Seven Important Things to Consider about Electric Tankless Water Heater Installation

An electric tankless water heater installation needs expert guidance. Here are some important tips to remember before, during, and after the installation.

Darrell Smith
Tankless Water Heater Installation Tankless Water Heater Installation

Are you thinking about installing a tankless hot-water system? Do you want to benefit from more energy-efficient hot water but don’t know how to get it?

A tankless water heater—also called an instantaneous or continuous flow hot-water heater—can be a great addition to your home. Tankless hot-water systems never run out of hot water, take up less space, and are usually more energy-efficient than traditional storage systems.

In this article, we'll take you through the tankless water heater installation process as well as many other tips for maintaining your system.

1. Is an Electric Tankless System the Right Option for Me?

Before you go ahead with your tankless electric hot-water system installation, it’s a good idea to take a moment to make sure it's the right system for your needs.

One of the main things you should consider is whether your home is connected to the gas grid because gas tankless systems can often be cheaper to run than electric ones.

Having said that, electric tankless systems are much more efficient than standard electric storage systems — as much as 24%-34% more efficient.

Other options to consider are solar-powered systems as well as cutting-edge heat-pump hot-water technology. The right system for your home will depend on the design of your home, your family's hot water needs, and perhaps most importantly, your budget.

2. How Does a Tankless Hot-Water System Work?

Before you install a tankless system, it's a good idea to find out exactly how they work. With a traditional hot-water storage system, a large amount of water is heated in a tank and the system maintains its heat constantly.

In a tankless system, water is only heated if and when it's needed. Typically, water enters the system and is passed through a copper tube, which is usually arranged in the shape of a coil.

The copper coil is extremely hot and fully heats the water by the time it passes through the coil. The system is connected to an output line, which then sends water to taps and other outlets.

3. Location

One of the main reasons people go for tankless hot-water systems is that they're looking for a system that won’t take up too much space. However, you still need to think about where exactly your tank should go to best suit your needs.

Different tankless systems are designed to be connected to a different number of water outlets. Depending on the type of tank you are installing, this is going to help you make the decision for the best place to put it.

For example, some tankless systems are able to provide water to a full family, supplying three bathrooms or more at the same time.

Other tankless systems are really only designed for a single outlet such as a kitchen sink or a bathtub.

For example, German manufacturer Stiebel Eltron has a range of under-sink tankless systems that can also be integrated with purpose-built faucets.

If you're going for a larger system to supply a number of outlets, you want to install it somewhere accessible. This is because most tankless systems come with controls to allow you to change the water temperature and do system restarts when necessary.

You should also make sure the system is located so that it can easily integrate into your home’s existing water infrastructure.

If you're building a new home, a good idea would also be to locate your hot-water system so that it's close as possible to the water outlets it's supplying. If you install the system in the basement to facilitate bathrooms on the second floor, more infrastructure may be required.

4. Tankless Water Heater Installation

Unlike storage tank systems that can be more easily integrated into a gas line or electric supply, tankless installation usually requires a higher level of expertise.

One of the reasons for this is that a tankless system is designed to deal with very high short-term energy input.

If you're going to do it yourself, the first things you need to think about are:

  • The wall mount
  • The water-in supply
  • The water-out supply
  • The electrical supply

It's easiest to make these things work if your new system is being installed in the same place as the system you're taking out. This way, the in-and-out water pipes and electrical supply should be in the same place.

Mount the tank to the wall first, then connect the water pipes. Test the water flow before you connect the electrical supply by opening the water valves and checking that there are no leaks.

You should also install shut-off valves on both water lines, as well as a pressure-relief valve.

Once the water infrastructure is properly connected, integrate the system into your electricity supply and then test the unit as a whole.

DIY tankless hot-water heater installation is not something that you should do without any plumbing or electrical experience, so be careful.

5. Tankless Hot-Water Heater Maintenance

As with a normal tank storage unit, you should get regular maintenance on your tankless hot-water system. The main things you want to check are the integrity of the copper tube and the mechanical function of the heat exchanger.

The copper tube can wear out over time with repeated heating and constant exposure to water (particularly at high pressure). Likewise, the heat exchanger can undergo a lot of strain, particularly if there's a high demand for hot water in your home.

You should also replace the water filters in a tankless system to ensure the quality of the water.

It's recommended to have an expert hot-water technician look over your unit every 1-2 years to see that the system is working well. This will ensure that the unit continues to function for a longer overall period.

6. Problems With My Tankless Hot Water Heater

Although tankless hot-water systems are generally very reliable, they're not indestructible and things can go wrong with them.

Some of the signs that you should look out for are:

Loud or Strange Noises Coming From the Unit

This is a fairly obvious sign that things are going wrong. However, you need to check that the noise is coming from your tankless system and not the pipes leading in or out of it.

Noises like a ‘hammering’ sound coming from water pipes are relatively common and can be fixed quite easily by a plumber or by yourself if you know what you’re doing.

However, if the noise is coming from the unit itself, you most likely need to get expert advice. This is because there could be something wrong with the electrical coil, which can be dangerous to address yourself.

Water That's Discolored or Murky

It's unlikely that a tankless system will make your water discolored or murky since the water doesn't stay stored in the tank for long. If you're worried about the quality of your water, you can look at getting a TDS meter to test it yourself.

Water Doesn’t Heat up or Runs out Quickly

This may just be a sign that your unit is getting too old and needs to be replaced, or that there may be an individual mechanism malfunctioning.

Once again, it's a good idea to get expert tankless water heater plumbing help. You don't want to take the risks of opening up the electrical parts if you're not sure what you're doing.

Leaking System

A leaking tank is quite a common problem with traditional hot-water systems because the storage tanks eventually wear through. But if your tankless system is leaking, the problem is probably quite different.

The most likely cause is that the connections in and out of the system are loose. You can probably work out where the leak is coming from by checking to see if the tank is leaking hot or cold water.

If the leak is cold, it means it's somewhere before the water enters the coil. If the leak is hot, it's probably coming from where the water leaves the coil.

7. Tankless Water Heater Warranty

When buying a tankless hot-water heater you should make sure that it comes with a lengthy warranty. Good-quality tankless systems usually come with warranties of at least 10 years for the heat-exchanger mechanism.

Going Tankless?

Installing a tankless water heater is an excellent way to improve your home. You can benefit from never running out of hot water as well as saving money (and your environmental impact) through greater energy efficiency.

Are you looking for more ways to improve the quality of your home water systems? Start with this step-by-step guide on how to soften your water.

In this post: Tankless water heater installation, tankless water heaters, water heaters
Latest Updates

Utah's Water Quality Scores a B+

Utah earned a B+ in water quality from WaterZen. How does Utah's grade compare to neighboring states?


WaterZen Grading Methodology has assigned a letter grade for the water quality of nearly 1,500 water providers across the US. Here's our methodology.

Safe Drinking Water Act

The Safe Water Drinking Act of 1974 and Water Safety Standards in the United States

Learn all about the water regulations and reasons behind the Safe Drinking Water Act of 1974 passed by Congress to ensure that Americans have clean drinking water.

Interesting Water Facts

Seven Fascinating Facts About Water

How much do you know about water? Here are seven fascinating facts about H20.

5-Gallon Water Dispensers

Nine Factors to Consider When Buying a Five-Gallon Water Dispenser

Five-gallon home dispensers are a perfect option for home water storage. Here’s what you should know before buying any 5-gallon water dispenser or cooler.

Buying a Whole-House Humidifier

Six Key Things to Consider When Purchasing a Whole-House Humidifier

Buying a whole-house humidifier can be a daunting task if you're a first-time buyer. Here are six key things to consider when buying a humidifier.

Tankless Water Heater Installation

Seven Important Things to Consider about Electric Tankless Water Heater Installation

An electric tankless water heater installation needs expert guidance. Here are some important tips to remember before, during, and after the installation.

Fluoride in Water

Fluoride in Water: The Benefits and Risks of Fluoridation in Water

Fluoridation of public water contributes to dental and bone health for most Americans. Find out more about the pros and cons of fluoride in this article.

Collapsible Water Bottles

Five Things to Know About Collapsible Water Bottles

Are you planning to buy a collapsible water bottle? Here are five things you may not have known about these unique, flexible bottles.

Consequences of Iron in Water

What Are the Harmful Consequences of Iron in Water?

If the water in your home has a metallic taste or a brownish color, it might have a high amount of iron in it. Learn about the negative impacts of iron in water.