Sizing helps match the capacity of the hot water source to the needs of the homeowner. For tank water heaters, the key criterion is hot water storage capacity which is measured by First Hour Rating (FHR), as well as, number of users, bathroom and major appliance types, and usage style.

Establishing peak demand is measured in Gallons Per Hour (GPH). A tank water heater is chosen based on the GPH evaluation to meet the demand of the household.

Choosing which fuel type depends largely on where you live. If you have access to natural gas, it can be a very fuel efficient way to go. If you live in outlying areas where natural gas isn’t available, then your home would be set up with an electric or propane tank water heater.

There are a number of different types of vents which can be used with a tank water heater. Ensuring the right type of vent is installed for the type of water heater you are fitting is important. Types of vents include atmospheric vents, direct vents, power vents, and direct power vents.

Water heaters are the second highest source of energy usage in the home. ENERGY STAR® certified water heaters are an easy choice for energy savings, performance, and reliability. They use less energy than standard models, saving homeowners money on their utility bills while helping protect the climate. Performance is measured by meeting the Uniform Energy Factor (UEF) criteria. 

The Anode Rod helps prevent corrosion inside the water tank. Anode rods will last four to six years before needing replacement. A Mixing Valve’s purpose is to ensure comfortable water temperatures. If you install a mixing valve and slightly increase the target temperature on the hot water tank, you can increase the capacity of your tank up to 50%.

A great warranty lets you enjoy your HVAC equipment with confidence. RUUD®, Rheem®, and HTP® build trusted reliability into every product, providing additional peace of mind with water heater warranty protection. Hot water tank warranties range from 6 years to lifetime limited warranties dependent on size, features and brand.

First Hour Rating is the number of gallons of hot water the water heater can supply per hour, starting with a full tank full of hot water.

Gallons Per Minute is a measurement to determine the amount of water a tank water heater is capable of heating at any given time.

Uniform Energy Factor is a measure of its energy efficiency, with higher numbers denoting more efficient units.

Recovery — A water heater’s recovery time (also called recovery rate) is the amount of hot water in gallons a tank water heater can provide in one hour after being completely drained.

British Thermal Units per Hour measure the required energy to raise the temperature of 1 pound of water from 60 to 61 degrees at one atmospheric pressure.

ATMOSPHERIC VENT — Standard atmospheric venting uses a vertical or upward sloping metal duct to vent exhaust out of the home.

 DIRECT VENT — These types of water heaters bring in air for combustion from outside the home instead of using air from within the home.

POWER VENT — Power vent gas water heaters come with an electric blower fan installed on top of the unit. This requires an electrical outlet near the water heater.

DIRECT POWER VENT — Similar to direct venting, direct power venting uses a blower to pull in air from outside the home directly to the water heater to use for combustion.