Water Heater Information

Water Heater Facts

Whether you are building a new house or getting ready to replace your old water heater there are things to consider before making the decision on which hot water heater to get. You want the best system for the money but you don’t want high utility bills. We typically install Bradford White and AO Smith brand water heaters but will install any other major brand at a customer’s request or based on availability of models. give us a call and we can assist you with new construction equipment selection and design

Choosing the Right Water Heater

There are usually tax credits, utility rebates, and incentives for new construction and replacement of old equipment with high efficiency water heaters. With the rebates the return on investment might make sense while enjoying the benefits of having state of the art equipment and low energy bills.

It is usually most cost effective to replace a water heater with one that has the same size and energy source as your old one. Converting to gas or electric will usually involve gas piping and venting or the addition of an electrical circuit. You want a water heater that will provide enough hot water for your family and use the least amount of energy possible. It is best to go with a professional brand water heater rather than a big box store brand. There is a difference in reliability and quality. A water heater is an investment that should last a long time.

Size of Tank

Most residential water heaters are 40-50 gallon. It should be sized for the peak usage at the busiest time of day. The first hour rating is what gives you the water heaters capacity at peak demand. It is based on size of the tank and rate of recovery to heat incoming cold water. Most shower heads provide 2.5 gallons per minute. If you have any large capacity requirements like a soaker or jet tub this may dictate a larger capacity tank than what is listed here.

Electric tank size for number of people in family*

  • up to 3 people- 40 gallon
  • 4 people- 50 gallon  
  • 4-6 people- 55 gallon or more
  • 4-8 people- 80 gallon heat pump (if conditions permit)


Gas tank size for number of people in family*

  • Up to 4 people- 40 gallon
  • 4-people- 50 gallon  
  • 4-6 people- 50 gallon or 50 gallon high recovery
  • 4-8 people- 50 gallon high recovery or 75 gallon

*Please determine the usage for your household.

Energy Efficiency

Energy Factor (EF) is an overall efficiency rating of the water heater. The higher the EF, the more efficient the model. Water heaters with high EF ratings may cost more initially but save energy and money in the long run. Eventually, they will pay for themselves through a lifetime of energy savings.

Most gas-fired water heaters are 58-65% efficient with an EF rating of .58-.65.  Most electric water heaters have EF ratings ranging between 0.90 and 0.95. The higher the EF, the more efficient the model.

Most electric heat pump water heaters have an EF rating of 2.2 or better.

First Hour Ratings

Another important factor in choosing a water heater, the 1st Hour Rating is an indicator of how much hot water a particular model can provide. The rating, in gallons of usable (desired temperature) hot water is reached by combining the amount of usable hot water stored in the tank plus how many gallons of usable hot water the water heater can generate in one hour of operation. For example, if a 40-gallon natural gas water heater will store 31 gallons of usable hot water and can deliver 41 gallons of usable hot water in the first hour, it’s 1st Hour Rating is 72 gallons. 1st Hour Ratings are included in the Energy Factor charts.

Quick or High Recovery

A quick recovery water heater offers homeowners more hot water capacity for the same size tank. They have a higher BTU input and heat the water faster. Some models might require a 4″ vent where as the standard recovery used a 3″.  There are many custamizable options and we can provide all the information to help meet your needs and situation.