Check Vital Signs of Water Heaters


Admit it--when is the last time you thought about your water heater?

Not enough people do, according to one water heater expert, and the consequence is higher utility bills and a water heater that doesn’t produce as much water as you want.

“A water heater is a significant household appliance, and people just don’t give it enough consideration,” says Frank Blow, a trade professional with Home Service Store.


Homeowners should pay attention to the capacity of their water heater, its physical condition and location.

Gas and electricity are two common energy sources for water heaters. A flame at the bottom of the tank heats gas units. A crown shield distributes heat between the flame and tank.

Electrical units contain heating elements in the tank. Electric heaters are more efficient than gas units but take longer to heat water.

Electrical units also cost more to operate. Efficiency means a greater percentage of energy is applied to making heat rather than going to waste.

Blow says the ability of a water heater to heat water quickly is important. Gas units can heat a full 75-gallon tank in one hour. Electric units take three to four hours to heat a full tank.

New model water heaters convert about 75% of their energy into heat, up 10 percentage points in the last five years.


Blow says it is not necessary for homeowners to wrap heaters with insulation, a dangerous practice if insulation restricts airflow to the heater. Manufacturers now use at least 1 inch of foam insulation inside the heater to keep water hot.

Efficiency is more than insulation. Heat traps prevent buoyant hot water from escaping out the top into pipes. And until recently, water heaters “cycled” water up to 18 times a day to keep water a constant temperature. Newer models cut cycle rates in half.

Blow says typical water heater capacity has risen from 30 gallons to 75 gallons. The reason is the surge in popularity of whirlpool tubs and larger homes with more bathrooms. One-hundred-and-twenty-gallon water heaters are not uncommon.

The average life span of a water heater depends on geographic location. In the eastern U.S., water heaters can last up to 17 years. In the West, where water is more acidic and corrodes vital parts, the appliances can last as few as five years.

Water heater safety is an issue. Normal water temperature ranges are 110 degrees to 140 degrees but can reach much higher temperatures. Most units display a warning against scalding. Homeowners can control temperatures by turning down thermostats.

Too many homeowners take water heater placement for granted. The appliances often are crammed into small spaces or crowded storage rooms with poor ventilation. Water heaters need an unobstructed supply of air. Chemicals such as bleach or solvents stored nearby that aren’t sealed will corrode the water heater and shorten the life span. Don’t store flammable liquids near the heater, either.


Routine maintenance to remove rust deposits is a good idea. Rust insulates against heat transfer on the crown shield and should be removed each year. Anode rods of magnesium or zinc inside the tank will attract rust through electrolysis and should be replaced regularly by a professional. A professional technician should only perform maintenance.

“A good professional will make suggestions to keep water heaters safe and operational while they’re doing routine maintenance,” Blow says. “We really want to make sure the heater is operational and doesn’t pose a safety threat to the home.”

One way to gauge the quality of a water heater is by length of warranty. Better heaters have longer warranties, such as six to 10 years.

“Some home centers sell water heaters with a one-year warranty, and it makes you wonder about their quality,” Blow says.