Natural Gas Water Heaters | CenterPoint Energy

Whether it’s a tank or tankless model, look for the ENERGY STAR label to help you select a high-efficiency model. While the initial purchase price may be a little higher than less efficient models, high-efficiency water heaters will save you energy and money over the life of the water heater. Plus, operating costs for natural gas water heaters are typically about half that of electricity or propane adding to your savings.

A natural gas water heater's burner is sized to completely recover in about one hour, regardless of the tank size.

• A 40- or 75-gallon natural gas water heater recovers in about one hour.
• An 80-gallon electric tank recovers in about four hours.

Be a smart shopper with just a little research on water heaters. After reading this page, check out a few more water-heater resources you can rely on:

• ENERGY STAR, Water Heaters
• Energy Saver, Department of Energy

A properly-sized water heater will deliver the hot water you want when you need it. Water-heater sizing considerations include:

• Number of bathrooms in home
• Number of family members & their ages
• How your family washes dishes and clothes
• Whether you prefer showers or a soak in the tub

Unlike storage tanks, tankless water heaters don’t store hot water. Instead, they heat water on demand. Their capacity is measured in gallons per minute (GPM).

Here’s a rough guide based on the number of bathrooms and showers:

• 1-2 bathrooms: tankless size of 5-10 GPM
• 2-3 bathrooms: tankless size of 8-14 GPM
• 3 or more bathrooms: tankless size of 10-18 GPM

These are general guidelines since no two families' hot water use is exactly alike. Keep in mind your family's lifestyle and habits when estimating your household hot water needs.

To extend your water heater’s operating life and keep it at peak energy efficiency, periodic care is important.

General water-heater-maintenance guidelines (follow the manufacturer's recommendations):

• Keep the burner area clean, free of dust & dirt.
• Prevent scale – a buildup of minerals – in your water heater by drawing a pail or two of water from the drain valve as often as recommended by the manufacturer.
• For tankless water heaters, manufacturers typically recommend descaling the unit at least once a year depending on water hardness.
• Have an older water heater that hasn't been regularly drained? You may want a plumber to perform the maintenance, as your water heater may already have scale deposits that make it impossible to completely close the drain valve after draining water from the tank.
• Follow the manufacturer’s instructions to relight the pilot light (when necessary).
• Wrap insulation on the hot water delivery pipe between your water heater and the point of use, as well as all pipes running through unheated areas.

• You hear a gurgling noise when the water-heater burner is on. This may be a sign of sediment/scale buildup, which can damage your water heater.
• Water is leaking from your water heater. This may indicate your water heater is failing and presents the risk of flooding and water damage.
• You frequently run out of hot water, but your household’s usage hasn’t changed. Insufficient hot water is commonly caused by mineral building in the tank. Ensure your water heater is maintained according to manufacturer’s guidelines.
• Your hot water becomes cloudy. If your cold water is clear but your hot water is cloudy it’s a sign of mineral buildup in your water heater tank.

If you’re having water heater trouble, contact a qualified water-heater technician as soon as you can.

The best way to reduce energy use for water heating is to use less hot water.

• Take short showers instead of baths.
• Install a low-flow showerhead to substantially reduce the amount of hot water used per shower.
• 120 F is a sufficient and safe water temperature for most households. Turn your water heater thermostat to the lowest setting comfortable for you and your family.
• Clothes washers (laundry) – use the shortest wash cycle and coolest water temperature possible. Make sure your rinse cycle uses cold water.
• Automatic dishwashers – scrape dishes before placing in the dishwasher. Use cold water for rinsing.
• Hand-washing dishes – turn rinse water on and off as needed. Consider a dishwasher, which uses less water and energy than washing dishes by hand.
• Promptly repair leaky faucets. A leak that fills a coffee cup in 10 minutes wastes 3,280 gallons of water a year!
• Never let water run while brushing your teeth or shaving.
• When you only need a little water from the tap, use cold water. Hot water drawn into the pipes may never reach the tap and the heat is wasted!
• Wrap insulation on the hot water delivery pipe to reduce heat loss and energy waste.

Natural gas water heaters are a safe way to heat your household water. As with all home appliances, follow the manufacturer’s guidelines and code requirements.

• Never use or store flammable products near a water heater or any other natural gas or electric appliance. Vapors from appliances can ignite flammable substances like gasoline, solvents or adhesives.
• A technician should replace chimney or vent connectors containing rust holes or corrosion.
• Inspect the "cold end' of the flue for ice build-up that could restrict exhaust.
• Ensure that the fresh-air intake is free of debris, including snow and ice.

NOTE: Manufacturers adopted a technology standard for new 30- to 50-gallon water heaters that helps prevent flammable liquids from igniting. Since older water heaters are not equipped with this resistant technology, they are more susceptible to flammable vapors. To minimize the risk of accidents, if you have a water heater manufactured before July 1, 2003, make sure the water heater is elevated at least eighteen inches above the floor.

• Keep all flammable products in tightly closed, approved containers, stored far away from all appliances and out of the reach of children.

Turn your water heater to 120 F to save energy and avoid scalding.

• Some manufacturers set thermostats at 140 F, but most households only need 120 F.
• Water heated at 140 F also poses a safety hazard of scalding. However, if your dishwasher doesn’t have a booster heater it may require 130 F to 140 F for optimum cleaning.
• Slow mineral buildup and corrosion in your appliances and pipes by reducing the water heater temp to 120 F. Help your water heater last longer!
• Save between three to five percent in energy costs for each 10-degree reduction on your water-heater thermostat’s temperature setting.