Cold Facts About Water Heaters

The good old days in Orange County? Sure, there were no SigAlerts at the turn of the century. Pollution was at a minimum, and doctors made house calls. But to jump-start the morning, most of our great-grandparents had to fire up the stove for big, heavy kettles of water for bathing.

It wasn’t until the 1920s that the water heater became a fixture in most homes, reliably providing hot water with the turn of a spigot. Water heaters haven’t changed much since, and they are so reliable that it’s often easy to forget you have one--until you wake up to a cold shower or find the garage flooded.

In the United States, the average water heater lasts 13 years, enough to spout off 20,000 baths, showers, dishwashing and laundry loads for the typical family, according to the American Plumbing Assn.

But can you extend the life of your water heater? And what do you need to know before buying a new one?

First, a primer on what’s inside that big white cylinder.

The Works

If you were able to remove the top of your water heater, you’d see that the water is contained in a doughnut-shaped tank. Going up the middle of the tank is a vent; going to the bottom of the tank is a cold water inlet.

At the top is the hot water outlet and an overflow valve with a pipe that extends out of the water heater. At the bottom is the heating element, gas or electric, which is operated by a thermostat.

When hot water is used in the house, water from the cold inlet is delivered to the bottom of the tank. The hot water, which naturally rises, is forced through the upper outlet. The thermostat detects a fall in water temperature and turns on the heat.

Ever get the shower last in the morning and find that the hottest water you get is lukewarm?

Under heavy use, with lots of water flowing through it, it’s impossible for the heater to keep the water at a high temperature. After emptying, it takes about an hour for the gas-powered tank to heat up to normal, two hours for an electric model.

One big question regarding a water heater is how hot it should be.

Set the thermostat too high, and you’ve created a hazard in your home, especially if you have small children who can reach the tap and risk being scalded. Set it too low, and your dishwasher won’t get plates as clean as they should be.

“About 110 to 120 degrees is adequate for most people,” says Scott Blanke of Central Plumbing & Heating Supply in La Habra. “That’s at about the middle of the dial on the thermostat. And don’t forget, before going on a trip, to turn the thermostat down to the lowest level, or where it says ‘pilot.’ You don’t want to be heating water no one will use.”

If you want to conserve even more energy and lower your electric bill, install a thermostat that turns the water heater off at night when you aren’t using it and puts it back on in time for early risers.

Lukewarm No More

Suddenly, all you get from the shower head is a cold spray. If yours is a gas water heater, the problem could be a bad thermocouple. Electric water heaters have a heating element at the bottom of the tank that wears down over time.

But these problems are minor compared with the disastrous sudden leak. Over the years, you’ve forgotten about the water heater enough to let it gather dust in its closet or in the garage. Then you wake up one morning to find a new lake.

The culprits: scale and corrosion.

If you could develop a water heater that doesn’t corrode, you’d have a water heater that would probably outlive you. “But scale, the mineral deposits found in water, helps create the corrosion that eventually causes the water heater to fail,” says Joel Gwartz of B.J. Discount Plumbing & Heating Supply in Garden Grove.

With every morning shower, scale builds up on the inner walls.

“As the deposits build up, they insulate the water from the heat at the bottom, meaning the water takes longer to warm. It can also cover and foul the thermostat, making the water temperature incorrect. Scale really damages the water heater; I’ve seen pieces as big as a fist taken from old ones,” Gwartz says.

Scale breaks down the baked enamel finish inside the water heater and lets rust do its thing. Corrosion usually starts around the pipe joints or welds or at the bottom of the tank and eats away until water begins to escape.

An anode rod is used to fight scale and corrosion. The rod, made of magnesium or aluminum, sits in the middle of the tank and is designed to slow or stop the chemical process of corrosion. However, after a few years, the anode tends to disintegrate. Once it’s gone, the rusting process rolls on until water starts dripping under the heater.

If you find a puddle, don’t assume the worst. Check the fittings around the pipes leading in and out of tank, as well as the pressure relief and temperature valves. Condensation around the tank can also cause dripping water.

“But if there’s a hole in the tank, there’s no fixing the problem--the tank needs to be replaced,” says plumber K.J. Pullman of Westminster.

What’s That Noise?

Unfortunately, you can’t open up your water heater to clean out the scale. Draining it may remove some of the particles near the bottom of the tank, but not the scale attached to the insides.

You can, however, replace the anode rod. It requires turning off the water going into the water heater and getting access to the top, but it can give your water heater more life.

“Ideally, you’d want to do this every three to four years, depending on the mineral content of water in your area,” Gwartz says.

One common complaint about an old water heater is that it makes a bubbling, gurgling noise.

“As the heater burns, sediment on the bottom bubbles up and creates this popping noise,” Blanke says. “There are plumbing services available that will remove the loose sediment for you. They have powerful vacuums that pull it out of the unit. This won’t remove scale, but it will make the water heater more efficient.”

Hot Buys

Because you probably only buy a water heater about once per decade, and you may be in a rush to get it installed before your next shower, it’s easy to be confused about what to look for in a new one.

Size is the first question. If your family runs out of hot water frequently, a larger water heater is a wise choice.

The average three-person family with a three-bedroom home can get by with a 40-gallon tank. Larger families or homes may need a 50-gallon unit, and single people or couples could probably get by with a 30-gallon tank.

If the leak is minor and there’s time to shop, be sure to check the yellow energy labels on water heaters to find the most efficient unit. Gas heaters are usually two to three times cheaper to operate than electric models.

Better quality water heaters have two anode rods to delay the rusting process, and they’re made with a thicker surface on the inside to resist corrosion. Less expensive water heaters may not last as long, but if your plans are to move in a few years, a cheaper model may make more economic sense.

Expect to pay around $250 for a 40-gallon water heater with a five-year warranty. A higher-quality unit with a longer warranty will cost about $375.

Installation costs vary depending on how hard it is to access the water heater. It should include hooking up new water and gas couplings, checking the vent system on gas heaters and attaching metal brackets or plumber’s tape to make the water heater earthquake safe.

Insulate

A water heater that feels hot when you touch it is losing heat. If it doesn’t void your warranty, cover the tank with an insulating fiberglass blanket, which is available in a kit at home centers. On a gas unit, be careful not to cover the top of the tank or to block the airflow to the burner at the bottom.

You may want to have the heater installed on top of a metal tray so that future leaks can be discovered before they hit the floor.

When a plumbing fixture, such as a bathroom sink, is far from the water heater, a lot of water must run through the pipe before hot water reaches it. Insulating the pipes that carry the hot water from the heater to the fixture can reduce the heat loss. It’s especially important to insulate any pipes that run through unheated areas.

Also consider having a plumber install an “instant” water heater near the fixture. It’s expensive and requires a special electrical circuit but may be a good choice in a restricted-water-use area.