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When Winter Has Passed, Be Sure You Address These Two Important Furnace Cleaning Tasks

When spring awakens after a long winter's nap, the last thing on the mind of most homeowners is their gas furnace. After all, no one wants to be in a basement or cramped attic when they can be outside enjoying the warmer temperatures. However, before you put on that short-sleeved shirt and head for the yard, remember your gas furnace needs some attention when it is turned off for the last time until fall or winter. Below are two important cleaning tasks you should address when the winter is done:

What needs to be cleaned

Even though natural gas is clean burning, there are still opportunities for soot or other combustion products to appear inside your furnace and connected components. Two specific areas need your attention: the flame sensor and gas burner tubes. Both are particularly prone to accumulating combustion products during use, and both can cause your furnace to run poorly or even cause damage. Below is how you can check and clean the flame sensor and gas burner tubes:

Flame sensor

Furnaces use flame sensors to determine when the blower should cycle on and off. If the sensor becomes dirty or charred, it won't be able to detect the presence of a flame, and your unit will fail to function properly. Fortunately, cleaning the flame sensor is an easy task with most gas furnaces:

  1. Shut-off the power - many furnaces have a separate power switch in close proximity to the unit. Your furnace may also be isolated on its own electrical circuit; if so, simply flip the appropriate breaker switch into the 'off' position.

  2. Remove the access cover - a thin, metal cover protects the internal components and prevents accidental contact with an open flame. The cover should slide or pull free from the furnace, but check your owner's manual if you have difficulty.

  3. Locate the flame sensor - the flame sensor will be located near the gas burners; it will consist of a thin metal probe extending from a ceramic base and will be attached to the electrical panel by a wire.

  4. Remove the flame sensor - the sensor will be mounted with a couple of screws, so remove them and pull the sensor from its mount. You probably don't need to unplug the sensor from its panel unless it needs replacing.

  5. Clean the flame sensor - use a piece of very fine grit sandpaper to clean the sensor. Be careful not to remove too much material; just sand enough to remove deposits from the metal. Use a cloth soaked with rubbing alcohol to remove any remaining residue.

After you have cleaned the sensor, re-install it, replace the cover and turn on the power by following the above steps in reverse.

Gas burners

The gas burners should also be cleaned every spring. The burners are long, cylindrical tubes that are perforated; these holes, or jets, are where the gas escapes and is ignited. If the jets become clogged with soot or other deposits, then the furnace will heat inefficiently, and it will cost you more to heat your home. Here is how you can clean the burners yourself:

  1. Turn off the power and remove the access cover as detailed in steps 1 and 2 above.

  2. Remove the burner tubes – you should see the ends of the burner tubes when you remove the cover. Most tubes can be removed by simply pulling them out or by turning them slightly while pulling. If you have difficulty, reference the owner's manual for assistance.

  3. Clean the burner tubes – inspect the tubes for clogged gas jets and signs of corrosion. Use a needle to push out any accumulated materials inside the jets, and scrub the burners with a firm-bristled brush. If necessary, soak the tubes in a solution of hot water and a grease-cutting dish washing detergent to loosen stubborn deposits. Just be sure to thoroughly dry the tubes before replacing them.

  4. Replace rusted burner tubes – if any of the burner tubes show signs of extensive rusting, then you should replace them with new tubes. Rusted tubes can crumble during use, and this could cause a dangerous flare-up or damage your furnace.

Reinstall the burner tubes and access cover by working through the above steps in reverse order.

If you need help with any of these steps or with other maintenance on your heater, contact a local HVAC company like Comfort Experts.