368262-UIM-B-1008
ACCESSORY CONNECTIONS
The furnace control will allow
ELECTRONIC AIR CLEANER CONNECTION
Two 1/4” (0.64 cm) spade terminals (EAC and NEUTRAL) for electronic air cleaner connections are located on the control board. The terminals provide 115 VAC (1.0 amp maximum) during circulating blower opera- tion.
HUMIDIFIER CONNECTION
Two 1/4” (0.64 cm) spade terminals (HUM and NEUTRAL) for humidi- fier connections are located on the control board. The terminals provide 115 VAC (1.0 amp maximum) during heating system operation.
A mounting hole is provided on the control panel next to the furnace control board for mounting a humidifier transformer if required.
HUMIDISTAT CONNECTION
For better humidity control during cooling operation, an external humi- distat may be used. When using a external humidistat, put the HUMI- DISTAT jumper in the “YES” position. Connect the low voltage wiring as shown in Figures
ZONING OPERATION
This furnace may be used in zoning systems, using a separate after- market zoning control. For use in zoned systems, put the ZONE CON- TROL jumper on the furnace control board in the “YES” position.
If the Zone jumper is put in the “Yes” position, the heating load logic switches to a special algorithm for
1.This algorithm operates at the “low demand” firing rate for 10 min- utes and then ramps to high fire within 20 minutes (30 minutes maximum to get to 100% firing rate).
2.The special zoning algorithm does not have the Run 2 function, so the burners will stop firing as soon as there is no call for heating.
HEAT PUMP OPERATION
This furnace may be used in conjunction with a heat pump in dual fuel applications. For heat pump applications, put the HEAT PUMP jumper on the furnace control board in the “YES” position. Connect the low volt- age wiring as shown in Figures
If the Heat Pump jumper is in the “Yes” position, it indicates that there is a heat pump present and the furnace is used as a secondary heat source. In addition, the “Yes” Heat Pump jumper allows the system to read the presence of the “O” terminal signal. In heat pump operation, the following special algorithm logic applies:
1.Supplemental Heating - When both a “W” signal and a “Y1” signal are present, the modulating firing rate will operate as normal, except there will be no Run 2 function, so the burners will stop fir- ing as soon as the “W” signal is removed.
2.Defrost Cycle - When both a “W” signal and a “Y2” signal are present, the modulating firing rate will operate at a constant 80% firing rate and there will be no Run 2 function, so the burners will stop firing as soon as the “W” signal is removed..
3.Hot Heat Pump - The “hot” heat pump feature will work when the control is wired to a
4.Hot Heat Pump - The “hot” heat pump feature will not work when the control is wired to a
TWINNING
These furnaces are not to be twinned. If more than one furnace is needed in an application, each furnace must have its own complete duct system and its own wall thermostat.
SECTION VI: VENT SYSTEM
VENT CONNECTIONS
Figure 25 shows the furnace as it is shipped from the factory. To convert to a horizontal or downflow position, remove the four screws that secure the inducer assembly and rotate 90° being careful not to damage the gasket. Reinstall screws. Remove cap from appropriate vent outlet location on the cabinet cut insulation in cabinet to same size as the hole provided and reinstall cap in the hole in the top panel.
In downflow applications, do not block the combustion air inlet. The furnace must be installed on a coil cabinet or subbase to allow com- bustionair to enter the burner compartment.
COMBUSTION AIR INDUCER
90° | Mounting Screw | 90° |
| (Remove) |
|
Pressure Switch
Tube Routing 
Flue Transition
(Do Not Remove)
Pressure
Switch
Mounting Screw (Remove)
FIGURE 25: Combustion Air Inducer
CATEGORY 1 - 450 F. MAX. VENT TEMP.
The venting system must be installed in accordance with Section 5.3, Air for Combustion and Ventilation, of the National Fuel Gas Code Z223.1/NFPA 54 (latest edition), or Sections 7.2, 7.3 or 7.4 of CSA B149.1, National Gas and Propane Codes (latest edition) or applicable provisions of the local building code and these instructions.
The furnace shall be connected to a type B vent connector, and shall be connected to a type B vent only. The furnace shall not be connected to a chimney flue serving a separate appliance designed to burn solid fuel.
It is recommended that the appliance is installed in a location where the space temperature is 32 °F (0°C) or higher. If the appliance is installed in a location where the ambient temperature is below 32 °F (0°C), the combustion byproducts could condense causing damage to the appli- ance heat exchanger.
This appliance may be common vented with another gas appliance for residential installations as allowed by the codes and standards listed in these instructions.
VENTING
Category I venting consists of vertically venting one or more appliances in
VENTING INTO AN EXISTING CHIMNEY
This furnace may not be vented directly into an unlined or clay
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