55
BURNERS
WARNING
HIGH
VOLTAGE
E
LECTRICAL COMPONENTS ARE CONTAINED IN BOTH
COMPARTMENTS.
T
O AVOID ELECTRICAL SHOCK, INJURY OR
DEATH, DO NOT REMOVE ANY INTERNAL COMPARTMENT COVERS
OR ATTEMPT ANY ADJUSTMENT.
C
ONTACT A QUALIFIED
SERVICE AGENT AT ONCE IF AN ABNORMAL FLAME
APPEARANCE SHOULD DEVELOP.
Periodically during the heating season make a visual check of
the burner flames. Turn the furnace on at the thermostat. Wait
a few minutes since any dislodged dust will alter the normal
flame appearance. Flames should be stable, quiet, soft and
blue with slightly orange tips. They should not be yellow. They
should extend directly outward from the burner ports without
curling downward, floating or lifting off the ports.
Check the burner flames for:
1. Stable, soft and blue
2. Not curling, floating, or lifting off.
Burner Flame
TEST EQUIPMENT
Proper test equipment for accurate diagnosis is as essential
as regular hand tools. The following is a must for every service
technician and service shop.
1. Dial type thermometers or thermocouple meter
(optional) - to measure dry bulb temperature.
2. Amprobe - to measure amperage and voltage.
3. Volt-Ohm Meter - testing continuity, capacitors, and
motor windings.
MAINTENANCE
4. Inclined Manometer - to measure static pressure,
pressure drop across coils, filters, and draft.
5. Water Manometer (12") - to test gas inlet and manifold
pressure.
Other recording type instruments can be essential in solving
abnormal problems, however, in many instances they may be
rented from local sources.
Proper equipment promotes faster, more efficient service
and accurate repairs resulting in fewer call backs.
HEATING PERFORMANCE TEST
Before attempting to diagnose an operating fault, run a heating
performance test and apply the results to the
Service Problem
Analysis Guide.
To conduct a heating performance test, the BTU input to the
furnace must be calculated.
After the heating cycle has been in operation for at least fifteen
minutes and with all other gas appliances turned off, the gas
meter should be clocked.
To find the BTU input, multiply the number of cubic feet of
gas consumed per hour by the heating value of the gas being
used. (The calorific value of the gas being used is found by
contacting your local utility.)
EXAMPLE:
It is found by the gas meter, that it takes forty
(40) seconds for the hand on the cubic foot dial to make one
complete revolution, with all appliances off, except the furnace.
Take this information and locate it on the gas rate chart.
Observe the forty (40) seconds, locate and read across to the
one (1) cubic foot dial column. There we find the number 90,
which shows that ninety (90) cubic feet of gas will be consumed
in one (1) hour.
Let's assume the local gas utility has stated that the calorific
value of the gas is 1,025 BTU per cubic foot.
Multiplying the ninety (90) cubic feet by 1,025 BTU per cubic
foot gives us an input of 92,250 BTUH.
Checking the BTU input on the rating plate of the furnace
being tested.
EXAMPLE:
INPUT:
92,000 BTU/HR
OUTPUT CAP:
84,000
