Fall Furnace Primer - Part 1 of 2
weather does little to remind us that winter’s cold breath
will soon be upon us. While you’re in the basement unpacking
the Halloween costumes, take a moment to consider your furnace.
Check the Switches
While it is probably okay, it’s not a bad idea to stroll over to
your breaker panel and make sure the breaker marked “Furnace” is
on. If your A/C was on recently, you can rest assured the breaker is
okay. Then head back to the furnace and look for the switch that controls
the electricity to the unit.
Most furnaces have
a switch that looks like a light switch controlling the electrical
supply. In a new house, the switch is often on a wall or a support
about 6 feet above the floor, near the furnace. In an older house,
the switch is often on the basement ceiling, or high on a wall, near
the bottom of the basement stairs. This allows you to shut off the
furnace quickly in the event of an emergency, without having to get
near the furnace.
Now that you finally
know what that mystery switch is, check to see if it is ON. If not,
the heat will not come on no matter how high you set the thermostat.
It is embarrassing to write a $75 check for a technician to come
to your house and flip a switch.
time to focus on the two primary maintenance jobs for furnace owners:
the air filter and the humidifier. We’ll talk about the air
filter now and save the humidifier for the next issue.
When the outside air makes its way inside, pollutants like dust, dander
and spores are added to the air which has already been exposed to
urban car exhaust, smog, dirt and pollen. The result is a thick,
soupy haze…that is entirely normal. While most people aren’t
bothered by the usual level of air-borne particulates, some are more
sensitive, and everyone is affected if the level becomes excessive.
To remove many of the larger particles from the air, your furnace
is equipped with a filter.
Most filters are
simply screens of paper, metal or plastic mesh that allow air through
but trap most of the dirt. Some of these are thicker for more surface
area, and some have specially treated media. Electronic air filters
use electricity to electrostatically attract even smaller particles.
They have a metal cover, an on/off switch, and may have an operation
light. There are those that dispute the quality of the air cleaning
abilities of standard household filters. These people usually sell
high-end systems. For most houses the normal filters will do, and
if nothing else they help keep the furnace itself free of massive
Where is it?
The furnace filter is typically a one to two-inch wide slot (for conventional
filters) or a six to eight-inch wide slot (for electronic filters)
in the ductwork immediately beside the furnace air return duct. If
you don’t see such a slot, your furnace’s air filter
is accessed only by removing the furnace and/or fan compartment cover.
Turn OFF the switch to the furnace before removing any covers.
What do I do?
Once you have located the filter, pull it out to have a look. Turn off
the switch on the electronic air filter before opening the cover.
For a regular filter, if the mesh looks dirty and/or the unit is
more than 3 to 6 months old, throw it out (paper media or fiber glass)
or clean it (metal or plastic media). For an electronic filter, make
sure you turn off the unit’s power switch. There will be two
washable metal screens called pre-filters, then two electronic cells
looking like layers of metal plates. These can all be soaked and
washed, every one to three months. Careful of the fine wires running
down one side of each cell…they are easy to lose or break.
Regular cleaning of the air filter is important for your furnace
and your lungs.
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