By Matthew Robb
Special to the Tribune
Published April 1, 2005

John Murphy returned from work to his Mokena home last winter to find something of a mystery. The fogged-up windows and tropical humidity puzzled him, but it wasn’t until he heard a gushing sound that he realized what was up. His basement was flooding.

The culprit was his water heater. After rupturing and spewing its scalding contents, it became a runaway geyser that pumped out water as fast as the municipal utility could pump it in.

When the rising tide burned out his sump pump, a massive cleanup headache was inevitable. “We lost family photographs, furniture, a computer, maybe 200 prized LP albums and lots more,” he recalled. “Needless to say, my gas and water bills were quite high that month.”

It could have been worse. In 2001, a water heater rocketed through the roof of a Seattle video store, soared over a nearby Taco Bell and crash-landed 460 feet away. Elsewhere, gas units have exploded and demolished homes or silently leaked carbon monoxide that asphyxiated families.

“When water heaters fail, they can fail catastrophically– especially gas units,” said Home Inspector Will Decker, of Decker Home Services in Skokie.

Few malfunctions are so dramatic, but things can and do go awry. Prevention begins with routine water heater maintenance.

Think of your water heater as a combination boiler and Thermos bottle. Over time, mineral deposits in the water cover the tank’s bottom, making the unit work harder, which stresses the tank. A related problem is electrolysis. The hotter the water, the more chemically reactive. Given time, “it eventually begins attacking the tank’s internal ceramic lining,” Decker said.

Water heaters sometimes give subtle clues that things are amiss, such as pinhole leaks or odd noises. Other times, they rupture without warning. Industry experts cite an estimated 8- to 10-year life span, but neglected units die young.

Step 1: Drain the tank

Manufacturer guidelines vary, but most call for draining a water heater every six months or so. To drain, turn off your tank’s electricity or set the gas to “pilot.” Connect a garden hose to the drain valve at the base and place the discharge end into a sink. Close the tank’s cold water inlet valve. To break the water line vacuum, turn on the hot water in a sink somewhere in your home or flip open the temperature and pressure relief valve (or the T&P valve), remembering to place a bucket under the T&P valve’s drain tube. Empty the tank (note that the drain-down can take a while). Once the tank is empty, close the drain valve, open the cold water supply and allow the tank to fill. Once water comes out of the hot water faucet, the tank is full and your task is done. Turn the electricity or gas back on to heat the water.

Some manufacturers specify a thorough flushing. The instructions are similar to draining, but leave the cold water on, letting the pressurized water blast sediment from the tank until the water runs clear.

Home inspector Patrick Kelley, owner of P.X. Inspects in St. Charles, issues a big caveat. “If you drain your tank, do it regularly. If you don’t and it’s old, do not suddenly start.”

Decker agrees. “The rubber seal inside the valve could have deteriorated,” he said. “You might open the water valve and not be able to shut if off.”

Step 2: Check the T&P valve

Manufacturers equip tanks with an emergency relief valve that pops open whenever internal water pressure or temperatures reach critical levels. The resulting spillage is far from ideal, but an exploding tank is less so. Manually operate this valve annually to ensure it works, advises David Harrington of the American Water Heater Co. in Johnson City, Tenn. When doing so, stand clear of the valve, flip the lever open and release a bit of hot water through the drainpipe into a pan. Release the valve and make sure the water stops dripping. If defective, contact a service technician.

Step 3: Inspect

Check your tank’s anode rod every two to three years. This roughly 3-foot-long magnesium or aluminum pole is located inside the tank and screws into the top with a hexagonal bolt. Its job is to attract sediment that would otherwise corrode the tank. Replace per manufacturer directions. Harrington recommends annual inspections for leaks or obstructions in gas lines and the venting and air-supply system. If you’re unsure of how to do any of the maintenance tasks, it may pay to have a service technician assist you.

Keep combustibles away from your water heater. To reduce scalding hazards, do not exceed the tank’s 120-degree factory preset. If you have a gas unit, get a carbon monoxide detector.

For older water heaters, Kelley counsels prevention. “If your tank lasts 12 or 13 years,” he said, “you’ve got your money’s worth. Get a new one.”

For peace of mind, install an alarm system (about $90) that automatically shuts off the water supply when it detects a leak.

Some manufacturers detail different maintenance steps, so read your buyer’s guide or check the manufacturer’s Web site. If you take care of your water heater, it will take care of you. That’s good news on chilly mornings.

Copyright © 2005, Chicago Tribune