Remove the old water heater by turning off all valves and draining the
water. If you're replacing an old hot water heater, you must cut the
pipes away, turn off every valve, and drain it of water. To remove an
old heater, do the following:
Turn off the cold water valve at the top of the heater.
Switch off the gas valve and turn off the electric supply to the heater at the circuit breaker — watch the pilot light go out to ensure no more gas remains.
Attach a hose to the drainage pipe and let the water flow into a drain.
Unscrew and disconnect the vent shaft at the top of the heater.
Remove any remaining unions with a pipe wrench or tubing cutter.
Place the heater on a lifting trolley or forklift, place it in your
truck, and bring it to the proper disposal facility. Consider hiring a
removal service if you lack the ability to carry it yourself.
Place the new heater on top of blocks and align it with the pipes. Lift
the heater onto cinder blocks or concrete blocks with a lifting trolley
or a forklift — use blocks that are the same size placed directly next
to each other to minimize the risk of the heater falling. Align it as
best as you can with the water and gas pipes, as you can rotate the
heater later on if it isn't quite perfect.
that the water heater does not make contact with the ground, even while
you are setting it up, as it could alter the integrity of the heater's
exterior, damage low pipes, and make the heater less effective overall.
Attach a new temperature and pressure relief valve. Grab the
temperature and pressure relief valve, which looks like a faucet with a
valve on top with a small hose-like pipe coming out of the bottom. Screw
it into the temperature and pressure relief hole, which looks like a
large circle with an input slot, and apply teflon tape if necessary to
Use a pipe wrench to get the temperature and pressure relief valve fully tightened. Opt for a copper version of the relief valve to keep the lines clean, as copper has antibacterial properties.
Solder new copper adapters to the water intake on top of the heater.
Using 6 in (15 cm) copper pipes, solder a new adapter to one open end of
a pipe to make it fit correctly into the water intake on top of the
heater. Use a pipe wrench to secure the connection. The hot water output
should have a red ring around it, while the cold water intake should
have a blue ring.
If your area has particularly hard water
or if your city requires it, attach a plastic lining "nipple" to the top
of the intake valve to further regulate the water quality.
Attach the water lines to the top of the heater. Align the copper pipes
extending from the intake valve on top of your new heater with the
water pipes coming from the ceiling or wall. Then, solder the pipes
together with copper couplings.
If they don't line up, solder elbow joints to the water heater's copper pipes to get them to connect seamlessly.
Reattach the vent shaft over the draft hood on top of the heater. Shove
the draft hood tightly over the vent and secure it to the heater with
3⁄4 in (1.9 cm) screws. The vent should be at least 1 foot (0.30 m) high
before it bends, so re-adjust the vent as needed.
It is best to pre-drill the holes into the draft hood so you can align the vent shaft with the draft hood easily.
Reconnect the gas line to the gas valve. Coat the ends of a steel pipe
with pipe joint compound and screw one side into the gas valve. Then,
align it to the tank and connect it to the gas supply. Use two wrenches
to reduce the stress on the gas valve, keeping one on the valve itself
to steady it and one to do the turning.
Use plastic coverings to secure the union of the gas valve and the gas intake.
Fill the new tank with water and test it for leaks by turning on a
faucet. Turn on the water at the main shutoff and leave the cold water
valve open. Turn on a faucet in a nearby room to hot and listen for the
heater to turn on. Then, look at every joint on the heater to make sure
there is no leakages. If you smell gas, turn off the gas valve and the
faucet, wait a few hours, then solder the connection. If you don't wait, you could spark the gas in the air.
Water leaks and gas leaks can be fixed by tightening the
connections or soldering the pipes. Turn off the valves and tighten or
solder the loose connection, then try again.
Turning on hot
water throughout the home activates the heater, even if the pilot light
is not on, so you are able to check the pipes for leaks much more
Light the pilot light per the heater's instructions and set it to 120
°F (49 °C). After you have checked for leaks and made sure your
connections are secure, light the pilot light of the heater and set the
heater's temperature to 120 °F (49 °C) according to the manufacturer's
instructions. Every heater has a different process, so follow the
manufacturer's guide to find the location and method of lighting the
The pilot light will generally be at the
bottom of the heater behind a removable panel, but again, check the
instructions that came with your heater to safely get it started.