Amana GULA, User'S Information Manual

Page: 11 / 18

11
Safety Circuits
A number of safety circuits are employed to ensure safe and proper furnace operation. These circuits serve to control
any potential safety hazards and, as inputs in the monitoring and diagnosis of abnormal function. These circuits are
continuously monitored by the integrated control module.
Integrated Control Module
The integrated control module is an electronic device
which regulates all furnace operations. Responding to the
thermostat, the module initiates and controls normal
furnace operation, and monitors and addresses all safety
circuits. If a potential safety concern is detected, the
module will take the necessary precautions and provide
diagnostic information through an LED displayed on the
module.
Primary Limit
The primary limit control is located on the partition panel
and monitors heat exchanger compartment tempera-
tures. It is a normally closed (electrically), automatic re-
set, temperature activated sensor. This limit guards
against overheating as a result of insufficient conditioned
air passing over the heat exchanger.
Auxiliary Limit
The auxiliary limit control is located on or near the blower
deck and monitors heat exchanger compartment tem-
peratures. It is a normally closed (electrically), manual
reset, temperature activated sensor. This limit guards
against overheating as a result of insufficient conditioned
air passing over the heat exchanger.
Rollout Limit
The rollout limit is a normally-closed (electrically),
manual-reset, temperature-activated sensor. It is
mounted on the burner/manifold assembly and monitors
the burner flame. If there is an improper draw of burner
flames into the heat exchanger, the rollout limit will detect
it and shutdown gas flowing to the burners.
Pressure Switches
The pressure switches are normally-open (closed during
operation), single-pole single-throw, negative air pressure
activated switches. They monitor the airflow (combustion
air and flue products) through the heat exchanger via
pressure taps located on the induced draft blower and the
coil front cover. These switches guard against insufficient
airflow (combustion air and flue products) through the heat
exchanger and blocked condensate drain conditions.
Flame Sensor
The flame sensor is a probe mounted to the burner/mani-
fold assembly which uses the principle of flame rectifica-
tion to determine the presence or absence of flame.
PRIMARY LIMIT ROLLOUT
LIMIT(S)
AUXILIARY LIMIT
(UNDERSIDE OF BLOWER DECK)
CIRCULATOR
BLOWER
BLOWER
DECK
PRESSURE
SWITCH
PRESSURE
SWITCH
FLAME SENSOR
Safety Circuits
Resetting From Lockout
Furnace lockout is characterized by a non-functioning
furnace (circulator blower may be running continuously)
providing a one flash diagnostic LED code. Lockout
results when a furnace is unable to achieve ignition after
three attempts, or when it has lost flame five times
during a single call for heat. If the furnace is in “lockout”,
it may be reset by any of the following methods:
1. One hour automatic reset. Control will automatically
reset itself and attempt to resume normal operations
following a one hour lockout period.
2. Power interruption. Interrupt 115 volt power to the
furnace for between 0 and 20 seconds.
3. Thermostat cycle. Interrupt thermostat signal to the
furnace for between 0 and 20 seconds.
If the condition which originally caused the lockout still
exists, the control will return to lockout. If your furnace
frequently locks out, a problem exists which must be
corrected. Contact a qualified servicer.