High Altitude Application (Usa); Checking For Delayed Ignition; Checking Integrated Ignition Control Boards - Goodman Amana AMH8 Service Instructions Manual

SERVICING
Induced Draft Blower
Pressure Switch
1/4" Tee
ID Blower Pressure Switch
Negative Pressure Measurement
(80% Upflow Single-Stage Furnace Shown,
Counterflow Similar)
S-311 HIGH ALTITUDE APPLICATION (USA)
Check your furnace rated altitude on the furnace rating
plate. Do not attempt to increase the firing rate by
changing orifices or increasing the manifold pressure
below rated altitude. This can causepoor combustion
and equipment failure. High altitude installations above
rated altitude may require both a pressure switch and
an orifice change. These changes are necessary to com-
pensate for the natural reduction in the density of both
the gasfuel and the combustion air at higher altitude.
For installations above rated altitude, please refer to
your distributor for required kit(s). Contact the distribu-
tor for a tabular listing of appropriate manufacturer's
kits for propane gas and/or high altitude installations.
The indicated kits must be used to insure safe and proper
furnace operation. All conversions must be performed
by a qualified installer, or service agency.
In some areas the gas supplier may artificially derate
the gas in an effort to compensate for the effects of
altitude. If the gas is artificially derated the appropri-
ate orfice size must be determined based on the BTU/
ft content of the derated gas and the altitude. Refer to
3
the National Fuel Gas Code, NFPA 54/ANSI Z223.1, and
information provided by the gas supplier to determine
the proper orifice size.
Pressure Switch
Hose
Inclined Manometer
Hose to Induced
Draft Blower Tap
S-312 CHECKING FOR DELAYED IGNITION
Delayed ignition is a delay in lighting a combustible
mixture of gas and air which has accumulated in the
combustion chamber.
Furnace design makes this extremely unlikely unless
safety controls have been by-passed or tampered with.
Never by-pass or alter furnace controls.
If delayed ignition should occur, the following should
be checked:
1. Improper gas pressure - adjust to proper pressure
(See S-307 CHECKING GAS PRESSURE).
2. Improper burner positioning - burners should be in
locating slots, level front to rear and left to right.
3. Carry over (lighter tube or cross lighter) obstructed
- clean.
4. Main burner orifice(s) deformed, or out of align-
ment to burner - replace.
S-313 CHECKING INTEGRATED IGNITION CON-
TROL BOARDS
NOTE: Failure to earth ground the furnace, reversing
the neutral and hot wire connection to the line (polar-
ity), or a high resistance connection in the neutral line
may cause the control to lockout due to failure to sense
flame.
WARNING
T
O AVOID THE RISK OF ELECTRICAL SHOCK, WIRING TO THE UNIT
MUST BE PROPERLY POLARIZED AND GROUNDED.
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 resistance between the neutral (white) con-
nection and the burner closest to the flame sensor.
Resistance should be less than 2 ohms.
The ignition control is a combination electronic and
electromechanical device and is not field repairable.
Complete unit must be replaced.
WARNING
L
INE VOLTAGE NOW PRESENT
These tests must be completed within a given time
frame due to the operation of the ignition control.
The ignition control is capable of diagnosing many fur-
nace failures to help in troubleshooting. The trial for
ignition period is 4 seconds.
D
ISCONNECT POWER
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