Keeprite DC90 Furnace Manual

The Keeprite DC90 is a high-efficiency gas furnace with 90% AFUE rating, featuring two-stage heating operation, variable-speed blower motor, durable heat exchanger, electronic ignition system, diagnostic LED indicator, and compatibility with standard thermostat controls. Designed for residential use with natural gas or propane capability. Below are key sections for safety, features, installation, operation, maintenance, and troubleshooting.

1. Features at a Glance 2. Installation Requirements 3. First-Time Setup 4. Technical Specifications 5. Controls and Operation 6. Venting and Combustion Air 7. Maintenance Procedures 8. Safety Features 9. Care & Cleaning 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: Two-stage gas valve, variable-speed ECM blower motor, aluminized steel heat exchanger, hot surface ignitor, pressure switches, flame sensor, and diagnostic control board.

Feature	Description
Two-stage operation	Provides high and low fire settings for improved comfort and efficiency
Variable-speed blower	ECM motor for quiet operation and better air circulation
Diagnostic LED	Flashing light indicates system status and error codes
Dual-fuel capability	Compatible with heat pump systems
Sidewall venting	PVC pipe venting system
Multi-speed blower	Adjustable airflow for different duct systems
Electronic ignition	Hot surface ignitor for reliable lighting
Pressure switches	Safety devices to ensure proper venting
Flame sensor	Detects burner flame for safety shutdown
Control board	Microprocessor for system operation and diagnostics

Installation Requirements

Professional installation required. Verify local codes and obtain permits.

Location: Install in dry, clean area with adequate clearance for service.
Venting: Use approved PVC pipe for intake and exhaust; maintain proper slope.
Gas connection: Use black iron pipe with drip leg; pressure test for leaks.
Electrical: 120V AC power supply with proper grounding.
Ductwork: Ensure proper sizing and sealing for optimal performance.

WARNING! Gas appliances can be dangerous if improperly installed. Use qualified HVAC technician.

First-Time Setup

Initial startup must be performed by qualified technician.

Verify installation: Check all connections, clearances, and venting.
Gas pressure: Adjust manifold pressure per specifications.
Blower speed: Set appropriate CFM for heating operation.
Thermostat: Connect compatible two-stage thermostat.
Test operation: Run through complete heating cycle.

CAUTION! Never attempt gas adjustments without proper training and equipment.

Technical Specifications

AFUE Rating: 90%
Heating Capacity: 40,000 - 120,000 BTU/h (multiple models)
Stages: Two-stage heating operation
Blower Type: Variable-speed ECM
Fuel Type: Natural gas or propane
Electrical: 120V, 60Hz, 15A circuit
Venting: 2" PVC pipe (intake and exhaust)
Sound Level: < 65 dBA
Dimensions: Varies by model (typically 21"W x 21"D x 45"H)
Warranty: 20-year heat exchanger, 5-year parts

Controls and Operation

Integrated control board manages all furnace functions. Access door switch must be engaged for operation.

Thermostat: Compatible with most 24V thermostats; two-stage operation recommended.

Operation sequence: Call for heat → Inducer motor on → Pressure switch verification → Hot surface ignitor on → Gas valve opens → Flame sensor verification → Blower motor on.

Diagnostic LED: Green for normal operation; flashing codes indicate specific issues.

Venting and Combustion Air

Direct vent system using PVC pipe. Follow local codes for vent termination.

Vent pipe: Use only approved PVC material; maintain 1/4" per foot slope.
Termination: Keep clear of windows, doors, and air intakes.
Combustion air: Provide adequate fresh air for proper combustion.
Clearances: Maintain specified distances from combustible materials.

Tip: Regular inspection of vent pipes for blockage or damage is essential.

Maintenance Procedures

Annual maintenance by qualified technician recommended.

Air filter: Replace every 1-3 months depending on usage.
Burners: Inspect and clean annually for proper flame pattern.
Heat exchanger: Visual inspection for cracks or corrosion.
Blower assembly: Clean wheel and motor annually.
Vent system: Check for obstructions and proper slope.
Drain system: Clear condensate trap and drain lines.
Electrical: Check all connections and component operation.
Gas pressure: Verify proper manifold and inlet pressures.

WARNING! Turn off power and gas supply before performing any maintenance.

Safety Features

Multiple safety systems: Flame rollout switches, high limit switch, pressure switches, flame sensor, door safety switch.

Care & Cleaning

Keep area around furnace clean and clear. Regular filter changes essential for efficiency.

CAUTION! Never store combustible materials near furnace. Keep vents clear.

Regulatory Information

UL listed and ANSI certified. Complies with applicable safety standards. Natural gas models certified for use in USA and Canada. For technical support, contact Keeprite customer service at 1-800-265-1849 or visit www.keeprite.com.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Furnace won't start	Power, thermostat, door switch	Check circuit breaker, thermostat setting, ensure door closed properly.
No heat	Gas supply, ignitor, flame sensor	Verify gas valve on, check for dirty flame sensor, inspect hot surface ignitor.
Short cycling	Dirty filter, high limit	Replace air filter, check for restricted airflow, verify high limit operation.
Blower won't stop	Thermostat, control board	Check thermostat fan setting, inspect control board relay.
Error code flashing	Various system faults	Refer to diagnostic chart in service manual for specific code meaning.

Reset: Turn power off for 30 seconds to reset control board.

Service: 1-800-265-1849; www.keeprite.com