A guide to water heaters

4 min read
Water heating is a home's second-highest energy cost, so making a wise choice can lead to big savings later. Get the facts on the types of water heaters and what to look for when buying a water heater.

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Direct fired / storage water heaters

Fuel Options: oil, natural gas, electricity, propane

Direct fired / storage water heaters overview

Most common type of water heater. Storage tank water heaters have an insulated tank where water is heated and stored until it's needed. These are stand-alone systems that operate independently to other HVAC components such as a boiler.

Highlights

  • Typically, the lowest purchase price of all water heater types
  • They typically have a reservoir from 30 to 50 gallons of hot water
  • Storing water in a tank means that it will experience standby heat loss, i.e. the preheated water loses heat that you have already paid to heat up
  • Purchasing a tank with better insulation holds that heat inside where you want it
  • Look for a high Energy Factor (EF) rating for the most efficient equipment

Available Rebates: 0

Heat pump water heaters

Fuel Options: electricity

Heat pump water heaters overview

Not only do heat pump water heaters heat water, they also air condition and dehumidify the space around them.

Highlights

  • They have a higher purchase price than traditional electric resistance water heaters, but heat pump water heaters can cost half as much to operate
  • They are sometimes called “hybrid” water heaters because they can switch to standard electric resistance heat automatically when hot water is in high demand
  • They are larger than conventional water heaters
  • They have slower recovery times than other types of water heaters and it is best to size them larger than you would normally
  • Requires a condensate pump
  • Because of their noise and cooling effect, they are best suited to basements or other non-living spaces
  • Some models have smart features such as leak detection with mobile alerts

Available Rebates: 1

Indirect water heaters

Fuel Options: oil, natural gas, electricity, propane, solar energy

Indirect water heaters overview

Also known as a “sidearm tank”, these systems utilize a boiler to heat a coil inside an insulated water tank. This heats up the tank of domestic water for later use. Indirect tanks therefore require a boiler to operate.

Highlights

  • Indirect water heaters are most efficient during cold months when the heating system is used regularly
  • During warmer months, these systems can be very inefficient causing the boiler to run all year long and often heating up the area around the boiler
  • They utilize a storage tank
  • To optimize energy efficiency proper installation and maintenance of your combination water and space heating system is needed
  • We recommend having a qualified plumbing and heating contractor install it

Available Rebates: 0

Learn more about indirect water heaters

On-demand water heaters

Fuel Options: natural gas, electricity, propane

On-demand water heaters overview

These water heaters operate as a stand-alone system, much as the direct-fired/storage tank systems. However, instead of storing hot water; they heat the water as it passes through a series of coils. Since the system only heats water as you use it, an on-demand heater is usually more energy-efficient than a traditional storage tank water heater and they produce unlimited hot water at a given output.

Highlights

  • Also referred to as instantaneous water heaters
  • They don't have the standby energy losses associated with storage water heaters
  • More than one tankless unit maybe needed for large households
  • Electric on-demand units require very large power draws. Your home’s electrical service may not be adequate. Check with an electrician before installing

Available Rebates: 0

Learn more about on-demand water heaters

Solar water heaters

Fuel Options: solar energy

Solar water heaters overview

Solar water heating systems include storage tanks and solar thermal collectors. Solar water heaters come in a wide variety of designs, all including a collector and storage tank, and all using the sun's thermal energy to heat water.

Highlights

  • Solar water heating systems require a backup system for times of increased demand and less sun
  • They cost more to purchase and install than other conventional water heating systems but can save you money in the long run
  • Systems need to be properly designed and installed to optimize solar harvesting

Available Rebates: 0

Tankless coil water heaters

Fuel Options: oil, natural gas, propane

Tankless coil water heaters overview

These systems utilize a coil inside the boiler that heats up domestic water. Tankless coil water heaters are therefore fully integrated into the boiler and are often installed as a package.

Highlights

  • Tankless water heaters are most efficient during cold months when the heating system is used regularly
  • During warmer months, these systems can be very inefficient causing the boiler to run all year long and often heating up the area around the boiler
  • Tankless water heaters provide unlimited hot water at a given output
  • These systems are inexpensive but can be one of the least efficient water heating types, which increases the operating costs of the water heater

Available Rebates: 0