Installing a new water heater can be a fairly complex job. Although a tankless model may be a lot smaller and more simplified when compared to the older boilers, carrying out gas or electric tankless water heater installation still requires a number of different skills. Regardless of the power source, there are always certain considerations to take into place.
Let’s take a look into the different codes, understandings, tools, and steps that are required for installing a water heater. This way, you will know what happens next after you purchase a new tankless model.
It is important to remember that although in some cases, this job can be done by yourself at home, using the services of a qualified professional comes recommended. This is due to the potential dangers and difficulties involved in this process.
Installing a New Water Heater
The big benefit of an electric tankless water heater installation is that there is no large volume of heated water that needs to be stored. Instead of relying on a boiler, these systems produce on-demand hot water.
The downside of this is that you will be restricted to the amount of hot water that the heater can produce, as the unit heats the water on-demand.
If you do undertake a gas or electric tankless water heater installation job, the unit will be more compact than a large boiler, and the job much easier to manage. This can cut down the amount of manpower and time required to install the heater.
Preparing For The Water Heater
Before you start removing and disconnecting the existing water heater, it is important to have done all the necessary preparations for the new installation. That could save you plenty of time and unwanted stress.
If you will be putting in a gas model, make sure that everything is in place first. You will need to have an up to date gas meter, with a large enough capacity to service all gas appliances in your home. You will also need to make sure that it supplies the right pressure for your heater. Gas heaters will also require the correct sized gas pipe from the meter to the water heater, venting, and the appropriate electrical power voltage.
If you are doing an electric tankless water heater installation, you will need to make sure that you have the correct wiring and electrical voltage available. You will also require a subpanel to be installed next to the unit – this is standard for building codes. The subpanel has its own circuit breakers which allow you to quickly disconnect power to the unit.
Then you will need to make sure that the space is properly sized and supported. A tankless water heater may not be a particularly large item, but it may require some carpentry to prepare the space to fit the unit.
Installing a new water heater is often done to replace an existing tank heater. If this is the case, you will need to first drain the tank before removing it. This will involve shutting off the inlet and outlet water valves, shutting off the gas line (if applicable), and removing a section of the venting pipe. Disconnecting the electrical wiring on a 240-volt unit can present a hazard, so try to get an electrician to do this part of the job.
Skills Required For Water Heater Installations
Putting in a new water heater will involve a couple of different professional skills and tools. If you are replacing an existing unit with a new one, then some of these skills may not be necessary. However, it is still good to understand everything that might be needed to get the job done.
- Plumbing – whether you are working on an electric or gas model, understand the plumbing requirements is essential. Installing a water heater of any size or style will require you to make sure that there are no leaks, that all pipes are fitted properly, and that the water pressure is correct.
- Electrical – This is more important during an electric tankless water heater installation, but gas models also have electrical parts. You will need to hook the unit up to the breaker box, and will probably have to install a subpanel as well.
- Carpentry – This is not a major area of focus, but it is still important to have a basic understanding. When installing a new unit, you will need to make sure that the space is level, well supported, and correctly sized. You may also need to work with drywall or other surfaces to get the unit properly in place.
Tankless water heaters may seem simple at a glance, and they are easier to install than old fashioned boilers. However, they still require a wide range of skills even though they are slimmer and smaller. Getting the installation wrong could result in a potentially dangerous situation.
Electric Tankless Water Heater Installation
Installing a new tankless heater will involve several steps and decisions. The first thing to take into consideration is whether the unit will be installed flush, or set into the wall. A flush unit is presented flat against the drywall or plaster. If set into the wall, the heater will need to be installed between studs. You will need to use a stud finder, and then cut holes between the studs.
Once you know how the unit will be positioned, you will need to organize the water supply. This will involve routing water supply pipes to the water heater. You will need to make sure that there is a pipe that extends from the water utility to the inlet of the heater. The outlet pipe will need to be connected to the house.
When fitting the pipes, shutoff valves will need to be installed on both ends of the heater. It is best to put these close to the unit, as they will be used in case of any emergencies.
A pressure relief valve may also be required when connecting the pipes to the heater. Union fittings will then be required for the final connections to the inlet and outlet.
When connecting the pipes, there are two main things to take into consideration. The pipes will need to be properly connected without any leaks, and the water pressure will need to be correct for the unit and house. Getting an experienced plumber to do this is generally a good idea.
Gas Water Heater Installation
Installing a gas water heater offers more complications and moving parts. While you will need to hook up the gas, you will still also have to do the electrical work as well. This means that gas water heater installation jobs are best to leave to the professionals. Working with gas also poses more dangers and risks.
The basic idea is that you will need to shut off the gas line and run a new line from the gas meter to the water heater. You will then need to add fresh air vents, connect the water inlets and outlets, and make sure that all electrics are installed properly. After that you can turn the gas back on and get your water heating.
As this can be a complex installation, its best to leave this job up to licensed plumbers.
Things to Consider With Water Heater Installation
While electric tankless water heater installation can be done by the homeowner, there are still certain codes and regulations around such a job. One important thing to note before you start installing the unit yourself is the warranty information. Many manufacturers will only approve the warranty claim if the heater was installed professionally.
Then there are permits. The laws around this differ in each state, but the general idea is that you will need either one or two permits when installing a water heater. These are easy to sort out. First, you will need to get a water heater permit when you buy a new unit. This is done to arrange for an inspection once the heater is installed. This inspection is necessary for safety reasons and it could save money as well as protect you.
Depending on your water heater, you may also require a plumbing or electrical permit. This is because some heaters require changes to your wiring and the breaker box. You would also need a permit if you will be making changes to the gas and plumbing lines. If you need to do any structural or additional work on the home during this job, you may even require further permits.
When installing a water heater yourself, you will also have to stick to the correct codes. As this is a job that involves a number of different aspects, there are quite a few codes to take into consideration.
Some of these include regulations around:
- The bottom board of the water heater
- The dedicated water shutoff
- The location of the water heater
- Proper venting
- Water pressure regulators
- Sediment traps
- And more codes depending on your area
These codes and regulations are there for your safety and benefit. Make sure that you follow them and don’t try to take shortcuts, as this could set you back significantly.
Final Thoughts
Getting a tankless water heater offers loads of benefits to the homeowner. These units are energy-efficient, fast working, and can provide a steady supply of hot water without limitations provided you have the right size. If you are planning on upgrading your water heater, then going tankless is a good idea.
Electric tankless water heater installation is something that could either be done by a handy homeowner, or through a licensed plumber. Gas is more complex. Either way, it involves a range of skills and technical understandings that a professional is best placed to perform.

