Coleman furnaces use LED light patterns to communicate error codes. These codes help diagnose issues and guide troubleshooting efforts.
Common Coleman Furnace Error Codes List
When troubleshooting a Coleman furnace, it’s essential to understand the error codes that the control board displays. These codes can help identify the specific issue affecting the furnace’s performance. Here are some of the most common Coleman furnace error codes and their meanings:
LED Status Codes
| LED Status | Meaning |
|---|---|
| LED off | No power. Check the power supply to the furnace. |
| Slow green flashing | Normal operation, no call for heat. Check the thermostat settings. |
| Slow amber flashing | Normal operation, calling for heat. Proceed with further diagnostics if the furnace isn’t heating properly. |
| 4 amber flashes | Improper thermostat wiring or a faulty thermostat. Book a professional repair. |
| LED red, not flashing | Faulty control board. Book a professional repair. |
| Rapid red flashing | Twinning error or incorrect 24V phasing. Possible wiring problem. Book a professional repair. |
Red Flash Codes
| Red Flashes | Meaning |
|---|---|
| 1 red flash | Flame sensed with gas valve closed. Faulty gas valve or control board. Book a professional repair or perform a gas valve diagnostic. |
| 2 red flashes | Pressure switch stuck in closed position. Faulty pressure switch or control board. Book a professional repair. |
| 3 red flashes | Pressure switch stuck in open position. Proceed with further diagnostics. |
| 4 red flashes | Limit switch open. Proceed with further diagnostics. |
| 5 red flashes | Roll out switch open. Blocked exhaust or secondary heat exchanger, or faulty inducer motor. Book a professional repair or perform a roll out switch diagnostic. |
| 6-8 red flashes | Locked out on various errors. Proceed with further diagnostics. |
| 9 red flashes | Grounding or polarity issue. Possible faulty control board. Book a professional repair. |
| 10 red flashes | Gas continues to flow with gas valve closed. Possible faulty gas valve. Book a professional repair or perform a gas valve diagnostic. |
| 11 red flashes | Limit switch open for more than five minutes. Possible faulty blower motor. Book a professional repair or perform a blower motor diagnostic. |
| 12 red flashes | Open igniter circuit. Faulty wiring or igniter. Book a professional repair or perform an igniter diagnostic. |
When encountering an error code, it’s crucial to observe the flashing LED sequence or display code carefully and match it with the corresponding code in the list above. Depending on the issue, homeowners may need to proceed with further diagnostics or book a professional repair to resolve the problem and restore the furnace’s proper functioning.
Pre-Troubleshooting Checklist
Before diagnosing Coleman furnace error codes, it’s essential to prepare properly and gather the necessary tools. This ensures a safe and efficient troubleshooting process.
Safety First: Preparing for Diagnosis
Turn off the furnace’s power supply at the circuit breaker or fuse box. Allow the unit to cool down completely before starting any work. Put on protective gear, including safety glasses and gloves.
Ensure proper ventilation in the work area. Open windows or doors if necessary. Clear the space around the furnace, removing any flammable materials or objects that might obstruct access.
Familiarize yourself with the furnace’s manual and layout. Locate the main gas shut-off valve and know how to use it in case of emergencies.
Tools and Equipment Needed
Gather these essential tools for troubleshooting:
- Multimeter for electrical testing
- Screwdrivers (flathead and Phillips)
- Flashlight for improved visibility
- Wire strippers and pliers
- Digital thermometer
- Vacuum cleaner with attachments
Keep a notepad and pen handy to record observations and error codes. A camera or smartphone can be useful for documenting component positions before disassembly.
Consider having replacement parts on hand, such as air filters, igniters, or flame sensors. These common components often require replacement during troubleshooting.
Step-by-Step Troubleshooting
Coleman furnace troubleshooting involves systematically checking key components to identify and resolve issues. Following a structured approach helps pinpoint problems efficiently and restore proper furnace operation.
Assessing Thermostat Issues
Check the thermostat settings and power source. Ensure it’s set to “Heat” mode and the temperature is above the current room temperature. Replace batteries if needed. Verify proper wiring connections between the thermostat and furnace.
Clean dust and debris from inside the thermostat. Test voltage across thermostat terminals to confirm proper signals are sent to the furnace. If issues persist, consider replacing the thermostat.
Inspecting Air Filters and Ductwork
Examine the air filter for dirt and debris buildup. Replace disposable filters or clean reusable ones monthly. A clogged filter restricts airflow, reducing efficiency and potentially causing overheating.
Inspect ductwork for leaks, gaps, or obstructions. Seal any leaks with metal tape or mastic sealant. Remove debris from vents and registers. Ensure dampers are open and properly positioned.
Consider professional duct cleaning if excessive dust or mold is present. Proper airflow is crucial for efficient furnace operation.
Checking the Ignition System
For older furnaces, inspect the pilot light. If it’s out, relight following manufacturer instructions. Check the thermocouple for proper positioning and cleanliness. Replace if faulty.
In newer furnaces with electronic ignition, listen for clicking sounds during startup. No clicking may indicate a faulty ignitor. Test the ignitor’s resistance with a multimeter. Replace if readings are outside the specified range.
Inspect wiring connections to the ignition system. Tighten loose connections and replace damaged wires.
Evaluating the Flame Sensor and Burners
Locate the flame sensor rod. Gently clean it with fine-grit sandpaper to remove any buildup. Ensure proper positioning near the burner flame.
Inspect burners for rust, debris, or misalignment. Clean with a wire brush and vacuum. Check for even flame distribution across all burners. Adjust if necessary.
Verify gas pressure at the burner manifold. Low pressure can cause weak flames and poor heating performance.
Examining the Blower Motor and Capacitors
Listen for unusual noises from the blower motor. Lubricate if bearings are dry. Check for loose mounting bolts and tighten if needed.
Test blower motor capacitors with a multimeter. Replace if readings are outside the specified range. Inspect wiring connections to the motor and control board.
Verify proper voltage to the blower motor. If the motor fails to start or runs erratically, replacement may be necessary.
Pressure Switch and Venting
Inspect the pressure switch for proper operation. Test continuity with a multimeter. Clean or replace the switch if faulty.
Check venting pipes for obstructions or damage. Clear any blockages and repair or replace damaged sections. Ensure proper slope and support of horizontal runs.
Verify that the inducer motor is functioning correctly. Listen for operation during furnace startup. Clean the wheel if necessary.
Control Board Diagnostics
Observe LED flash codes on the control board. Consult the furnace manual to interpret codes and identify specific issues.
Check for loose or damaged wiring connections on the control board. Tighten or repair as needed. Inspect for signs of heat damage or burned components.
Test voltage outputs from the control board to various furnace components. Replace the board if multiple systems are not receiving proper signals.
Limit Switch Operations
Locate the limit switch near the heat exchanger. Test for continuity with a multimeter. Replace if the switch fails to open or close properly.
Inspect for signs of overheating around the limit switch. This may indicate restricted airflow or a failing heat exchanger. Clean the area and check for proper blower operation.
Verify that the furnace shuts off when the limit switch is manually tripped. This ensures the safety mechanism is functioning correctly.
Preventive Maintenance Tips
Regular maintenance is crucial for keeping Coleman furnaces running efficiently and preventing error codes. Homeowners can perform several simple tasks to maintain their furnace’s performance.
Change the air filter every 1-3 months, depending on usage and air quality. A clean filter improves airflow and reduces strain on the system.
Clean the blower assembly annually. Remove dust and debris from the blower wheel and housing to ensure proper air circulation.
Inspect and clean the flame sensor once a year. A dirty sensor can cause the furnace to shut down unnecessarily.
Check and tighten electrical connections annually. Loose connections can lead to component failures and error codes.
Lubricate the blower motor bearings if required. Refer to the manufacturer’s instructions for proper lubrication techniques.
Keep the area around the furnace clear of clutter and combustible materials. This ensures proper airflow and reduces fire hazards.
Schedule professional maintenance annually. A technician can perform more in-depth inspections and cleanings to prevent potential issues.
Test the thermostat regularly to ensure accurate temperature readings and proper furnace cycling.
Inspect the venting system for any blockages or damage. Clear obstructions and repair any leaks to maintain safe operation.
When to Call a Professional
While some Coleman furnace issues can be resolved through DIY troubleshooting, certain situations require expert assistance. Contact a certified HVAC technician if:
- The furnace repeatedly shuts off or fails to start
- Strange noises persist after basic maintenance
- Unusual odors emanate from the unit
- Error codes remain unresolved after attempting basic fixes
Safety concerns also warrant professional intervention. Call an expert immediately if:
- You smell gas near the furnace
- The carbon monoxide detector activates
- Electrical components show signs of damage or overheating
Complex repairs involving internal components should be left to professionals. This includes:
- Replacing the heat exchanger
- Repairing or replacing the blower motor
- Addressing issues with the control board
Annual maintenance by a qualified technician is recommended to ensure optimal furnace performance and safety. They can identify potential problems before they escalate and perform necessary adjustments or repairs.
Remember, attempting complex repairs without proper knowledge and tools can void warranties and potentially create hazardous situations. When in doubt, it’s always best to consult a professional HVAC technician.
How to Avoid Being Ripped Off and Get a Fair Repair Price
Finding the right furnace repair expert can be tricky—some companies offer rock-bottom prices because they’re inexperienced or have poor reputations, while others charge far too much for the same work. That’s why the smartest way to get quality repairs at a fair price is to compare estimates from top-rated local pros. Meet with each, learn about their history and the experience of the technicians that will do the work. Choose an experienced furnace repair contractor with reasonable rates. You can expedite this process by using our Free Local Estimates service.
When you fill out a quick form and submit it, you’ll soon be contacted by three of the top furnace repair and installation companies near you. They are prescreened for experience, and all are licensed and insured for your protection. Click below to get started and protect your home and wallet today.
Warranty and Support Resources
Coleman furnaces typically come with limited warranties that cover parts and labor for a set period. Warranty terms vary by model, but often range from 5-10 years for major components.
To access warranty service, homeowners should contact their local Coleman dealer. The dealer can assist with troubleshooting and arrange repairs if needed.
Coleman provides several online resources to support furnace owners:
- Product manuals and documentation
- FAQs and troubleshooting guides
- Dealer locator tool
- Registration for extended warranty options
For technical support, Coleman offers a customer service hotline. Trained representatives can help diagnose issues and provide guidance on potential solutions.
Coleman’s website features a parts lookup tool. This allows homeowners to easily find and order replacement components for their specific furnace model.
Many Coleman dealers offer maintenance plans. These can help extend furnace life and may include priority service during peak seasons.
For DIY-inclined homeowners, Coleman provides some instructional videos. These cover basic maintenance tasks and troubleshooting steps for common issues.
