Cleaning Forced-Air Furnace Humidifiers

By adding moisture to the air, the humidifier on your furnace can make your indoor environment feel much more comfortable. It's important, however, to keep the humidifier clean and free of molds and mineral deposits that would otherwise spread throughout the house on the furnace's airflow or reduce the humidifier's efficiency. Plan on cleaning your humidifier monthly.

A humidifier will likely be one of two types: a drum, which rotates a circular pad through a water tray; or a drip, in which water drips through a pad. Both work by transferring the moisture from the pad to the air flowing through the humidifier and into the house through the ductwork.

Cleaning a Drum Humidifier

First, shut off electrical power to the furnace, either at the furnace's switch or at the house's main electrical panel. If you can't do this, turn the thermostat right down to prevent the furnace from coming on. Remove any screws holding the humidifier's cover in place so that you can take off the cover. You'll be able to see how the circular pad runs through the water that sits in the tray beneath the pad. Ensure that the water is, in fact, soaking the pad.

How do I know if the water level in the humidifier tray is highenough?

Check your furnace owner's manual or the humidifier instructions(if it was an add-on). They often specify a depth for the water. They'll also specify how to adjust the water level to either increase or decrease it as needed, but look for an adjusting screw on the float that sits in the water tray.

With one hand on either side of the circular pad (the drum), lift it out. The pad is held in place by a plastic framework on either end that's secured either by a nut or a clip. Undo it so that you can inspect the pad. If it's especially dirty or stiff (which often happens if the humidifier hasn't been cleaned for a while), it's best to replace it. Otherwise, you can dip the pad in a bucket that contains 3 parts white vinegar to 1 part water. Also remove the water tray and clean it out using the same vinegar-water solution.

Put the circular pad back on its framework, and carefully replace the drum in the humidifier. Replace the cover, and turn the furnace electrical supply back on or return the thermostat to its normal setting.

A drum-type humidifier has a pad shaped into a circle, or drum, that rotates through water contained in a tray and then releases the moisture into the air.

Cleaning a Drip Humidifier

First shut off electrical power to the furnace, either at the furnace's switch or at the house's main electrical panel. If you can't do this, turn the thermostat down to prevent the furnace from coming on. Remove any screws holding the humidifier's cover in place so that you can take off the cover. You should see a tube that carries water into a tray that sits above the pad; disconnect the tube from the tray. This will allow you to pull out the tray, and then the flat pad.

The holes in the tray can clog up with mineral deposits; carefully scrape these away with an awl or screwdriver. If the pad is especially dirty or stiff (which often happens if the humidifier hasn't been cleaned for a while), or it's starting to disintegrate, replace it. Otherwise, you can dip the pad in a bucket that contains 3 parts white vinegar to 1 part water, twisting the pad to help loosen mineral deposits.

A drip-type humidifier features a tray that lets water drip through a flat pad, which then releases the moisture into the air.

Look at the humidifier to see where the drain hose connects to it to take excess water away from the unit. Remove the hose from the unit, and run cold water through it to get rid of mineral deposits that could build up and block the hose. Put the hose back on the unit and replace the pad, tray, and cover. Turn on the furnace's electrical supply or return the thermostat to its normal setting.

The only maintenance that electric heat registers n& is to be kept free of dust and dirt. If a heat register is damaged or dented, the fins inside the register will need to be straightened-but the register's wiring should also be checked for damage if this is the case, so call in a qualified service technician who's familiar with wiring and repairing these.

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