Carrier Condensing Furnace Installation Manual
The Carrier Condensing Furnace is a high-efficiency gas furnace designed for residential heating applications. This multi-position furnace features condensing technology, variable-speed blower motor, electronic ignition, sealed combustion, PVC venting system, and advanced diagnostic controls. Below are key sections for safety, installation procedures, electrical connections, gas connections, venting, startup, and troubleshooting.
Features at a Glance
Key components: Condensing heat exchanger, variable-speed ECM blower, hot surface ignitor, pressure switches, flame sensor, integrated control board, PVC vent connections, combustion air intake.
| Feature | Description |
|---|
| Condensing heat exchanger | Stainless steel primary and secondary heat exchangers |
| Variable-speed ECM blower | Energy-efficient motor with multiple speed settings |
| Hot surface ignitor | Electronic ignition system (no standing pilot) |
| Pressure switches | Safety devices to verify proper venting |
| Flame sensor | Monitors burner flame presence |
| Integrated control board | Microprocessor-based control with diagnostic LEDs |
| PVC vent connections | 2-inch PVC for combustion air intake and flue gas exhaust |
| Multi-position capability | Upflow, downflow, horizontal left, horizontal right |
| AFUE rating | Up to 96% Annual Fuel Utilization Efficiency |
| Communication capability | Compatible with Carrier Infinity control systems |
Safety Precautions
Read all instructions before beginning installation. Follow local codes and manufacturer guidelines.
- Turn off electrical power and gas supply before installation.
- Wear appropriate PPE: safety glasses, gloves, and protective clothing.
- Ensure adequate combustion air and proper venting.
- Verify gas type matches furnace rating plate (natural gas or propane).
- Check for gas leaks using soap solution after connections.
WARNING! Failure to follow safety procedures may result in fire, explosion, carbon monoxide poisoning, or personal injury. Only qualified HVAC technicians should install this equipment.
Pre-Installation Requirements
Verify site conditions and gather necessary tools and materials.
- Location: Indoor installation only, protected from weather and moisture.
- Clearances: Maintain minimum clearances to combustibles as specified.
- Venting: Plan PVC vent routing with proper slope and termination.
- Gas supply: Verify adequate gas pressure and pipe sizing.
- Electrical: Dedicated 120V circuit required; check local codes.
- Drainage: Condensate drain line with proper trap and routing.
CAUTION! Furnace is heavy; use proper lifting techniques and equipment.
Specifications
- Input Capacity: 40,000 to 120,000 BTU/h (model dependent)
- AFUE Rating: Up to 96%
- Gas Type: Natural gas or propane (field convertible)
- Electrical: 120V AC, 60Hz, 15A circuit
- Blower Motor: Variable-speed ECM
- Venting: 2-inch PVC pipe (Category IV)
- Operating Temp: -30°F to 150°F ambient
- Sound Rating: Ultra-quiet operation
- Warranty: Limited lifetime heat exchanger, 10-year parts
Installation Procedures
Follow step-by-step installation sequence for proper operation.
- Position furnace: Set in desired orientation (upflow, downflow, horizontal)
- Install filter rack: Mount appropriate filter system
- Connect ductwork: Secure supply and return air connections
- Install vent system: Route PVC intake and exhaust pipes
- Connect gas line: Use black iron pipe with proper fittings
- Wire electrical: Connect line voltage and thermostat wiring
- Install drain line: Route condensate to suitable drain
- Verify installation: Check all connections and clearances
Electrical Connections
All electrical work must comply with NEC and local codes.
- Disconnect power at service panel before wiring.
- Connect line voltage: Black (hot), white (neutral), green (ground).
- Connect low voltage: R (24V hot), C (common), W (heat), G (fan).
- Install disconnect switch within sight of furnace.
- Verify proper grounding and polarity.
Tip: Use wire nuts and electrical tape for secure connections.
Gas Connections
Gas piping must be sized according to length and BTU input.
- Use black iron pipe or approved flexible connector.
- Install sediment trap before gas valve.
- Apply pipe thread compound to male threads only.
- Install manual shutoff valve within 6 feet of furnace.
- Pressure test: Check for leaks with soap solution.
- Verify gas pressure: Natural gas 3.5" WC, propane 10" WC.
WARNING! Gas leaks can cause explosion or fire. Test thoroughly.
Venting System
Category IV sealed combustion system requires proper PVC venting.
- Use only PVC, CPVC, or ABS pipe approved for furnace venting.
- Maintain 1/4" per foot slope back to furnace.
- Keep intake and exhaust pipes within specified maximum length.
- Terminate vents according to clearance requirements.
- Secure joints with PVC cement and primer.
- Install bird screens on termination fittings.
CAUTION! Improper venting can cause carbon monoxide hazards.
Startup & Commissioning
Follow systematic startup procedure for safe operation.
- Verify all connections are complete and secure.
- Restore electrical power and gas supply.
- Set thermostat to call for heat.
- Observe ignition sequence: inducer, pressure switch, ignitor, gas valve.
- Check flame appearance: Steady blue flame with yellow tips.
- Measure temperature rise: Adjust blower speed if necessary.
- Verify proper vent operation and condensate drainage.
- Complete installation checklist and leave with homeowner.
Maintenance
Regular maintenance ensures optimal performance and longevity.
- Monthly: Check and replace air filter as needed
- Annual: Professional inspection and cleaning
- Clean burners and heat exchanger annually
- Check condensate drain system monthly
- Verify vent system clear of obstructions
- Test safety controls and operation
CAUTION! Turn off power and gas before performing any maintenance.
Troubleshooting
| Symptom | Possible Cause | Corrective Action |
|---|
| Furnace won't start | Power, thermostat, door switch | Check circuit breaker, thermostat settings, door switch engagement |
| No heat | Gas supply, ignitor, flame sensor | Verify gas valve open, check ignitor continuity, clean flame sensor |
| Short cycling | Filter, limit switch, venting | Replace dirty filter, check high limit, verify proper venting |
| Blower won't run | Motor, capacitor, control board | Check motor voltage, test capacitor, inspect control board |
| Condensate backup | Drain line clogged | Clear drain line, check trap, ensure proper slope |
| Error codes flashing | Various faults | Refer to diagnostic chart in service manual |
Reset: Power cycle furnace to clear temporary faults.
Service: Contact authorized Carrier dealer for technical support.
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