Invest $75 now and save hundreds in the years to come...
1. TURN OFF power to heating/cooling systems at the main
panel. Mark wires with a tab (or tape) and letter that represents the
terminal; unscrew them. Remove and discard the old thermostat. 2. LEVEL
the new mounting plate in position and mark the mounting screw holes. Drill
3/16-in, holes, insert drywall anchors and screw the plate to the wall.
3. SCREW wiring to terminals on new thermostat using labels
as reference (strip wires back if needed). Hook wires up to same terminals
on new thermostat. Snap thermostat to mounting plate.
You can reduce your home’s heating and cooling costs by about 15 percent
with a programmable thermostat. It automatically keeps the temperature
at a comfortable level when you’re home, but switches to an energy-saving
level when you’re away or asleep. Programmable thermostats are available
from home centers and hardware stores for $25 to $100. The higher-priced
models provide more programming options.
Programmable thermostats will work with most gas or oil furnaces, and central air conditioners. However, heat pumps, electric baseboards and a few other systems require special features. Read the package to make
sure the programmable thermostat you buy is compatible with your heating and cooling system. If you’re unsure, call your local utility or a heating and cooling contractor listed in your phone book or Internet.
PROGRAMMABLE THERMOSTAT OPTIONS. When shopping for a programmable
thermostat, select one with the options that are right for you.
Some contain a time-to-change-the- filter light or low-battery
indicator. Others have keypad lock features to prevent tampering,
or contain mechanisms that automatically reset your temperature
settings when moving between heating and cooling seasons.
Energy-Saving Q and A
Setback thermostats save money
Q: We’ve always used a setback thermostat to lower the temperature
at night and during the day while we’re gone. My son-in-law
says we’re not saving anything, claiming the amount of energy
used to reheat the house is far greater than if we left the
thermostat set at a constant temperature. Who’s right?
A: You’re right. Your son-in-law holds a common mis conception,
which has been dispelled by years of research and numerous studies.
The fuel required to reheat a building to a comfortable temperature
is roughly equal to the fuel saved as the building temperature
drops to the lower setting. You save fuel between the time that
the temperature stabilizes at the lower level and the next time
the heat is needed. So, the longer your house remains at the
lower temperature, the more energy you save.
Studies show you can cut costs by as much as 20 per cent by
lowering your thermostat 5 degrees F at night and 10 degrees
during the day when no one is home. The same goes for raising
the temperatures by that same amount when using air-conditioning
in warmer climates.
DONT USE DUCT TAPE ON DUCTS. Studies have shown that cloth-backed
duct tape is one of the worst materials you can use for sealing
leaky ducts; it degrades quickly. Use aluminum tape, mastic or
other adhesive specially approved for sealing ducts.
Remove the old thermostat as shown in Photo 1. If your old thermostat
contains mercury, you’ll see a small glass tube with a shiny silver ball
inside. Mercury is toxic. Take this type of thermostat to a hazardous-
waste disposal site.
There will be anywhere from two to five wires hooked up to the old thermostat.
Label the thermostat wiring with marking tabs using the letters on the
old screw terminals as reference. If your new thermostat doesn’t come
with marking tabs, use masking tape.
Clip a clothespin to the cable so it doesn’t slide down inside the wall
cavity, and mount the new wall plate (Photo 2). If the thermostat has
back-up batteries, insert them before wiring the new thermostat (Photo
The thermostat may need to be configured to your heating system. It
may come preprogrammed, but to maximize savings, set it up according
to your schedule. Consult the instructions that come with the thermostat
for system adjustments and programming. You won’t save energy if the
thermostat isn’t programmed correctly.
Energy-Saving Q &A
Duct tape: not for ducts
Q: What’s the best way to seal leaks in my ductwork? Duct tape
seems to deteriorate pretty quickly.
A: It’s one of those goofy ironies that duct tape really doesn’t
work well on ducts. In fact, the Model Energy Code bans the use
of duct tape for sealing ducts. Instead, use the aluminum tape
you’ll find with the vents and ducting home centers. This tape,
which costs about $20 for a large roll, works on most ductwork
connections as long as the metal is fairly clean.
Aluminum tape won’t work where a round trunk line
connects to rectangular ductwork. For these joints, use either
pure silicone ($3 to $4 a tube) or a sealant specifically designed
Fall Furnace Tune-up
Simple maintenance pays big dividends for comfort, efficiency and safety.
1. FLIP the electrical power switch to OFF. Remove the
combustion chamber door by lifting up and pulling it out, and remove
the burner cover (if you have one). It’s usually held in place by two
screws. 2. TURN the power switch on and activate the burners by turning
up your thermostat. Inspect the burner flames. The flames should be fairly
even and blue. Yellow flames indicate dirty burners. (Don’t breathe on
the flames because the extra oxygen will also make them turn yellow.)
Don’t adjust the burners yourself. Call in a pro.
When it comes to furnaces, an ounce of prevention truly is worth a pound
of cure. To help you avert the hassle of your furnace dying or simply
not putting out enough heat—just when you need it most—we’ll walk you
through a series of simple steps that will keep it in tip-top shape.
The entire maintenance operation takes less than three hours and costs
only a few dollars—pretty cheap insurance.
Here, the focus is on natural gas and propane-fueled furnaces. The maintenance
tasks involving the blower chamber also apply to oil furnaces; however,
oil furnace combustion chambers are very different and should only be
worked on by professionals.
(Heat pumps, on the other hand, work more like a central air conditioner
than like a furnace, so we won’t deal with them here.)
Routine furnace maintenance and cleaning don’t require special skills.
If you’re handy with a few basic hand tools, you can do it. You won’t
be doing tricky or potentially dangerous stuff like adjusting the gas
burners. Leave that for a pro. See “Symptoms That Call for a Heating
Professional,” below for more details.
We should warn you that your furnace may look somewhat different than
the one we show here. If you don’t feel confident about taking some of
the steps shown, skip them. and pay close attention to the safety precautions
in this article, in your furnace service manual (if you can find it!) and posted on your furnace.
Even if you follow our maintenance steps, call in a heating professional
for a thorough furnace checkup at least every three years. (Look/search
for under ‘Heating’ in the Yellow Pages or Internet).
TIP: f you’re faithful about changing
your filter, you won’t have to clean the blower.
Gas furnace details--A forced-air furnace
has four main sections: (1) the blower chamber; (2) the combustion chamber;
(3) the return duct; and (4) the supply duct. When your thermostat calls
for heat, the burners will kick on and begin to heat up the heat exchanger.
The heat exchanger contains all the dangerous gases produced by combustion and vents them through the exhaust stack. When the heat exchanger gets
hot enough, the blower starts. The blower pulls cooled air through the
return duct, passes it over the warm heat exchanger and returns the warmed
air to the rooms.
Furnaces vary quite a bit in design, so yours may be somewhat different
from this illustration. If confused, consult your service manual or a
3. TURN OFF the power switch again and shut off the gas
by giving the valve a one-quarter turn (see ___ above for approximate
gas shutoff valve location). Vacuum the burners and the furnace base.
To get at the back of the burners, tape a 20-in. length of 1/2-in, drain
line to your vacuum hose. Vacuum every where you see dust. While everything
is open, use a flashlight to look for signs of soot (fine black powder),
which often indicates poor combustion (see Symptom 5 below). Lift off
the lower door (blower door) and vacuum the blower compartment. 4. REMOVE
the blower (also called a squirrel cage) in order to clean it. If you
have a control panel in front of the blower, two screws will loosen it and you can let it hang. Next, using a 7/16-in, socket and ratchet, remove
the two bolts that hold the blower in place, then gently lift it out.
5. CLEAN the blower blades thoroughly with a vacuum and small brush. Take care not to stress the wiring or disturb the counterweights
that will be on the fan blades. If you can’t clean the blower thoroughly,
don’t clean it at all; you could throw it off balance. 6. CHANGE the
furnace filter every one to three months. A $1 fiberglass filter will
adequately protect the blower and blower motor. If you want to install
a more expensive, high-efficiency filter, check the owner’s manual for
the manufacturer recommendations. High-efficiency filters can restrict
the airflow, strain the blower motor and make your furnace less efficient.
If you want cleaner air, the best option is a separate air-cleaning system.
Carbon monoxide alarm
INSTALL A CARBON MONOXIDE ALARM on each floor. If you already
have these alarms, test them. Carbon monoxide is an odorless, co1orless
gas sometimes produced by oil-, gas- and wood-burning appliances (furnaces,
stoves, fireplaces, etc.). If this gas spills into your home in high
enough concentrations, it can be fatal. Plug carbon monoxide alarms into
electrical outlets or directly wire them to the electrical system. They
cost about $40. Do not install them in utility rooms, garages, kitchens
7. BLOW dust off the pilot. Direct air to the exact spot
by blowing through a drinking straw. A dirty pilot can cause the flame
sensor (or thermocouple) to get a false reading that the pilot isn’t
lit Some newer furnaces have hot surface igniters instead of pilots and electronic igniters. (Note: One burner was removed for clarity.). 8.
THE FLAME SENSOR occasionally becomes coated with residue and will prevent
your furnace from lighting. Remove it by pulling it down out of its bracket.
Lightly clean the surface with fine emery cloth and slip the sensor back
into its bracket.
Caution: While working on your furnace, do not remove
burners, stick anything into the pilot orifice or make adjustments. Misaligned
burners can pose a serious hazard by allowing build up before the burner
ignites, causing a flash fire. Poking a sharp object into a pilot can
widen the orifice, turning the pilot into a flamethrower.
TIP: If your furnace has a standing pilot (a pilot that burns all the
time), turning off the gas to the furnace when the heating season is
over will save you as much as 5 percent per year on your gas bill. To
relight the pilot, consult the instructions on your furnace’s gas valve.
9. HOT SURFACE IGNITERS are the most common ignition system
on furnaces being manufactured today. They take the place of standing
pilot Lights and electronic igniters. Clean the dust off the hot surface
igniter by leaving the igniter in place and blowing air through a straw.
This part breaks very easily; don’t even touch it. In fact, when you
replace the furnace doors, do so gently to avoid breaking the igniter.
10. THE BELTS on belt-driven blowers need occasional
adjustment or replacement. Inspect the drive belt for cracks or frayed
areas. A new belt costs about $5. When you install the new belt, tension
it so it deflects 1/2 to 3/4 in. 11. SOME OLDER FURNACES have two motor
bearings and two blower shaft bearings that require annual oiling. Clean
around the oil caps and remove the caps. Apply two to three drops of
Lightweight machine oil and replace the caps. Don’t over lubricate!
12. IF YOUR FURNACE heating ducts also serve as air-conditioning
ducts, they may have dampers that require adjusting for seasonal changes.
The seasonal settings should be marked. Two- story homes often have separate
supply trunks to serve the upstairs and downstairs. To send more warm
air downstairs (winter setting) or more cold air upstairs (summer setting),
adjust the damper handle on each supply trunk.
13. SEAL leaky ducts especially return air ducts with special metal
tape (available at home centers for $12) or high- temperature silicone.
Then conduct the following backdrafting test to make sure the combustion
gases go up the flue: Adjust the thermostat so the burners come on. Hold
a smoking stick of incense beside the draft hood (Photo 14). The smoke
should be drawn into the hood. Also inspect the exhaust vent pipes on
your furnace and water heater (while they’re cool). White powdery residue
can indicate corrosion. Gently squeeze the exhaust stack with your hand.
It should be firm but slightly flexible. Call a heating professional
or plumber to fix all these types of problems.
14. TEST your gas water heater for backdrafting while your furnace is
off. Turn up the water heater thermostat until the water heater burner
comes on. After a minute or more, hold a smoking stick of incense or
match up to the exhaust stack. The smoke should be pulled into the stack.
Conduct the test with all exterior doors and windows closed and bath and kitchen fans running. If the vent doesn’t draw, call in a heating
specialist or plumber to find the problem. Turn the thermostat back down.
Symptoms that call for a heating professional
Symptom 1: Short cycling
When your furnace runs for only short periods (less than three minutes)
before shutting off, the problem is called short cycling. This happens
when the thermostat is out of adjustment or when the heat exchanger overheats and the burner automatically shuts off to prevent damage.
Symptom 2: Irregular flame
Properly functioning burners have fairly even rows of flames. If the
flames are uneven or lean toward the back of the furnace, call in a pro.
It could be a sign of dirty burners or a cracked heat exchanger.
Symptom 3: Odd noises or rumbling
While rumbling and popping aren’t cause for concern in a hot water or
steam heating system, they shouldn’t be present if you have forced-air
Symptom 4: Chronic illness
Frequent headaches or flulike symptoms can be a sign of combustion gases
leaking from a cracked heat exchanger or carbon monoxide leaking from
an exhaust stack. With these symptoms, have your heating system checked
out even if your carbon monoxide alarm remains silent.
Symptom 5: Soot deposits
Soot is a fine black powder that collects when combustion is incomplete.
Its presence may indicate that your burners need adjusting or that you
have a cracked heat exchanger that needs replacing.
Next: Cheap vs. expensive furnace filters
Prev: Heating Season: Introduction
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