What to Consider When Buying an Energy-Efficient Water Heater

choosing an energy efficient water heater


The home water heater can be a significant draw on your household energy use. Many homeowners are beginning to look into water heaters that are more energy efficient.

There are more varieties to choose from than ever before. Here are some of the things to keep in mind in when you’re looking to buy a new, efficient water heater.

There are several main types of energy-efficient water heating systems: tankless, in-direct, solar and heat pump. Well, there are actually two types of tankless water heaters — on-demand or coil. With all these different systems to choose from it can be difficult to know what to buy. Let’s go over the pros and cons of each type of water heating system:

On-Demand Tankless Water Heater

The on-demand tankless water heater, as the name implies, works without a tank. Basically, it is a unit containing heating coils. When a hot water tap is turned on in the home, it flows into this unit, which is about the size of an average household fuse box. There are pros and cons with this kind of water heater:

Pros of on-demand tankless water heaters

On-demand tankless heaters use less space than conventional water heaters. They also use less energy, since there is not a reservoir of water to keep hot around the clock. They have a lifespan of about 20 years, and you don’t have to worry about running out of hot water.

Cons of on-demand tankless water heaters

Tankless, on-demand heaters can be expensive. The installation will need to be done by professionals, adding a bit to the cost. Also, gas-powered ones can actually waste energy due to the constant pilot light.

Tankless Coil Water Heater

The other kind of tankless water heater is called a tankless coil. A heating coil or heat exchanger is installed in the home’s existing furnace or boiler. The water passes over coils, heated by the home heating system, and comes out of the tap hot.

Pros of tankless coils

The tankless coil uses the energy already being generated by the household heating unit, making it energy efficient. It takes up little if any additional space.

Cons of tankless coils

In warmer climates, these kinds of water heaters make little sense. They work best in climates where the furnace or boiler is already being used often. And once again, a professional installer is necessary.

Indirect Water Heaters

This kind of water heater works on the principle of the tankless coil, but it does involve a tank. Coils, heated by the home’s heating system, are inside the tank. The water gets heated as the household heating unit runs. Therefore, no extra energy is used to heat the water.

Pros of indirect water heaters

Indirect water heaters make use of the heat already being generated by your home heating system. The hot water then augments the central heating unit, reducing energy use even more. If the tank is insulated, this is a very energy-efficient system.

Cons of indirect water heaters

The tank takes up space, and the house’s furnace or heater has to be running for it to work.

Solar Water Heaters

These water heaters use sunlight to heat water. They involve a solar collector and a storage tank for the hot water.

Pros of solar water heaters

Sunshine is free and renewable. An insulated holding tank is very efficient, even free, to operate.

Cons of solar water heaters

Solar water heating systems can be complex and expensive to set up, even if inexpensive to operate. And you will need a back-up system for cloudy days and for when it’s dark.

Heat Pump Water Heater

Like a heat pump for your home, heat pump water heaters simply transfer heat from one place to another.

Pros of heat pump water heaters

These are very inexpensive to operate. They can be added on to an existing heat pump, especially a geo-thermal one.

Cons of heat pump water heaters

They are expensive to purchase. They involve a tank, which takes up space.


  1. I have become more concerned with how our actions have been affecting the environment lately. I appreciate the advice that choosing a solar powered water heater does have its disadvantages, especially in the winter when the days are dark. Getting a backup is something I didn’t think we would have to do, but it makes sense!

Speak Your Mind

Connect with Facebook