If, during the inspection of your furnace, you find any of the following conditions:
•Excessive amounts of dust and lint on components.
•Damaged or deteriorated components or surfaces.
•Leaks or blockage in the vent pipe passages.
•Water on any surface inside or outside of the furnace.
Do not operate the furnace, call a certified dealer / servicing contractor to check and / or clean your furnace, or for more information if you have questions about the operation of your furnace.
If all components appear to be in good operating condition, replace the front panels. Turn ON the gas and electrical power supplies to the fur- nace, and set thermostat to the desired temperature.
Motor Lubrication
The motors in these furnaces are permanently lubricated, and do not require periodic oiling.
TABLE 1: Filter Sizes
Input / Output | CFM | Cabinet | Top Return |
BTU/H (kW) | (m3/min) | Size | Filter in(cm) |
40/37 (11.72/10.84) | 1200 (34) | A | (2) 14 x 20 (36 x 51) |
60/55 (17.57/16.10) | 1200 (34) | B | (2) 14 x 20 (36 x 51) |
80/75 (23.42/21.96) | 1200 (34) | B | (2) 14 x 20 (36 x 51) |
80/75 (23.42/21.96) | 1600 (45) | C | (2) 14 x 20 (36 x 51) |
100/95 (29.28/27.82) | 1600 (45) | C | (2) 14 x 20 (36 x 51) |
100/95 (29.28/27.82) | 2000 (57) | C | (2) 14 x 20 (36 x 51) |
120/112 (35.14/32.80) | 2000 (57) | D | (2) 14 x 20 (36 x 51) |
SECTION II: SERVICE AND MAINTENANCE MANUAL
SAFETY SECTION
The following safety rules must be followed when servicing the furnace.
ELECTRIC SHOCK, FIRE OR EXPLOSION HAZARD Failure to follow safety warnings exactly could result in dangerous operation, serious injury, death or property damage.
Improper servicing could result in dangerous operation, serious injury, and death or property damage.
•Before servicing, disconnect all electrical power to the fur- nace.
•When servicing controls, label all wires prior to discon- necting. Reconnect wires correctly.
•Verify proper operation after servicing.
FURNACE MAINTENANCE SECTION
The furnace should be cleaned and adjusted by a certified dealer or qualified service contractor once a year or before the start of every heating season. The following items must be cleaned and serviced or replaced if there are signs of deterioration.
1.The vent terminal screen (if applicable).
2.The furnace vent and combustion air intake passageways. Should it be necessary to service the vent/air intake system, the manufac- turer recommends this service be conducted by a qualified service agency. The operation of this appliance requires the reassembly and resealing of the vent/air intake system.
3.The furnace burners, ignitor and flame sensor.
4.The condensate collection and disposal system. If any disassem- bly of components containing flue or vent gases is required, a qualified service agency must perform the service.
SEQUENCE OF OPERATION
The following describes the sequence of operation of the furnace. Refer to Figure 1 for component location.
Continuous Blower
Cooling/heating thermostats have a fan switch that has an ON and AUTO position. In the ON position the thermostat circuit is completed between terminals R and G. The motor will operate on the speed tap selected on the Continuous Fan Speed Jumper on the control board (HI COOL, LO COOL, or HEAT pins).
Intermittent Blower - Cooling
Cooling/heating thermostats have a fan switch that has an ON and AUTO position. In the AUTO position the thermostat circuit is completed between terminals R and G when there is a call for cooling. The motor will operate on the speed tap wire that is connected to the HI COOL ter- minal on the control board. When used with
Heating Cycle
When the thermostat switch is set on HEAT and the fan is set on AUTO, and there is a call for heat, a circuit is completed between terminals R and W of the thermostat. When the proper amount of combustion air is being provided, the pressure switch will close, the ignition control pro- vides a
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| YELLOW - MED. LOW SPEED |
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| BLACK - HIGH SPEED |
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| BLUE |
PARK PARK | LO COOL | HICOOL | HEAT | EAC | L1 | XFMR | HUM | NEUTRALS |
CONTINUOUS
FAN SPEED
JUMPER
FAN OFF
ADJUSTMENT
JUMPER
FIGURE 8: Typical Heat/Cool Speed Tap Connections
If the flame is not detected within 2 seconds of the gas valve opening, the gas valve is shut off and a retry operation begins. If the flame is lost for 2 seconds during the
Unitary Products Group | 5 |