Chances are that sometime, when you least expect it, your water heater will stop heating water and you’re up the proverbial creek without a paddle. The statistics say so.
Energy.gov estimates about 27 million U.S. households have a water heater 10 to 12 years old and, since the life expectancy of storage water heaters (the most popular type in residential homes) is 10 to 15 years tops, a bunch of water heaters are going to be replaced in the next few years. Your’s may be one.
In the conclusion to our Introduction to Water Heaters, we take a closer look at two of the most popular water heater types — storage tank and tankless — and conclude with water heater issues, a few maintenance tips, and simple ways to reduce water heating bills.
Conventional storage water heaters remain the most popular water heating systems for the home.
One thing to note: Since water is constantly heated in the tank, energy can be wasted even when a hot water tap isn’t running. This is called standby heat loss. Only tankless water heaters — such as demand-type and tankless coil — avoid standby heat losses.
Some storage water heater models have a heavily insulated tank, which significantly reduces standby heat losses and lower annual operating costs.
When shopping for a storage tank water heater at one of the home improvement centers, look for models with tanks that have a thermal resistance (R-value) of R-12 to R-25. Also check with your plumber or plumbing contractor to see what brands they sell and for how much. They probably have access to models not for sale in a Lowe’s or Home Depot that may be better suited for your home.
Keep in mind: The lowest-priced storage water heater may be the most expensive to operate and maintain over its lifetime. While an oversized unit may be alluring, it carries a higher purchase price and increased energy costs due to higher standby energy losses.
Proper installation and maintenance of your water heater can optimize its energy efficiency, which is why it’s often best to use a plumber or plumbing contractor to install new equipment. Some plumbers advertise themselves as “water heater experts,” dealing almost exclusively with water heaters.
Proper installation depends on many factors, including fuel type, climate, local building code requirements, and safety issues (especially concerning the combustion of gas- and oil-fired water heaters).
Tankless water heaters are an excellent option to storage tank systems. They’re more energy efficient, although they are more expensive to purchase and they have limited flow rate depending on how the system is designed and installed.
Tankless water heaters provide hot water only as it is needed and don’t produce the standby energy losses associated with storage water heaters, which can save you money.
Tankless models heat water directly without the use of a storage tank. When a hot water tap is turned on, cold water travels through a pipe into the unit. Either a gas burner or an electric element heats the water.
As a result, tankless water heaters deliver a constant supply of hot water. You don’t need to wait for a storage tank to fill up with enough hot water.
However, a tankless water heater’s output limits the flow rate. Typically, tankless water heaters provide hot water at a rate of 2–5 gallons per minute. Gas-fired tankless water heaters produce higher flow rates than electric ones. Sometimes even the largest gas-fired model cannot supply enough hot water for simultaneous, multiple uses in large households.
For homes that use 41 gallons or less of hot water daily, demand water heaters can be 24–34 percent more energy efficient than conventional storage tank water heaters. Demand can be 8–14 percent more energy efficient for homes that use a lot of hot water (around 86 gallons a day). The average home uses 64 gallons of water a day, according to Energy.gov.
You can achieve even greater energy savings of 27–50 percent if you install a demand water heater at each hot water outlet, a strategy that’s worth discussing with your plumber or plumbing contractor when you are considering what to purchase.
Tankless water heaters also have other applications, including use in remote bathrooms or for hot tubs and they can be used as a booster for appliances like dish- or clothes washers.
Like with storage tank water heaters, proper installation and maintenance of a demand water heater can optimize its energy efficiency and save you money in the long run.
Proper installation depends on many factors, including fuel type, climate, local building code requirements, and safety issues, especially concerning the combustion of gas-fired water heaters. It’s best to have your plumber or plumbing contractor install the tankless water heater as retrofitting your plumbing or energy infrastructure may be needed to accommodate certain kinds of tankless water heaters. One manufacturer even requires changes to a home’s natural gas system.
Standard Water Heater Issues
Standard-tank water heaters are insulated and are generally reliable, but they do occasionally have problems, including:
- No hot water
- Inadequate hot water
- Rust-colored water
- Rotten egg odor
- Low rumbling or popping noise
- High-pitched whining
- Water leaking around the base of the heater
Before any troubleshooting is done, turn off an electric water heater at the circuit breaker, turn the pilot control value on a natural gas-powered water heater to “pilot”. Shut off the water supply to the water heater.
Review information on how to repair gas or electric water heaters to determine if it’s something you are comfortable doing yourself or if you’d prefer to call a plumber or plumbing contractor. Some sources include about home, The Family Handyman, the Hot Water Repair Guide, or water heaters at Home Depot or Lowe’s.
Water Heater Maintenance
Like with any system or appliance in the home, or your car for that matter, periodic service and maintenance will extend the life expectancy of the water heater, minimize efficiency loss, and save you a few bucks.
If you have a storage water heater, flush a quart of water from the tank every three months and check the temperature and pressure valve every six months. Bet most of us have not done this in the 10 to 12 years our water heaters have been working for us.
To extend the life of storage water heaters, replace anode rods (images). Frequency depends on the water heater and if your home has hard or soft water — Our area has moderate to hard water. You can do this yourself or schedule a service appointment with a plumbing company every few years to check out the integrity and performance of the water heater.
Tips for Reducing Water Heating Bills
- Use less hot water. No brainer.
- Buy a more efficient water heater and consider solar
- Purchase Energy Star appliances for everything — water heaters, dishwashers, washing machines
- Turn down the water heater’s thermostat. The recommendation is 120 degrees, but most homeowners don’t know the water heater’s temperature is set to 140 degrees.
- Wash clothes in cold water. Even warm is better than hot.
- Insulate your hot water heater tank and pipes.
- Install low-flow faucets and shower heads. These can achieve up to 25 to 60 percent water savings.