How to Replace a Water Heater Fast and Easy | DIY Tips

Learn why, when and how to replace a water heater in a few easy steps. The article is recommended for the owners of an old electric or gas water heating unit that is rusty and is about to leak if the tank is full of sediments and efficiency is very low, and is beyond repair, or simply planning to install a new one. Check out when is the best time and what needs to be done. Here are some tips for an easy replacement.

Most of the tank-type electric and gas water heaters have a warranty from 6 to 12 years and with the regular maintenance can last approximately 10-15 years. So the question is; should you wait until the unit dies or is it better to replace a water heater before something happens and damages your property (like flooding) or affect your health.

What you should know before replacing a water heater

Rheem gas water heaterRheem gas water heater

When the water heater leaks in an unfinished basement or garage it is not as dangerous as if it is installed in the attic. The first signs of a problem that might lead to the replacement are the puddle of water at the bottom and around the heater, rust from the hot water faucet, corrosion on the tank and connections and low efficiency due to heavy sediment buildup.

Common problems that can be easily fixed

Also, some issues are common and require component replacement, cleaning or simply tightening the wire connections. Here are the examples of the problems that can be repaired but do not require water heater replacement:

  • Rotten egg smell. Rotten egg odor happens when there is bacteria growth inside the tank. Rotten egg odor caused by the sulfur bacteria can be found in any water heater brand. If the rotten egg smell is coming from the hot water tap only, the problem is in the water heater.
  • No hot water. One of the reasons for no hot water is the broken dip tube, so water instead of going to the bottom of the tank where it gets heated, it goes right to the tank's upper part and from there through the hot water outlet and further to the fixture.
  • If the pilot doesn't want to light up, the thermocouple might be broken, but if the problem is with the FVIR and flammable vapors, then the heater has to be replaced.
  • If the gas burner does not ignite, check the thermostat or the igniter.
  • If the ECO (Energy Cutoff) switch was activated.
  • Smoking and carbon formation - the thermostat might need replacement.
  • Sediment and limescale buildup can be cleaned, but if it is really bad (heavy) and cannot be removed, then the only solution is to replace a water heater.

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How to prevent early water heater replacement (examples)

Regular maintenance, which includes inspection and anode change, TPR testing, sediment flushing, or vent, and combustion chamber cleaning will prevent premature failure of the water heater and will get you several more years of the efficient water heating.

If you find a puddle of water underneath the unit, check if the pressure and temperature relief valve is releasing some water due to the temperature and pressure buildup. Regular testing will ensure that the TPR valve is still operational and high pressure inside the tank won't affect it.

Bulging might also happen, which is the result of the extremely high pressure inside the tank, and it can lead to deformation and potential cracks in the metal tank. More water will be released as the crack opens when water is heated and gets smaller when the metal contracts and the water cools down. This is why an expansion tank must be installed in closed-loop heating systems.

High pressure within the municipality piping and home plumbing might also lead to a loose fitting connection and potential leaks. Installation of the water pressure reducing valve can fix this problem.

If the unit's breaker switch keeps tripping off, you should inspect and test the heating elements and thermostats, they might be broken, or you might need to replace a weak breaker.

The unit should be drained at least once a year. If not, sediment and other deposits will build up and coat the elements making the heater work less efficiently and produce rusty water.

Another suggestion from manufacturers and professionals is to install a drain pan with an alarm if it is leaking over the top.

When is the right time to replace a water heater

You must replace a water heater if it was flooded, or parts, such as the gas valve, pilot assembly or main burner have been submerged in water.

Every tank-type gas water heater today is equipped with the FVIR system, which is designed to reduce the risk of the accidental ignition of the flammable vapors (gasoline, for example). Water heaters that are subjected to this problem will show the discoloration of the flame arrestor, and that is the sign when the unit needs replacement.

As mentioned above, there are many reasons for an early water heater replacement, but the main reason against is of course money. Follow the suggestions found here to prevent any accidents to the property because of leaking or spending money on a plumber for frequent repairs.

If your water heater is old, and you find a great deal, go for it. Keep in mind that after 10 years or so, your heater is old while new ones are more advanced and efficient, so you might want to consider a replacement. Another option is to go with tankless since they last at least 20 years, there are no storage water tanks, and every component can be replaced.

Required tools

  • Pipe wrench
  • Adjustable wrench
  • Screwdrivers
  • Soldering torch
  • Tube cutter or hacksaw
  • Multimeter
  • Wire stripper
  • Teflon tape
  • Pipe joint compound

How to remove a water heater (gas and electric type)

Shut the unit off. Turn off gas on the main gas valve supplying the water heater, electricity on the electrical breaker panel and water on the main shut off valve.

Drain. Connect one end of the garden hose to the drain valve located at the bottom of the heater and the other end to the outside drain. Empty the water heater completely. More about draining here.

Disconnect. If the water heater was connected to the plumbing with the copper pipes, you would have to straight cut the pipes right above the shut-off valve, and if the flexible connectors or galvanized pipes were used, simply unscrew the fittings.

Remove the vent pipe. Remove the vent pipe from the vent hood (gas type). If the gas unit is atmospheric just remove the screws using the screwdriver.

Disconnect the electrical wires from the junction box (electric type).

Disconnect a gas line, by unscrewing the connection using the pipe wrench, but be careful not to damage.

Remove the heater. Keep in mind that the tank-type water heater might be heavy, so call for the assistance and use the dolly cart.


Location. Put the new water heater in place providing enough clearance on all sides for ventilation and fresh air intake for combustion. If a water heater is installed in the area with hard water, that water must be treated (water softener) and may require frequent flushing.

Connections. Connect a water heater to a house plumbing using the flexible copper connectors or rigid copper. You might have to install plastic lined nipples.

Connect the electrical wires.

Reconnect the gas line. Be careful not to damage or dislocate the gas valve. Apply the piping compound to the threads of the black pipe and tighten the gas valve to it.

TPR valve. Make sure the TPR valve (temperature and pressure relief valve) is correctly installed. Attach the discharge pipe from the TPR valve to the proper drain.

Venting. Reconnect the vent pipe and make sure there is no leak from the draft hood. Make sure that new gas water heater receives plenty of fresh air for proper combustion.

Fill up the tank. Open the fixture while filling up the tank with cold water. This will bleed air out of the system. Water should flow freely from any tap.

Power up the heater. For gas models, light the pilot light following the instructions given by the manufacturer, and adjust the temperature on the thermostat. For the electric type, set the thermostat between 120 and 140 F.

Notes: During the removal and new installation, the manufacturer instructions, guidelines and plumbing codes must be observed. Check all the connections for leaks, especially gas. Fill the sponge with a mixture of dishwashing soap and water in a ratio of 50:50 and apply to the fittings. If it bubbles, there is a leak, which must be retightened or reconnected.

Again, before replacing the water heater due to the problem, try to fix it first, you might save lots of money. You can use this troubleshooting guide and check out the most common problems and instructions on how to fix them. Maybe something simple is the reason for the unit's failure.

In this video you can find some interesting tips:

According to the manufacturers, and to answer the common question "how long does a water heater last?", the life expectancy of the water heater is from 10-15 years and with the regular maintenance you could extend its life for a few more years. But eventually, the unit will stop producing hot water, corrode and start leaking.


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