Cleaning Hot Water Heater

Why cleaning water heater is important
Avoid problems with the clean parts

Cleaning hot water heater is as important as regular maintenance you are suggested to do by the manufacturer. A clean water heater and the environment where it operates is the first thing you should consider when troubleshooting hot water heater. And this is why you should use the tips provided here.


Regular maintenance with cleaning is especially important with the industry regulations and implementation of the flammable vapor ignition resistance, FVIR, as the dirty environment can significantly affect and reduce water heater performance. Some water heater parts have to be cleaned, from simple dust cleaning to removing sediments from a water heater tank or electric elements.


So how do you clean the inside of a hot water heater?

Required tools like vacuum cleaner, wire brush, flashlight, wrench, soapy water, are easy to find as they are part of the tools you are probably using on a daily or weekly basis.

Keep in mind that most of the repairs and maintenance should be done by the professional technicians. Before calling for help, here are some measures you can take yourself:

  • Keep the water heater clean, especially if you notice the drips from leaking water pipes.

  • Keep the space around the water heater clean from dirt, household cleaners, paint and flammable materials.

  • Before you perform any type of the maintenance, visual inspection of the external and internal components should be performed regularly.

Cleaning hot water heater is important, especially if there are spilled or leaked flammable liquids around. It is vital to have all the resources of flame, both pilot and the main burner, extinguished.

Cleaning gas water heaters

One of the most important steps when cleaning a gas-powered hot water heater is to clean the combustion chamber and burner elements. The main burner, pilot burner and flame arrestor have to be cleaned at the periodic intervals, not more than 6 months.

The air intake screen cleaning is also very important because the air, at the bottom of the water tank heater, is drawn in for gas combustion. Keep this area free of dirt and dust, and free from flammables, so the proper gas combustion won't be affected.

To clean the combustion chamber, burner assembly and flame arrestor, remove the burner assembly first. This is how...

the base of the gas water heater with the flame arrestor, filter...

emergency plumber

Cleaning the flame arrestor

The flame arrestor, as part of the FVIR technology keeps the flame inside the combustion chamber. It is very important to keep the flame arrestor maintained.

If there is a problem with the insufficient combustion air, one of the solutions is to clean the flame arrestor. This is how:

  • Remove the access door.

  • Remove the burner assembly.

  • Inspect and clean the flame arrestor using a stiff brush. Use the compressed air or vacuum cleaner with blowing capabilities to clear the dust or debris from the flame arrestor. Once you are done with blowing down and through the arrestor ports, use the vacuum below the flame arrestor to collect the dirt.

  • Reinstall burner assembly.

  • Reconnect feedline, pilot and thermocouple.

  • Bring the access door back.

  • Resume operation.

If your water heater is equipped with the additional screen against the lint, dust and oil, called LDO screen, located at the base of the heater, it has to be cleaned or washed regularly. This area is important as all of the combustion air enters the heater in there. Air intake screen cleaning will improve the performance and save you a costly service call.


How to clean a water heater main burner

The main burner is subjected to the carbon deposits, also known as sooting. If the burner is dirty or clogged one of the solutions is to use a soap and hot water to clean it. Or simply follow the steps below:

  • Turn the control knob on the gas valve to the OFF position.

  • Remove the inner door assembly.

  • Disconnect the main burner feed line, pilot assembly and thermocouple.

  • Remove the burner assembly from the combustion chamber.

  • Inspect the burner surface, burner ports and remove the dirt and debris.

  • Remove the main burner orifice, inspect and clean it.

  • Next, wipe clean the pilot assembly (or electrode) from dirt as it might prevent the ignition spark. If there is rust accumulated on the surface, use a sandpaper to remove it.

Before installing the gas unit and connecting a vent to the chimney, make sure that chimney passageway is clear and free of obstructions, especially if it was previously used for solid fuel appliances or fireplaces.

Why cleaning hot water heater

There are many problems associated with the dirty and clogged heater elements. The following problems will be easily prevented if cleaning hot water heater regularly.

  • Main burner or pilot will not ignite

  • Burner flame is yellow

Reason: Pilot line, burner line or orifice is dirty and clogged.

  • Smoking and carbon formation

  • Combustion odors

  • Sooting

  • Slow hot water recovery

  • Burner flame floats and lifts off ports

Reason: Air supply or flue pipes are obstructed, clogged burner.

If using the electric water heaters, sediment buildup at the tank bottom may create the annoying noise, and if left there, without cleaning, will cause the permanent tank failure.

As the sediments can build-up on the heating elements, for cleaning sediments from a water heater elements follow the instructions to drain, flush and clean it, or if necessary to replace it.


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(All pictures are courtesy of AO Smith)

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