Comprehensive Guide to Tempstar Furnace Error Codes and Troubleshooting

Tempstar furnaces are known for reliable heating performance, but like all HVAC equipment, they may encounter error codes indicating operational issues. Understanding these Tempstar furnace error codes is essential for homeowners and technicians to quickly diagnose and resolve problems. This guide explains common error codes, their meanings, and practical troubleshooting steps to restore furnace functionality efficiently.

Error Code	Description	Common Cause	Basic Troubleshooting Step
2 Flashes	Pressure Switch Not Closing	Clogged vent or blocked pressure switch tubing	Inspect and clean vent system and pressure switch tubing
3 Flashes	Pressure Switch Does Not Open	Faulty pressure switch or wiring issue	Test or replace pressure switch and check wiring
4 Flashes	Flame Not Detected	Ignition failure or gas supply issues	Check ignition system and gas valve
5 Flashes	Flame Detected With Gas Valve Off	Gas valve stuck open	Shut down furnace; replace gas valve
6 Flashes	Open High Limit Switch	Overheating due to airflow problems	Clean or replace air filter and inspect blower

Overview of Tempstar Furnace Error Codes

Tempstar furnaces use a sequence of LED flashes to communicate specific error codes. These fault indicators help pinpoint operational issues without needing advanced diagnostic tools. Homeowners who recognize these codes can often take simple corrective actions or provide useful information to service technicians. Each error code corresponds to a particular component or system within the furnace that requires attention.

Common Tempstar Furnace Error Codes and Their Meanings

Understanding the most frequent error codes can prevent unnecessary service calls and ensure safe furnace operation.

2 Flash Error: Pressure Switch Not Closing

This error signals that the furnace’s pressure switch did not close when expected. The pressure switch ensures proper venting by detecting air pressure from the inducer motor. A clogged vent, collapsed vent tubing, or blocked pressure switch tubing can cause insufficient pressure change, leading to this error.

3 Flash Error: Pressure Switch Does Not Open

The furnace expects the pressure switch to open during sequence, and failure to do so can indicate a defective pressure switch or wiring problem. Since the switch protects against unsafe vent conditions, this error requires immediate attention to prevent furnace damage.

4 Flash Error: Flame Not Detected

This code indicates ignition failure. When the furnace attempts to light the burners, the flame sensor must detect a flame. Common causes include an unlit burner due to faulty ignitors, lack of gas supply, or dirty flame sensors. Regular cleaning and inspection alleviate this problem.

5 Flash Error: Flame Detected With Gas Valve Off

Detecting a flame with the gas valve closed is dangerous and suggests that the gas valve is stuck open. This requires immediate furnace shutdown and professional repair to address the gas valve malfunction to avoid fire hazards.

6 Flash Error: Open High Limit Switch

The high limit switch monitors furnace temperature and shuts down the burner if overheating occurs. Blocked airflow, dirty air filters, or blower motor failure can cause overheating, triggering this error. Maintenance such as replacing filters and inspecting blower operation is crucial.

How to Read and Interpret Tempstar Furnace Error Codes

Most Tempstar furnaces feature an LED light indicator near the control board or gas valve. The light flashes a code represented by a specific number of blinks followed by a pause. Count the blinks carefully to determine the exact code.

• Locate the LED indicator on the furnace control board.
• Observe the blinking pattern: count the number of flashes before a pause.
• Compare the blink count with error code charts in the furnace manual or online resources.

Errors may repeat continuously until the underlying issue is resolved or the furnace is reset.

Effective Troubleshooting Steps for Tempstar Furnace Issues

Performing basic troubleshooting can save time before calling a professional. However, always prioritize safety and avoid working with gas components if unsure.

Inspect Furnace Air Filters and Vents

Blocked airflow is a common cause of many furnace errors. Check and replace air filters regularly, and verify that vents and exhaust pipes are clear of obstructions such as debris, bird nests, or snow buildup.

Check Pressure Switch Tubing and Venting

Examine the tubes connected to the pressure switch for kinks or blockages. Ensure the vent pipe is securely connected and free of corrosion or damage.

Clean or Replace Flame Sensor

A dirty flame sensor can prevent flame detection. Cleaning gently with fine sandpaper or a soft cloth often restores sensor performance.

Reset the Furnace

Many errors clear after powering down the furnace for a few minutes. Pressing the reset button on the furnace control board or cycling the thermostat can sometimes resolve temporary issues.

When to Call a Professional HVAC Technician

• Persistent error codes despite resetting
• Gas valve malfunctions or suspected leaks
• Complex electrical or component replacements
• Inability to identify the root cause of the error

Professional technicians have specialized tools and training to safely diagnose and repair Tempstar furnaces.

Preventative Maintenance to Avoid Tempstar Furnace Error Codes

Routine maintenance extends furnace lifespan and reduces error occurrences.

• Replace or clean air filters every 1-3 months depending on usage
• Schedule annual professional furnace inspections
• Keep venting pipes clear of debris and ice
• Ensure proper thermostat settings and operation
• Clean burner assembly and flame sensors annually

Using the Tempstar Furnace Manual and Resources

Refer to the furnace’s owner manual for specific error codes related to each model. Tempstar’s official website and customer support provide downloadable manuals, FAQs, and troubleshooting guides. Online forums and HVAC professionals also offer practical insights specific to Tempstar furnaces.

Summary Table of Tempstar Furnace Error Codes and Actions

Error Code	Meaning	Likely Cause	Recommended Action
2 Flashes	Pressure Switch Not Closing	Clogged vent, tubing obstruction	Clear venting and tubing
3 Flashes	Pressure Switch Does Not Open	Faulty switch or wiring issue	Test switch and wiring
4 Flashes	Ignition Failure – No Flame Detected	Dirty sensor, ignition failure	Clean sensor, inspect ignition
5 Flashes	Flame Detected With Valve Off	Gas valve stuck open	Turn off furnace, call technician
6 Flashes	High Limit Switch Open	Overheating, poor airflow	Replace filters, check blower