Installation: National Comfort Products Comfort Pack Series Electric Heat Kit Instruction Guide

Overview

The Comfort Pack Series Electric Heat Kit is a field-installed electric resistance heating accessory for compatible National Comfort Products Comfort Pack units and multi-family air handlers. It adds supplemental or primary electric heat to a self-contained through-the-wall heating and cooling system.

Designed for qualified HVAC professionals, the kit uses heater banks, circuit-breaker protection, control wiring, and a properly selected blower-speed setting to deliver heated air through the existing air-handling system. Read the complete installation documentation before beginning work, and keep the guide with the equipment for future reference.

Specifications

• Heat kit models: CPEHK-03-A, CPEHK-05-A, CPEHK-07-A, CPEHK-10-A, and CPEHK-15-A.
• Nominal heating sizes: 3, 5, 7, 10, and 15 kW.
• Heating capacity at 230 V: 10,900, 16,000, 22,400, 32,000, and 47,800 Btu/h, respectively.
• Heating capacity at 208 V: 8,900, 13,100, 18,300, 26,000, and 39,200 Btu/h, respectively.
• Electrical systems: 208 or 230 V, single phase, 60 Hz applications.
• Maximum outlet-air temperature: 200°F.
• Maximum external static pressure: 0.5 in. water column.
• Minimum clearance to combustible surfaces: 0 inches, subject to the complete unit installation requirements and applicable codes.
• Compatible Comfort Pack examples: CPE41200U*, CPE41800U*, CPE41240U*, and CPE413000T* models listed in the installation guide.
• Compatible air handlers: NAH424MF*-L*, NAH424MF*-R*, NAH430MF*-L*, and NAH430MF*-R* families listed in the guide.
• Refrigerant application: Use with compatible outdoor equipment using R-410A refrigerant as specified on the equipment data label.
• Installation location: Indoor installation only.
• Conductors: Copper conductors are required.

Detailed Description

The Comfort Pack Series Electric Heat Kit contains one or more electric heater banks that warm air as it passes through the furnace or air-handler section. Depending on the selected model, the kit supplies from 3 to 15 kW of resistance heat.

Major components include the heater banks, circuit breaker or breakers, power harness, control harness, heater relays, high-limit protection, fusible links, and mounting hardware. The blower moves air across the energized heater banks, while the control system manages the heating call and blower operation.

The kit is installed inside the existing equipment cabinet rather than as a separate outdoor heating appliance. The breaker assembly provides branch-circuit protection, while the unit’s high-limit and fusible-link components help protect against excessive heater temperatures. The equipment data label identifies the installed heat-kit model, heating rating, minimum circuit ampacity, and maximum fuse or breaker size.

Safety

• Installation and service must be performed by personnel familiar with HVAC equipment and electrical systems.
• Disconnect all electrical power before installing or servicing the heater kit. More than one disconnect may supply the equipment.
• Install strain relief and conductor protection where supply wiring enters the cabinet.
• Use copper conductors only.
• Follow the National Electrical Code and all applicable national, state, and local requirements.
• After wiring, verify that every breaker terminal screw is properly tightened. Loose connections can cause malfunction, fire, severe injury, or property damage.
• If the equipment is installed in an enclosed space containing a fuel-burning or other carbon-monoxide-producing appliance, provide suitable ventilation.
• Do not operate the equipment beyond the voltage, airflow, static-pressure, or temperature limits shown on the unit data and installation documentation.
• Do not discard this guide. Store it in a safe location with the equipment.

Setup and Installation

Record the heat-kit model number, equipment serial number, and installation date before starting. Confirm that the selected kit is approved for the specific Comfort Pack or air-handler model and that the electrical service can support the listed minimum circuit ampacity and maximum overcurrent protection.

Comfort Pack installation

1. Remove the upper access panel from the cabinet.
2. Remove the heater cover plate and retain the two screws for reuse.
3. Slide the heater banks into the opening and secure them with four screws. Use additional screws from the accessory kit if required.
4. Install the circuit breaker or breakers on the bracket at the front of the furnace section.
5. Disconnect and remove the cabinet power harness from the adapter plug located at the horizontal air divider.
6. Connect the heat-kit power and control harnesses to their matching connectors.
7. Connect the external power conductors to the free side of the heat-kit circuit breaker or breakers according to the unit wiring diagram.
8. Reinstall the upper access panels and fit the matching breaker patch plate from the accessory kit.
9. Remove the filter access panel.
10. Set the correct blower-speed tap, including the orange wire where specified, on the blower-speed control board. Use the airflow tables for the installed unit and heat-kit size.
11. Reinstall the filter access panel.
12. Check the installed heat-kit model on the unit data label.
13. Attach the supplied wiring-diagram label in the designated area of the cabinet wiring diagram.

Multi-family air-handler installation

1. Remove the required access panels from the air-handler cabinet.
2. Disconnect and remove the air handler’s existing power-wire harness.
3. Remove the heater cover plate and retain the four screws.
4. Insert the heater banks into the opening and fasten them with four screws.
5. Move the control board from the front board bracket to the bracket supplied with the heat kit.
6. Mount the circuit breaker or breakers on the front board bracket.
7. Connect the correct blower-speed tap wires to the cooling and heater fan-output terminals on the control board. Use the air-handler airflow tables to select the proper settings.
8. If cooling and heating require the same motor speed, install the required terminal splitter and jumper wire.
9. Connect the heat-kit power and control harnesses to the corresponding air-handler connectors.
10. Connect external power wiring to the free side of the heat-kit breaker or breakers.
11. Install the supplied wiring-diagram label in the designated area of the air-handler wiring diagram.
12. Reinstall the upper access panels and install the appropriate breaker patch plate.
13. Check the installed heat-kit model on the air-handler data label.

Electrical selection guide

Use the unit-specific data table rather than selecting protection from the heater kilowatt rating alone. The following values summarize the listed Comfort Pack ratings; always verify the exact equipment model before installation.

• CPEHK-03-A: 3 kW; 10,900 Btu/h at 230 V or 8,900 Btu/h at 208 V; maximum protection is generally 25 A, with model-dependent variations.
• CPEHK-05-A: 5 kW; 16,000 Btu/h at 230 V or 13,100 Btu/h at 208 V; maximum protection ranges from 30 to 35 A depending on the equipment model.
• CPEHK-07-A: 7 kW; 22,400 Btu/h at 230 V or 18,300 Btu/h at 208 V; maximum protection ranges from 40 to 45 A depending on the equipment model.
• CPEHK-10-A: 10 kW; 32,000 Btu/h at 230 V or 26,000 Btu/h at 208 V; maximum protection is typically 50 or 60 A depending on the equipment model.
• CPEHK-15-A: 15 kW; 47,800 Btu/h at 230 V or 39,200 Btu/h at 208 V; some air-handler applications use split circuit ratings, such as 60/30 A or 50/30 A.

The heater specifications include total operating amps, minimum circuit ampacity, and maximum overcurrent protection for both 208 V and 230 V. The correct breaker or fuse size must be taken from the data label and the table for the exact unit and heat-kit combination.

Wiring and Controls

Follow the complete wiring diagram supplied with the equipment. The diagram identifies the control board, transformer, terminal board, blower motor, heater relays, heaters, high limits, fusible links, breakers, thermostat terminals, and line-voltage connections.

Common diagram abbreviations include CB for control board, EBM for evaporator blower motor, XFMER for transformer, BR for breaker, FL for fusible link, HL for high limit, HR for heat relay, and HTR for heater. These labels help match the field wiring to the printed equipment diagram.

The blower-speed control must be set for the installed heating capacity and unit airflow requirement. An incorrect speed can reduce comfort, cause excessive temperature rise, or activate safety limits. Complete airflow settings must be taken from the applicable Comfort Pack or air-handler installation manual.

Documentation and Final Checks

• Confirm that all heater-bank mounting screws are installed and secure.
• Verify that the power and control harnesses are connected to the correct mating connectors.
• Check breaker terminal tightness after wiring is complete.
• Confirm that supply conductors have suitable strain relief and protection at the cabinet entrance.
• Verify the selected blower-speed tap against the unit airflow table.
• Install the breaker patch plate and replace every access panel.
• Mark the installed heat-kit model on the equipment data label.
• Apply the supplied wiring-diagram label in the specified location.
• Before operation, inspect the installation for loose wires, exposed conductors, damaged insulation, or obstructions to airflow.

Pros & Cons

• Pros: Available in five heating capacities, integrates into compatible Comfort Pack and multi-family air-handler cabinets, includes breaker protection, and uses existing blower and control systems.
• Pros: The installation guide provides model-specific heating capacities, ampacity values, breaker limits, wiring references, and blower-speed instructions.
• Cons: Installation requires qualified electrical and HVAC work, careful breaker selection, cabinet disassembly, and verification of airflow settings.
• Cons: Compatibility and electrical ratings vary by equipment model, so the heat-kit size cannot be selected safely from kilowatts alone.