Goodman Amana AMH8 Service Instructions Manual page 45

MAINTENANCE
INDUCED DRAFT AND CIRCULATION BLOWERS
The bearings in the induced draft blower and circulator
blower motors are permanently lubricated by the manu-
facturer. No further lubrication is required. Check mo-
tor windings for accumulation of dust which may cause
overheating. Clean as necessary.
FLAME SENSOR (QUALIFIED SERVICER ONLY)
Under some conditions, the fuel or air supply can create
a nearly invisible coating on the flame sensor. This coat-
ing acts as an insulator, causing a drop in the flame
sensing signal. If this occurs, a qualified servicer must
carefully clean the flame sensor with steel wool. After
cleaning, the flame sensor output should be as listed on
the specification sheet.
BURNERS
HIGH VOLTAGE
E
LECTRICAL COMPONENTS ARE CONTAINED IN BOTH
T
COMPARTMENTS. O AVOID ELECTRICAL SHOCK, INJURY OR
DEATH, DO NOT REMOVE ANY INTERNAL COMPARTMENT COVERS
OR ATTEMPT ANY ADJUSTMENT.
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 down-
ward, 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
WARNING
C
ONTACT A QUALIFIED
TEST EQUIPMENT
Proper test equipment for accurate diagnosis is as es-
sential 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.
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.
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