York Furnace Troubleshooting Manual & Guide


If you own a York furnace, there may come a time when you encounter some issues. The good news is that most of these issues are easily fixable and don’t require calling in a professional. 

In this guide, we’ll cover common issues that you may experience with your York furnace and how to fix them.

York Furnace Troubleshooting Manual & Guide: Common Problems & Fixes

york furnace troubleshooting


York Furnace Not Igniting

  • Check the thermostat: Make sure your thermostat is set to “heat” and that the temperature is set high enough to trigger the furnace to turn on.
  • Check the power: Verify that the power switch for your furnace is in the “on” position and that the circuit breaker for your furnace hasn’t tripped.
  • Check the gas supply: Ensure that your gas supply is turned on and that the gas valve supplying your furnace is in the “on” position.
  • Check the ignitor: If your furnace is equipped with an electronic ignitor, make sure that it’s not faulty or damaged. A malfunctioning ignitor may not be producing the necessary spark to ignite the gas.
  • Check the flame sensor: A dirty or malfunctioning flame sensor can also prevent your furnace from igniting. If the flame sensor is dirty, you can clean it with a soft-bristled brush or emery cloth.

York Furnace 3 Red Flashes

  • Check the pressure switch: The pressure switch ensures that there’s proper airflow in your furnace. If the pressure switch is faulty or clogged, it may not be able to detect the correct airflow, causing the furnace to shut down. Check the tubing leading to the pressure switch for any blockages or obstructions. You can also use a multimeter to test the pressure switch for continuity.
  • Check the inducer motor: The inducer motor is responsible for drawing air into the furnace and creating the necessary pressure for the pressure switch to operate correctly. If the inducer motor is faulty or not functioning correctly, it can cause the pressure switch to trip.
  • Check the exhaust vent: If your exhaust vent is blocked or obstructed, it can prevent proper airflow, causing the pressure switch to trip.

York Furnace 4 Red Flashes

  • Check the air filter: A dirty or clogged air filter can restrict airflow, causing the furnace to overheat and trip the high-limit switch. Make sure to change your air filter regularly to prevent this issue.
  • Check the blower motor: The blower motor circulates air throughout your furnace. If it’s not functioning correctly, it can cause the furnace to overheat and trip the high-limit switch.
  • Check the heat exchanger: A cracked or damaged heat exchanger can also cause the furnace to overheat and trip the high-limit switch. If you suspect a problem with your heat exchanger, it’s best to call in a professional to diagnose and repair the issue.

York Furnace Not Blowing Hot Air

  • Dirty air filters: If your air filters are clogged with dust and debris, it can cause restricted airflow, which prevents hot air from circulating throughout your home. Solution: Clean or replace your air filters regularly, preferably every three months.
  • Faulty thermostat: If your thermostat is not functioning correctly, it can prevent your furnace from receiving the signal to heat up your home. Solution: Check your thermostat settings and batteries. If that doesn’t work, replace the thermostat.
  • Faulty igniter: If your furnace igniter is malfunctioning, it can prevent your furnace from starting up and heating your home. Solution: Hire a professional technician to replace the igniter.

York Furnace Not Staying Lit

  • Dirty flame sensor: If your flame sensor is coated in dirt or debris, it can’t detect the flame, which causes your furnace to shut down. Solution: Clean the flame sensor using a soft cloth or hire a professional technician to do it for you.
  • Clogged condensate drain: If your furnace’s condensate drain is clogged, it can cause water to back up and extinguish the flame. Solution: Clear the condensate drain or hire a professional to do it for you.
  • Faulty thermocouple: If your thermocouple is damaged or faulty, it can’t detect the flame, which causes your furnace to shut down. Solution: Hire a professional technician to replace the thermocouple.

York Furnace Not Getting Gas

Gas valve turned off: It might sound obvious, but sometimes the gas valve can be accidentally turned off, which prevents gas from reaching your furnace. Solution: Check the gas valve and turn it back on.

  • Clogged gas line: If your gas line is clogged with dirt or debris, it can prevent gas from reaching your furnace. Solution: Hire a professional technician to clean your gas line.
  • Faulty gas valve: If your gas valve is damaged or faulty, it can prevent gas from reaching your furnace. Solution: Hire a professional technician to replace the gas valve.

York Furnace Error Codes, Meanings & Fixes

If your York furnace is displaying an error code, it’s trying to tell you something isn’t quite right. Here are some common error codes you may encounter:

  • LED code “1 flash” – This indicates a problem with the furnace’s ignition system. Check to make sure the gas valve is turned on and that there are no obstructions in the furnace’s flue.
  • LED code “2 flashes” – This error code points to a problem with the furnace’s pressure switch. Check the vent pipe for obstructions and ensure that the inducer motor is operating properly.
  • LED code “3 flashes” – This error code indicates a problem with the furnace’s limit switch. Check to make sure the air filter is clean and that the blower motor is operating correctly.
  • LED code “4 flashes” – This code indicates an issue with the furnace’s rollout switch. Check for a blocked or restricted vent pipe and make sure the heat exchanger is not cracked.
  • LED code “5 flashes” – This error code points to a problem with the furnace’s flame sensor. Clean the sensor and check the wiring for any loose connections.

York Furnace Reset Button Location

To locate the reset button:


  • Turn off the furnace: Before you start searching for the reset button, turn off your furnace’s power supply. This is a safety precaution that will prevent any accidents from happening.
  • Locate the blower motor: The blower motor is usually located near the bottom of the furnace. Look for a metal cover that can be removed to access the blower motor.
  • Look for the reset button: Once you’ve located the blower motor, look for a small red or yellow button on the side of the motor. This is the reset button.
  • Press the reset button: Once you’ve found the reset button, press it and hold it down for about five seconds. This should reset the furnace.
  • Turn the furnace back on: After resetting the furnace, turn the power supply back on and wait for the furnace to start up again.

York Furnace Pilot Light Explained

The pilot light is an essential component of your York furnace. It’s the small flame that ignites the gas burners and starts the heating process. If your furnace isn’t producing heat, the pilot light may be out. Here’s how to check:

  • Turn off the furnace: As with resetting the furnace, turn off the furnace’s power supply before you start working on the pilot light.
  • Locate the pilot light: The pilot light should be near the bottom of the furnace. You will find a small metal cover that can be removed to access the pilot light.
  • Check the pilot light: Once located, check to see if it’s lit. If it’s not, follow the next steps.
  • Light the pilot light: To light the pilot light, turn the gas valve to the “off” position and wait for a few minutes for any gas to dissipate. Then, turn the gas valve to the “pilot” position and press down on the reset button. While holding down the reset button, light the pilot light with a match or lighter. Keep holding down the reset button for about a minute until the pilot light stays lit.
  • Turn the furnace back on: After lighting the pilot light, turn the gas valve back to the “on” position and turn on the furnace’s power supply. The furnace should start up again and begin producing heat.

York Furnace Flame Sensor Location

The flame sensor in your York furnace detects whether or not the burners are lit. A faulty flame sensor will cause issues with the furnace. Here’s how to locate the flame sensor on your York furnace:

  • Turn off the power to your furnace by flipping the switch on the circuit breaker that controls it.
  • Locate the burner assembly inside your furnace. The flame sensor is located near the burners, but the exact location may vary depending on the model of your furnace.
  • Look for a small metal rod with a ceramic base. This is the flame sensor. It may be mounted on a bracket or simply held in place by a screw.
  • Carefully remove the flame sensor from its bracket or screw. Be gentle, as the sensor is delicate and can be easily damaged.

York Furnace Pressure Switch Location

The pressure switch detects whether or not the blower is functioning properly. If the switch fails, the furnace may not start at all or may shut down shortly after starting. Follow these steps to locate the pressure switch on your York furnace:

  • Turn off the power to your furnace by flipping the switch on the circuit breaker that controls it.
  • Locate the blower assembly inside your furnace. The pressure switch is typically located near the blower, but the exact location may vary depending on the model of your furnace.
  • Look for a small plastic or metal box with wires attached to it. This is the pressure switch.
  • Carefully remove the pressure switch from its mounting bracket or screw. Be gentle, as the switch is delicate and can be easily damaged.