Clearing Error Code 223 on Your Lennox® Furnace

Getting cold because you’re getting error code 223 from your Lennox® furnace?

This means your furnace’s low pressure switch is open. Due to the malfunction, your system will not run for your protection.

Turn to the Experts at Atmostemp Service Experts to handle mending this furnace error. Our ACE-certified technicians are among the best in the industry when it comes to diagnosing and repairing furnace problems.

Your satisfaction is essential to us. That’s why we back our furnace repair* for a year.

How a Low Pressure Switch Works

Pressure switches are a necessary part of the heating process.

Here’s how your furnace starts after the thermostat begins to call for heat:

  • Your furnace’s control board begins the draft inducer blower motor. This exhausts combustion gases from the heat exchanger and pulls in new gas and air so the burners can fire.
  • When the pressure switch senses that sufficient air is being pulled into the burners, it closes and signals the control board to ignite the furnace.
  • Your furnace ignites and heats your house.

A two-stage furnace has more than one pressure switches, which allow it to run at multiple speeds—and use energy more efficiently.

What Happens When a Low Pressure Switch Malfunctions

The low pressure switch may be open for a couple reasons.

There could be a:

  • Blocked vent
  • Plugged condensate drain
  • Cracked hose

There could also be an issue with the switch itself, the inducer or the circuit board.

Your furnace will let you know there’s a problem with a red flash from its indicator light, which it uses to display error codes. It has this red light to flash code, like Morse code.

You might notice fast flashes or an alternating slow flash as it replays a fault code.

Estimated Repair Cost for Furnace Error Code 223

The expense to fix your furnace depends on the root problem48} and the time it takes to remedy it.

Here are average replacement costs for several components that could be affected:

  • Pressure switch—$40 to $350
  • Inducer—$600 to $1,500
  • Circuit board—$200 to $600

Call the Experts at Atmostemp Service Experts

When you need furnace service, you can trust the professionals at Atmostemp Service Experts

to handle the fault code and get your heat flowing again.

Call us at or schedule an appointment online today.

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