If you’re a homeowner, chances are you’re familiar with the occasional furnace issue. Furnaces are complicated systems and can be difficult to troubleshoot without the right knowledge. In this article, we’ll give you an overview of the common errors you might encounter with a Lennox furnace and the troubleshooting steps to fix them.

Introduction to Lennox Furnaces

Lennox is a trusted name in home heating solutions. They offer a variety of models, from basic gas furnaces to sophisticated air conditioners. Furnaces from Lennox are reliable and efficient, and provide homeowners with a comfortable and safe heating solution.

However, like all mechanical systems, furnaces can have problems. Before you can troubleshoot your furnace, it’s important to understand how it works. A basic Lennox furnace consists of the following components:

  • Heat exchanger
  • Blower motor
  • Thermostat
  • Gas valve
  • Ignition and pilot light
  • Flame sensor
  • Fan limit switch

When all these parts are working properly, your furnace will provide you with dependable heating. But if one component stops working, the entire system can be affected.

Common Lennox Furnace Errors and Troubleshooting Steps

There are a few common errors you might experience with your Lennox furnace. The first step in troubleshooting is to identify the problem. Here are some common errors and their solutions:

  • Furnace won’t turn on: This could be caused by a tripped circuit breaker, a faulty thermostat, or a problem with the gas valve. Try resetting the circuit breaker, checking the thermostat settings, and making sure the gas is turned on.
  • Furnace won’t stay on: This could be caused by a faulty ignition and pilot light or a problem with the heat exchanger. Check the pilot light and make sure it’s lit, and check the heat exchanger for any cracks or blockages.
  • Furnace is not heating properly: This could be caused by a number of factors, including a dirty air filter, an issue with the blower motor, or a problem with the pressure switch. Make sure the air filter is clean, check the blower motor for any obstructions, and check the pressure switch for any blockages.
  • Furnace is producing strange noises: This could be caused by a faulty blower motor or a problem with the fan limit switch. Check the blower motor for any obstructions, and make sure the fan limit switch is set to the correct setting.

Troubleshooting Heat and Air Flow Issues

The first step in troubleshooting heat and air flow issues is to check the air filter. If the air filter is dirty, it can restrict air flow and cause the furnace to overheat. Make sure the air filter is clean, and replace it if necessary.

If the air filter is not the problem, check the blower motor. The blower motor is what circulates the air through the furnace. If the blower motor is not working properly, it can cause poor air flow and poor heating. Make sure the blower motor is working properly, and check for any obstructions that could be blocking the air flow.

If the blower motor is working properly, check the pressure switch. The pressure switch is what tells the furnace when to turn on and off. If the pressure switch is blocked or faulty, it can cause poor heating and air flow. Make sure the pressure switch is in good working order, and replace it if necessary.

Troubleshooting Ignition and Pilot Light Issues

The pilot light is an important part of the furnace, as it ignites the gas that powers the furnace. If the pilot light is not working properly, it can cause the furnace to not turn on. The first step in troubleshooting ignition and pilot light issues is to check the pilot light. Make sure the pilot light is lit and adjust the flame if necessary.

If the pilot light is lit but the furnace still won’t turn on, check the gas valve. The gas valve controls the flow of gas to the pilot light. If the gas valve is blocked or faulty, it can cause the furnace not to turn on. Make sure the gas valve is in good working order, and replace it if necessary.

Troubleshooting Thermostat Issues

The thermostat is an important part of the furnace, as it tells the furnace when to turn on and off. If the thermostat is not working properly, it can cause the furnace not to turn on or off. The first step in troubleshooting thermostat issues is to check the thermostat settings. Make sure the thermostat is set to the correct temperature and is in the “on” position.

If the thermostat settings are correct but the furnace still won’t turn on or off, check the wiring. Make sure all the wiring is connected properly and is in good working order. If the wiring is faulty, it can cause the furnace not to turn on or off.

Troubleshooting Gas Valve Issues

The gas valve is an important part of the furnace, as it controls the flow of gas to the pilot light. If the gas valve is blocked or faulty, it can cause the furnace not to turn on. The first step in troubleshooting gas valve issues is to check the gas valve. Make sure the gas valve is in the “on” position and is not blocked.

If the gas valve is in the “on” position but the furnace still won’t turn on, check for any obstructions. Make sure there are no obstructions in the line, and check for any blockages in the valve itself. If the valve is blocked or faulty, it can cause the furnace not to turn on.

Troubleshooting Blower Motor Issues

The blower motor is an important part of the furnace, as it circulates the air through the system. If the blower motor is not working properly, it can cause poor air flow and poor heating. The first step in troubleshooting blower motor issues is to check the motor itself. Make sure the motor is in good working order and that there are no obstructions blocking the air flow.

If the blower motor is working properly, check the fan limit switch. The fan limit switch is what tells the furnace when to turn the blower motor on and off. If the fan limit switch is blocked or faulty, it can cause the blower motor not to turn on or off. Make sure the fan limit switch is set to the correct setting, and replace it if necessary.

Troubleshooting Heat Exchanger Issues

The heat exchanger is an important part of the furnace, as it helps to transfer heat from the furnace to the air in your home. If the heat exchanger is not working properly, it can cause the furnace not to heat properly. The first step in troubleshooting heat exchanger issues is to check the heat exchanger itself. Make sure there are no cracks or blockages in the heat exchanger, and check for any obstructions that could be blocking the air flow.

If the heat exchanger is in good working order but the furnace still isn’t heating properly, check the blower motor. Make sure the blower motor is working properly, and check for any obstructions that could be blocking the air flow. If the blower motor is not working properly, it can cause poor air flow and poor heating.

Troubleshooting Pressure Switch Issues

The pressure switch is an important part of the furnace, as it tells the furnace when to turn on and off. If the pressure switch is blocked or faulty, it can cause the furnace not to turn on or off. The first step in troubleshooting pressure switch issues is to check the pressure switch itself. Make sure the pressure switch is in good working order and that there are no obstructions blocking the air flow.

If the pressure switch is in good working order but the furnace still won’t turn on or off, check the wiring. Make sure all the wiring is connected properly and is in good working order. If the wiring is faulty, it can cause the furnace not to turn on or off.

Troubleshooting Flame Sensor Issues

The flame sensor is an important part of the furnace, as it tells the furnace when the pilot light is lit. If the flame sensor is blocked or faulty, it can cause the furnace not to turn on. The first step in troubleshooting flame sensor issues is to check the flame sensor itself. Make sure the flame sensor is in good working order, and adjust the flame if necessary.

If the flame sensor is in good working order but the furnace still won’t turn on, check the gas valve. Make sure the gas valve is in the “on” position and is not blocked. If the gas valve is blocked or faulty, it can cause the furnace not to turn on.

Troubleshooting Fan Limit Switch Issues

The fan limit switch is an important part of the furnace, as it tells the furnace when to turn the blower motor on and off. If the fan limit switch is blocked or faulty, it can cause the blower motor not to turn on or off. The first step in troubleshooting fan limit switch issues is to check the fan limit switch itself. Make sure the fan limit switch is set to the correct setting, and replace it if necessary.

If the fan limit switch is set to the correct setting but the blower motor still won’t turn on or off, check the blower motor. Make sure the blower motor is working properly, and check for any obstructions that could be blocking the air flow. If the blower motor is not working properly, it can cause poor air flow and poor heating.

Conclusion

Troubleshooting your Lennox furnace can be a daunting task, but with the right knowledge it can be done quickly and easily. In this article, we’ve given you an overview of the common errors you might encounter with a Lennox furnace and the troubleshooting steps to fix them.

If you have any further questions or need help troubleshooting your Lennox furnace, contact us. Our team of experienced technicians is here to help you get your furnace back up and running in no time.