Weekly
Column This
Is A Hammer
By
Samantha Mazzotta
It’s
Time to Check Furnace’s Pilot Light
Q: A friend told me that the
pilot light on my gas heater needs to be cleaned.
How do I do this? — Taylor D., Anniston,
Ala.
A: In a forced-air gas furnace,
the pilot light is the item everything else
depends on. Not only does it light the gas
flowing through the burners, but its efficiency
can save money and improve the quality of the
heated air entering your home. So, inspecting and
adjusting the pilot light mechanism is an
important task at the start of the heating
season.
Two elements play a role in the
proper functioning of a heater’s pilot
light: the pilot jet, which controls the amount
of gas that exits the gas line, and the
thermocouple, which creates an electrical charge
from the heat of the pilot light and keeps the
flame burning.
Check the pilot light by
removing the main furnace access panel. If you
can’t see it, turn off the gas supply to the
pilot and wait 10 minutes for the control unit to
cool down. Then remove the pilot cover and
relight the pilot, following the instructions on
the control housing or the access panel.
A good flame is steady, blue at
the bottom and yellow at the tip, and it should
cover one-half inch of the end of the
thermocouple (a metal rod positioned at the mouth
of the pilot light). If the flame is all blue and
barely touches the thermocouple, it is too weak;
if the flame is noisy and "lifts off"
of the pilot, it’s too strong. Use a small
screwdriver to turn the pilot adjustment screw,
located either on the control housing or the gas
valve.
If the pilot light just
won’t stay lit, the thermocouple may be the
culprit. The thermocouple is attached to a coil
of copper tubing that is thinner than the gas
supply line (silver/metallic tubing). To replace
this part, turn off the gas supply and use an
open-ended wrench to loosen the thermocouple
tube’s fitting from the control housing.
Then, unscrew the thermocouple from the pilot
housing. Install the new thermocouple.
Once the pilot light is
healthy, turn the heater on and inspect the
burner flame. It should be blue to bluish-green
with occasional streaks of yellow. Put on
protective gloves and adjust the air shutter at
the end of the burner tube so the flame burns
correctly.
|