many water heater manufacturers, and these will be invalidated if you do the installation yourself.

To register the water heater warranty, manufacturers often require the license number of the installing plumber.

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Knowledge, Skills, Materials and Tools Required to Install A Water Heater

Water heater installers are equipped and trained to properly install many water heaters types. Including: electric, gas, tankless and tanked, as well as heat pump, geothermal and condensing. Their knowledge and skills encompass a wide range, including plumbing, carpentry, electrical and building codes.

Licensed plumbers must also be insured. This means that if a mistake is made, the homeowner is not responsible, but the company doing the installation is. If you’re not sure if the plumber has insurance, simply ask for proof.

Common Mistakes to Avoid

We often see the consequences of amateur DIY handymen installing a water heater. If you’re thinking that not much could go wrong, think again.

Is a Replacement Water Heater Really Required?

If you think you could tackle a project of this size yourself, you’re probably also pretty sure the water heater has to be replaced. It would however waste a lot of money if the wrong diagnosis was made and the water heater is replaced. Only to realize later that a bad anode rod or heating element was the problem and only those should have been replaced.

Professional plumbers run a complete set of diagnostics to find the cause of a problem before making any recommendations. A good plumber will tell you if replacing or repairing is the best option.

Purchasing the Wrong Sized Heater

A water heater’s size is the tank’s capacity, or the flowrate for a tankless water heater, and the heater’s physical dimensions. A typical home with 2.5 bathrooms and between 2 and 4 residents will need a water heater with at least a 50 gallon capacity.

Depending on how many showers are taken and how much laundry gets done, at least a 60 gallon tank may be needed. Paying extra for a bigger water heater will prevent unnecessary frustration and may even save money in the long run.

More than a single small water heater or a bigger water heater is usually required in bigger homes. Many homes may even have 3 or 4 water heaters.

Although a tank of between 30 and 40 gallons may be sufficient for a smaller home with 1 or 2 people, you need to be careful. A heater with too small a tank will run continuously to meet demand. This will wear it out sooner than it normally does.

The latest efficiency standards set by governments have led to a new breed of water heater that are better and bigger. These have however added a few inches at the bottom, top and middle.

So, in a mobile home, a new 30-40-50 gallon water heater might not fit where the old is now.

Prohibited Locations

Water heaters may not be installed anywhere. Many cities in the U.S. and globally adhere to the International Code Council (ICC) regulations, which standardize commercial and residential building codes.

In some states like Minnesota, you need a permit to install a water heater. Many cities like Minneapolis and Saint Paul have additional regulations. The local municipality must inspect the installation to ensure compliance with State and local codes.

Section M2005.2 of the International Residential Code specifies locations prohibited for electric and gas water heaters and other heating devices. It also describes additional hot water heater installation accessibility standards.

A water heater may for example not be installed in an area used for storage. When a water heater is installed in a bath- or bedroom, this must be done in sealed enclosures to prevent combustion air from being taken from living spaces.

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Difficult Locations

The IRC’s section M1305 specifies water heaters’ access requirements in locations that include under floors, and in rooms and attics.

For example, attic access must include a service space that is level for a water heater at least 30” by 30” and an opening of at least 22” by 30”. There must also be solid continuous flooring and an unhindered passageway of more than 24” wide that leads to the space, and it must be less than 20’ away from the entry.

Since April 2015, many water heaters are wider and taller than previous, similar models. New higher efficiency government standards mean that improved heat retention is required. Which results in the tank being covered by more insulation. This additional insulation can lead to a very tight fit when you need to install a water heater in some locations.

The plastic tank Rheem Marathon Model MR40245 water heater is 21.62” wide and has a capacity of 40-gallons, so it will fit in the standard 22” space if you’re extremely careful. The hot water capacity may however not be enough for a large family.

If you go for the high-efficiency model MR50238 electric water heater, it has a 50-gallon capacity and is 23.5” wide, which is wider than the standard space.

If you currently use an old tanked water heater where there is limited space, and you need to replace it with a newer model, you may have an interesting challenge to get the new unit to fit. Providing you manage to get the unit through the attic’s opening, this location has lots of space where water heaters of just about any size can be installed. One big problem is however to get the heater up into the attic.

As a water heater with a 50 gallon capacity typically weighs between 125 and 150 pounds, installation is not a job for one person. If the attic access is via a ladder, physically lifting the heater will be challenging for many people. The weight of people and the water heater together may also be heavier than what the ladder is able to cope with. Plumbers often use a rope to hoist up a tank water heater to overcome this problem.

Not obtaining A Plumbing Permit to Install a Water Heater

Local authorities can get very fussy about enforcing codes. They often send out inspectors to ensure that work is done correctly to prevent problems from happening in the future.

In the State of Oregon, like all States, replacing a water heater requires a permit.

State of Oregon plumbing permit required to install a water heater

Many DIY handymen don’t want to go through the bother and expense to get a permit. Or simply don’t obtain a permit when they improve their home as they don’t want the property tax to increase. This type of thinking can however cause big problems down the line.

In some States, when a house is sold, a seller must declare all work that was performed that requires a permit. If work was done without a permit, this will result in legal problems. The work done without a permit will also likely invalidate the homeowner’s insurance for any claim relating to the work.

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Failing to Fit a Drain Pan

Texas code requires that a drain pan be installed under the water heater’s tank.

Texas code: water heater drain pan required

As specified in the municipal code in Texas, residential tank water heaters require a waterproof, corrosion-resistant drain pan to be installed under it. The pan should be between 1.5” and 2.5” high and 2” broader than the water heater.

There should also be a fitting where a drainpipe can be attached. If the tank fails, the leaking water must be directed into a drain or outdoors.

If an existing drain pan is big enough it may be reused, but it should be inspected carefully for corrosion or damage. Depending on the location of the water heater, drain pans could be broken by things stored against them or falling on them.

If the tank in the attic starts leaking, a big volume of water could run into the pan fast, depending on the size of the leak. If the draining line is obstructed or not big enough, it will not manage to get rid of the excess water fast enough. This will lead to water damage.

Failing to Drain the Tank Completely

Once you are ready to actually perform the work, the water heater’s water supply has to be shut off. Your tank must then be drained by connecting a hose that is long enough to reach outside the building, or to reach a drain.

However, before that is done, you must open a hot water spout on the highest point in the plumbing system. This will allow air to get into the tank and it will drain completely as a vacuum is prevented from forming.

This video will show you how to drain the water heater.

Gas and Power Shutoffs

Heat must never be applied to a water heater before the heater is installed and full of water. That’s irrespective of whether it is an electricity or gas heater. Putting heat on a tank that is empty is known as dry firing, and you never want to do that.

If an electric water heaters’ heating elements are not immersed in water before it is switched on, they will quickly overheat and then burn out. Flame put into a gas water heater that is empty can cause the tank to overheat and it will crack.

Discharge Tube and T&P Valve Faults

As has been discussed, you must be sure the T&P valve works correctly. That means that hot water, when expelled, runs via the discharge tube when a water heater is installed.

It is normal for the T&P valve to discharge hot water periodically. That water should go to a drain or overflow tank. Check the requirements of the local code as some municipalities don’t specify an overflow tank has to be used, while others do.

Many DIY plumbers aren’t aware of the discharge tube installation and materials code standards. You can however not go wrong by using copper pipe.

Common errors made with discharge tubes include:

  • Manufactured from material that has not been approved – these materials include polypropylene, galvanized steel, stainless steel, or CPVC. Plastics that have not been approved may melt.
  • Discharge tube not long enough – the tube must end within 6” of a drain pan or the floor, to prevent hot water from injuring anyone close by. The bottom of the tube may not be threaded.
  • Routing discharge water improperly – the water from discharge tubes must be channeled through a line that goes outdoors, or run to a drain pan or a floor drain. It should never be connected to a drainage system directly as backflow may pollute the hot water. Discharge tubes may also never be plugged or closed off.
Gas water heater parts diagram. Plumber Near Me USA .com
  • Tube diameter not big enough. The diameter of the discharge tube may not be smaller than the T&P valve it is connected to, which is normally ¾”. There may also not be a reduction in tube size below the T&P valve’s connection.

Although sweating soldered joints when installing a water heater is the preferred method, it is necessary to know how this is done beforehand. This includes being able to use pipe cutters and removing the burrs from the ends, fluxing the joints and applying heat evenly. The torch must also be held in the correct position so the melted solder flows into joints and forms a connection that is water-tight.

Inadequate Soldering Technique

Although this skill can be acquired by just about anyone with practice, many DIY plumbers never master it. This results in a failure to understand the undesirable effects of the torch’s heat. Applying heat to copper tubing results in it traveling through the tubing. When a connection is soldered very close to the water heater’s top, the heat that travels through the tubing can cause plastic parts to melt, including the dip tube.

So, when professional plumbers install water heaters, they first detach the nipples at the top of the tank. Then they complete all except the last solder connection with the copper tubing disconnected. When doing the last soldered connection, it is done as far away from the tank as practical. The copper pipe can be kept cool by wrapping a wet rag around it.

Choice of Materials

DIY handymen who don’t want to solder often use PEX plastic tubes with push-fit or pop-on connectors as it seems simpler to install. As PEX is flexible, it’s easier to run around angles and structures. This flexibility may however cause problems.

As PEX tubing is flexible, it will bend when flow stops and starts. It will also expand and contract as the temperature changes, and this will result in the PEX line moving. This causes wear where the PEX line touches hard surfaces.

PEX should be supported and protected at corners and wherever it goes through a structure using pipe insulation, abrasion clips, or other protective materials that have been approved. Bending PEX too sharply can also result in it kinking.

Happybuy Oxygen Non-Barrier PEX Tubing 3/4 Inch 300 Feet Tube Coil

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This simple connection process is also not fool-proof. It can be tricky to align the plastic tubing with the connectors so that it maintains a watertight joint as water flow starts and stops. When good connections are achieved, they are more difficult to loosen when repairs have to be done than copper joints. PEX is also vulnerable to rodent damage and UV rays, unlike copper.

Using Different Metals

Using different metals when you install a water heater may result in a serious corrosion problem, dependent on the safeguards implemented. When different types of metal physically touch or are joined by an electric connection while submerged in an electrolyte, galvanic corrosion takes place. As water is electrolytic, a water heater tank has a sacrificial anode rod that is designed to corrode rather than other metal components, including the tank.

Galvanic corrosion will also happen if two pipes manufactured from different metals, like galvanized steel and copper are connected. If a water heater’s distribution and water supply lines are copper, and the water heater uses nipples of galvanized steel, there will be corrosion. DIY installers who don’t use dielectric connectors that are insulated are violating building codes.

Not Securing a Water Heater’s Gas / Power Supply

The tank should be strapped down or secured otherwise if it is located where it may be jolted. Although a knock might not tip a heater filled with water, it could cause leaks through loosened fittings.

Water heaters installed in areas with seismic activity need to be secured with seismic straps.


Water heater safety strap for installing a water heater in all U.S. States. See More - Click Here 

A water heater located in a garage should use bollocks, curbing, wheel stops or other structures to prevent a vehicle from bumping into it.

Electric and gas lines must also be fixed in place. Although it’s dangerous to stumble on gas or electric lines in an attic, it’s even worse if a connection gets loose and causes a gas leak. Electrical lines should be protected with conduit. Although it is not required in an attic, it’s always better to put electric lines in conduit in locations where there will be foot traffic. Wiring used in the circuits should be the correct gauge to handle the water heater’s requirements.

Automatic Shutoffs and Vacuum Breakers

Plumbing codes specify that a vacuum relief valve should be installed on tank water heaters fed from the bottom to prevent back-siphoning in cases of reduced water supply pressure.

This could happen when a fire crew flushes a hydrant or when water lines are cut. A vacuum breaker will allow air into the pipes to prevent the siphoning action from forming properly.

If a tank is emptied, dry firing can happen. This may damage a gas water heater’s tank, or burn out an electric water heater’s heating elements.

Zurn Wilkins 12-975XL2 1/2

This backflow preventer should be installed just after the water meter to protect the entire house. Available in different sizes. Check it out - Click Here 

An automatic shutoff valve must also be installed to protect against a water heater leaking while the drain pan can’t drain. If a tank leaks and drains fast, two things could happen:

  1. Water flows via the tank into the drain pan until it escapes over the edge.
  2. The empty tank overheats and can be damaged.

A shutoff device should shut off both the water and power.

MyGuard Automatic Hot Water Heater Shut Off System and Water Leak Alarm and Detector

Automatic Hot Water Heater Leak Detector and Shut Off System. Click Here 

Insufficient Venting

To keep people safe, correct venting of a gas water heater is crucial. A draft will draw combustion gasses into the flue and discharge it into the outside air when the heater is vented correctly. A flue’s pipe must have a pitch of ¼” per linear foot. This assures toxic gasses, including carbon monoxide, won’t accumulate in the house and is vented outdoors.

A flue’s back-draft can be checked by lighting a match close to the vent’s hood or through the use of a smoke wand. If smoke isn’t pulled up into the vent, there is something wrong. So, a professional plumber should be contacted to resolve the problem.

Some gas water heaters must be a specific distance away from stored items and walls. That’s to permit good combustion airflow and to keep the heater safely away from flammable materials.

Section M1306 of the International Residential Code specifies clearance distances in unfinished and finished spaces. As does the installation instructions from the water heater’s manufacturer.

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What Else To Watch Out For Before Buying and Installing Water Heaters

Consumer-grade products can be bought at big stores while professional plumbers offer professional-grade water heaters. Although there isn’t anything wrong with consumer-grade water heaters, there is a greater likelihood of problems. To make an informed decision you need to know what the differences are, including service, installation, warranties and parts.

The table shows a comparison of Rheem consumer and professional-grade products.

Consumer GradeProfessional Grade
Gas valve has a plastic bodyGas valve has a metal body
Plastic drain valveBrass drain valve
No upgrades availableAdditional anode rods can be purchased to extend the life of the water heater
Thermopile variant, which is not as reliableTraditional thermocouple is more reliable (fewer repairs)
Rheem dealers don’t carry the warranty and it must be done through contractors used by the selling company. As those contractors aren’t compensated well, you may have to wait a while and they use technicians that are less skilled.Rheem dealers carry the warranty, which covers labor, the tank and all parts. Work performed by the selling dealer’s employees.
Electric water heaters use shorter-lived copper heating elementsElectric water heaters use longer-lasting stainless-steel heating elements
Installation is extra, and often estimated on the low side; you may therefore pay more once the heater has been installed.The selling price of the heater includes installation
Replacement spares must be bought through the supplying companyGenuine replacement spares available from the Rheem dealer

The question is whether you will actually save money if you buy at big box stores and then install a water heater it yourself. This may actually often end up being more expensive than hiring a local Plumber Near Me

Summary: I Can Install A Water Heater, But I Shouldn’t

Installing a gas water heater yourself is not a simple DIY project. You should ideally have skills in carpentry, electrical, plumbing, ventilating and heating. Plus, know local and state building codes, get a permit and arrange for an inspection with your municipality.

Not complying with plumbing codes will expose you to financial, legal and physical risk. When a professional plumber is used to install a water heater, the company will assume the risk and will be insured for it.

If you do work without a permit, you put yourself at legal risk and may invalidate your homeowners’ insurance coverage relating to the work.

Although all water heaters will eventually fail, you can avoid a spectacular failure by using the services of a licensed plumber rather than doing it yourself.

Apart from not making any of the mistakes DIY plumbers commonly make when installing a water heater, you will also likely save money and end up with a higher quality water heater.

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Water Heater Plumber Near Me: 24/7 Install, Repair, Replace

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