Our house isn’t haunted, but just try to tell that to our guests. “Our water heater makes funny noises,” I warn. First-timers respond with a smile and nod—and forget.
“What was that noise?” is the predictable next-morning question. Some say it sounds like a big clumsy man on the roof. Children trend more toward a “monster in the wall” theory.
It’s the water heater. It makes funny noises. I’ve never understood why, and as long as hot water keeps coming through the pipes at the right time, we’ve just learned to live with the loud rumbling.
Handyman Jim Brown says we’re lucky. The thing should have failed by now, given the hardness of the water in our area. At the very least, we’ve been spending way too much money to keep Big Belch running.
The problem is sediment. When the water containing high levels of calcium and minerals is heated or frozen, the dissolved salts precipitate out. You‘ll see it in the bottom of a glass that contained ice and was left undisturbed for several hours. It’s the residue left in a pot after boiling water. Your water heater is like a big tea kettle. Over time, you’ll hear your water heater rumbling when it’s heating. It isn’t about to blow up, but it’s now much less efficient.
Mineral deposits can cause several problems. In all cases, they take up space so your water heater holds less water. After cutting them open, one repairman told me he’s seen water heaters with deposits two feet deep—40 percent of the tank capacity displaced by sediment! Research shows that for every 1/2 inch of sediment on the bottom of a gas-fired water heater, 70 percent more fuel is required to heat the water.
Manufacturers recommend that we regularly drain and flush our water heaters to get rid of the sediment. How often depends on the mineral load in your water, the amount of hot water used, and whether a water softener is part of your system.
To drain, Jim says to first turn off the power. If your water heater is gas-powered, twist the dial on the thermostat from the “on” position to “off.” If it’s electric, flip the circuit breaker off at the service panel that controls the water heater or flip off the main breaker. Next, shut off the cold water supply by twisting the water valve (located atop the heater) clockwise until it stops. Then attach a garden hose to the drain valve at the base of the heater and run the other end of the hose into a light-colored bucket in order to view the sediment.
Open the drain valve and turn the cold water supply back on to flush out the sediment. Be careful; the water coming out is hot! The water first exiting the heater carries the most sediment. When water runs clear, shut off the drain valve, detach the hose and turn the power back on.
Caution: If your water heater is gas-powered, call the gas company for specific instructions before attempting to re-light it yourself. In many cities, they'll come to your home and do that for you, no charge.
The owner’s manual that came with your water heater will give specific instructions for routine cost-saving maintenance.
