Basic maintenance checklist
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Photo 1: Check the pressure-relief valve
Place a bucket below the discharge
pipe and gently lift the lever on the
pressure-relief valve to test it.
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Open the drain valve slowly and let the water run until it's
clear and free of sediments. Caution: The water is hot!
Water heaters often work perfectly
for a decade or more without
any care, so they're easy to neglect.
But a few minutes of TLC once a year
pays off by extending the tank's life span
and maintaining your water heater's efficiency
First, test the pressure-relief valve located
on the top or side of the water heater
(Photo 1). This valve opens automatically
if the pressure inside the tank gets too
high. (Excess pressure can actually cause
the tank to explode.) If the valve doesn't
release water when you lift the lever,
replace the valve (sold at home centers and
hardware stores). Replacement is simple;
turn off the water, drain the tank, unscrew
the discharge pipe and then unscrew the
old valve. Wrap the threads of the new
valve with sealant tape and screw it in. If
your valve is several years old and has never been tested, it might leak after you
test it. In that case, replace the valve.
Next, close the shutoff valve on the cold
water supply pipe that feeds the water
heater. Then turn on the hot water at any
faucet to release the pressure inside the
heater's tank. Leave the faucet on until you
finish your work. If you have an electric
heater, turn off the power at the main
panel. With a gas heater, turn the gas control
dial to “off.”
Drain the tank to flush out sediments
that have settled to the bottom of the tank.
Sediment buildup shortens the life of your
water heater and adds to your energy bill
by reducing its efficiency. Draining 2 or 3
gallons of water is usually enough to flush
out sediments, but always let the water
flow until you no longer see particles in the
bucket. Caution: The water is scalding hot.
Don't worry about any gurgling or
groaning noises coming from the heater;
it's just air entering the system as water
drains out. If the drain valve won't close
tightly when you're done, drain the tank
completely, unscrew the old valve and
screw in a new one. To restart the
water heater, open the shutoff valve and
let the hot water run at any faucet to purge
air from the system. Then turn on the
power or relight the pilot.
Set your water heater's dial to
120 degrees F. If the dial doesn't
have numbers, check the water
temperature with a cooking thermometer.
increase sediment buildup and
the risk of scalding injuries.