SERVICING
69
Rev. 0
The following chart give the orifice drill size and high alti-
tude kit required for different elevations.
High altitude pressure switches and kits are listed on the
page 67 in the Pressure Switch Usage and Trip Point Chart.
Note: In Canada, gas furnaces are certified only to 4500
feet.
GUCA
GCCA
0 to
7,000 ft.
Nat. #43
Original Equipment
Factory Installed
(uses 10716003 orifices)
GUCA
GCCA
7,001 to
9,000 ft.
Nat. #44
HANG11
High Altitude Orifice Kit
(uses 10716004 orifices)
GUCA
GCCA
7,001 to
11,000 ft.
Nat. #45
HANG12
High Altitude Orifice Kit
(uses 10716005 orifices)
GUCA
GCCA
0 to
7,000 ft.
Propane
#55
LPTK09
Propane Conversion Kit
(uses 10716009 orifices)
GUCA
GCCA
7,001 to
11,000 ft.
Propane
#56
HALP10
High Altitude Orifice Kit
(uses 10716010 orifices)
ORIFICE SIZE AND HIGH ALTITUDE KIT CHART
S-19 CHECKING MINI IGNITER
A 120V ceramic/metallic composite mini-igniter is used for
ignition. Time to temperature for this igniter is within 5 sec-
onds. The normal operating temperature is approximately
1200° - 1450° C (2192° - 2642°F).
WARNING
Disconnect Electrical Power Supply:
1. Remove burner compartment door to gain access to
mini igniter.
2. Igniter cool - approximately 75°F.
3. Disconnect the mini igniter at the two pin connector that
connects it to the RD-2 and WH-33 wires from ignition
control.
4. Using an ohmmeter measure the resistance of the ig-
niter - should read between 50 to 300 ohms for igniter,
Amana part number 20165701, used in initial produc-
tion GUCA and GCCA models, and 30 to 175 ohms for
igniter, Amana part number 20165702, used in later pro-
duction GUCA and GCCA models.
5. Reconnect igniter.
WARNING
LINE VOLTAGE NOW PRESENT.
6. Place unit in heating cycle, measure current draw of
igniter during preheat cycle. Should read approximately
1 amp maximum. The steady state current at 120V is a
nominal of .7 plus or minus .3 amps.
7. After check and/or replacement of mini igniter, reinstall
burner compartment door and verify proper unit opera-
tion.
S-20
CHECKING WHITE-RODGERS 50A55-288
OR HEATCRAFT HSI-2 INTEGRATED IGNI-
TION CONTROL MODULES
Note: Failure to earth ground the furnace, reversing the
neutral and hot wire connection to the line (polarity), or a
high resistance connection in the neutral line may cause
the control to lockout due to failure to sense flame.
WARNING
To avoid the risk of electrical shock, wiring to the unit
must be properly polarized and grounded. Disconnect
power before performing service listed below.
The ground wire must run from the furnace all the way back
to the electrical panel. Proper grounding can be confirmed
by disconnecting the electrical power and measuring resis-
tance between the neutral (white) connection and the burner
closest to the flame sensor. Resistance should be less than
10 ohms.
The ignition control module is a combination electronic and
electromechanical device and is not field repairable. Com-
plete unit must be replaced.
The White-Rodgers 50A55 and Heatcraft HSI-2 ignition con-
trols, control all furnace operations including blower opera-
tion in air conditioning. Blower on time delays are controlled
by the ignition control and are nonadjustable, see
Circula-
tor Blower Speeds and Blower Heat Delay Timings sec-
tions located in the
Product Design section of this manual
for blower delay information.
WARNING
LINE VOLTAGE NOW PRESENT.
These tests must be completed within a given time frame
due to the operation of the ignition control. See
Sequence
of Operation section in the SYSTEM OPERATION section
of this manual for timing chart.
The ignition control is capable of diagnosing many furnace
failures to speed troubleshooting. A flashing red diagnostic
indicator light (White-Rodgers 50A55) or a flashing green
diagnostic indicator light (Heatcraft HSI-2) flashes a code
for any discovered failures. When the control is powered
up normally the light will flash once for about one second.
This can be used to test for 120 volts and 24 volts to the
control since both must be present for the light to flash. If
this step fails, check for 120 volts to the control and check
the transformer and its associated wiring. If this step is suc-
cessful give the control a call for heat and wait five (5) sec-
onds or until the furnace goes into lockout. If the control
detects a failure it will now be shown on the diagnostic indi-
cator light. Refer to the
Troubleshooting-Diagnostic Charts
in the
SYSTEM OPERATION section of this manual for
more detail on failure codes for each control.
