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Water Heaters

Use this guide to help you find which water heater you should buy.

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Choose Your Type

Standard, Tankless, or Point-of-Use

Standard Tank / Storage Tank:

The most common type of water heater. Water is heated in a tank and stored until needed.

Buy a standard tank water heater if you use a lot of hot water. If you have a family of four, you may use up to 100 gallons of water per day (think showers, dishwasher, laundry). A standard tank water heater is perfect for you.

Most tank style hot water heaters have an efficiency rating of 80%. Even more high-efficiency models are available to help you save more over time, even though they may be more expensive up front.

RHEEM-RUUD

Natural Gas Commercial Water Heater 100 gal., 120VAC, 199900 BtuH

RHEEM-RUUD

Liquid Propane Commercial Water Heater 100 gal., 120VAC, 199900 BtuH

MARATHON

50 gal. Residential Electric Water Heater 240VAC, 1 Phase

RHEEM-RUUD

6 gal. Commercial Point-of-Use Electric Water Heater 120VAC, 1 Phase

Tankless / On Demand:

Heats water as you need it, so you can enjoy a continuous supply.

Buy a tankless water heater if you are looking to increase energy efficiency and save money ... and if you’re tight on space.

They’re more energy-efficient than a storage tank, but provide only a limited flow of hot water per minute — about 3.5 gallons.

Tankless models are best for buildings that use natural gas to heat the water. Electric models need multiple dedicated circuit breakers and could require an expensive upgrade to your home or business.

Make sure you know the size of the inlet/supply and the outlet to the fixture, as well as any electrical or power supply requirements.

RHEEM

120VAC Electric Tankless Water Heater 3500W, Commercial/Residential

BOSCH

110/120VAC Electric Tankless Water Heater 3400W, Commercial/Residential

Point-of-Use:

Most commonly used under cabinets or sinks, point-of-use water heaters increase the temperature of the incoming water supply for a single fixture or appliance.

Buy a point-of-use water heater if you generally draw water for one use at a time — like taking a shower while running a dishwasher. This is a good option for sinks, home additions, detached structures, and more.

These heaters are often electric; however smaller natural gas and propane models are available in tankless and standard tank models.

Multiple point-of-use units can be connected to the same system for use in RVs, trailers, condos, light commercial, and industrial applications.

Shop All Point-of-Use

BOSCH

Point Of Use Water Heater 1440W

BOSCH

Point Of Use Water Heater 1440W

CHRONOMITE LABS

2400W Point-of-Use Electric Tankless Water Heater 120VAC

BOSCH

Point Of Use Water Heater 1440W

Pick a Fuel Source

Electricity, Natural Gas, or Propane

The simplest way to replace your current water heater is to buy one that uses the same fuel.

Switching fuel sources could cost more up front, but could save you more in the long run if you use more efficient fuels.

Gas water heaters often use less energy and cost less to run (by about half) than electric water heaters — however, gas models tend to cost more to buy.

Shop Gas Water Heaters

Shop Electric Water Heaters

 

Type

Electricity

Natural Gas

Propane

Standard
Tankless
Point-of-Use X X

 

Select a Size

Many factors are used to decide on water heater size: how many gallons of hot water you need, time it takes to heat the water, and how hot you want your water.

If you’ve run out of hot water in the past, your new water heater may require a higher GPH (gallons per hour) rating.

Standard Tank:

1. Think about the time of day you use the most water (probably the morning shower rush). Find the amount of gallons you use in that hour. This number is your gallon per hour (GPH) rating.

Your GPH should be used to work out how many gallons your water heater will need to store to meet this need.

Water Usage per Fixture

Fixture Average Gallons Per Use
Washing Machine 32
Shower 20
Bath 20
Dishwasher 14
Bathroom Sink 5
Kitchen Sink 4

2. Use the chart below to help you decide how many gallons you might need depending on the number of people in your house:

Note: The standard size tank for a home is 40-50 gallons.

Tankless and Point-of-Use:

1. Tankless and Point-of-Use water heaters are rated on gallons per minute (GPM) or recovery rating. Use the charts below to find your GPM.

Water Usage and Temperature per Fixture

Fixture Average Flow (GPM) Average Temperature
Bathtub 4 102°F
Shower 2.5-3 104°F

Washing Machine

2 120°F
Dishwasher 1.5 110°F
Kitchen Sink 1.5 110°F

 

* More than 3 bathrooms in a single home will probably require more than one tankless heater.

Larger systems that use natural gas and propane should be sized the same as a standard tankless model.

Select Your Model's BTU / Recovery Rate

Your water heater’s first hour recovery rate and BTU tells how many gallons can be heated in one hour. Add the storage capacity and you have the amount of water that can be used in the first hour.

Fast recovery units and high efficiency units offer a higher GPH than standard units. Their design heats water more quickly and efficiently than a large tank with a standard recovery rate.

Keep in Mind Ventilation & Electrical Supply

Standard Tank

Standard tank water heaters can be equipped with power vents for forced venting usage. If the existing water heater has a power vent it is best to replace it with a unit also equipped with a vent. Standard B-vent or PVC is acceptable for venting based on manufacturer’s requirements.

Electric water heaters are vent-less but have specific power supply requirements listed by the manufacturer.

Tankless

Tankless water heaters with a natural gas or propane energy source need to be vented. Manufacturers may specifically require PVC, Stainless Steel, or standard B-vent requirements for each style of heater.

Installers must ensure tankless water heaters are properly vented to avoid warranty and/or error code issues.

Electric Water Heaters

If you do not match the wattage (KW) and voltage of your old unit, you may not have enough power to use your new one.

Also, most manufacturers may not warranty a heater if you have changed wattages.

How to Find the Electricity Capacity of Your Current Water Heater

Check the label sticker on your water heater for electricity capacity info. Here you’ll find information like:

  • Volt rating (VAC)
  • Number of elements
  • Circuit breaker size
  • Total connected Watts

Match these ratings on your new water heater.

Pick Your New Water Heater

Standard Tank / Storage Tank:

Tankless / On Demand:

Point-of-Use:

 

Product Compliance and Suitability

The product statements contained in this guide are intended for general informational purposes only. Such product statements do not constitute a product recommendation or representation as to the appropriateness, accuracy, completeness, correctness or currentness of the information provided. Information provided in this guide does not replace the use by you of any manufacturer instructions, technical product manual, or other professional resource or adviser available to you. Always read, understand and follow all manufacturer instructions.