Bryant Furnace Error Codes – Troubleshooting guide

Is there something wrong with your Bryant furnace? 

Fortunately, the smart unit is going to ‘tell’ you what exactly is happening with the help of an error code. The great news is that there are quite a few issues that you’ll be able to fix on your own.

Simply follow the instructions provided below. 

The Complete List of Bryant Furnace Error Codes

Like a lot of other manufacturers, Bryant uses LED lights to indicate an error code.

If something ever goes wrong, you are going to see either an LED light of a certain color or a two-digit code (short and long flashes respectively). Consult our list to find out what’s going on.

Red LED1 On

The furnace is running in emergency heat.

If you did not activate this mode yourself, then the red light might be signalizing that there is a serious problem with your unit. In such a case, the only thing that you can really do is call a professional. 

Your system has such an ‘emergency heat’ setting for the times when it gets extremely cold outside. If the temperature falls below 35 F, the furnace might not be able to keep up and then you can activate the emergency heat.

This mode will be able to get you through the freezing night, but it is not something that should be constantly on. Emergency heat will not only make your energy bills skyrocket, but it will also put a strain on the whole system.

While waiting for the technician, you can inspect your furnace and check the components for damage. For example, a tree could have fallen and crushed the unit or there might be a leak that had formed into ice.

Red LED2 On

The microprocessor did not run correctly. 

Some furnaces have microprocessors that monitor the temperature of each room and control the operation of the system. 

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If you see such an error code, then you would have to reset the unit

  1. Find the SW-1 set-up button and twitch it to ‘on’ and jumper the thermostat terminals R, W/W1, Y/Y2 (at the same time with the door button pushed in). The power to the furnace should be on.
  2. Disconnect the jumper and twitch the set-up button to the ‘off’ position.

Warning! If the same LED appears again, you would have to get a new control board. 

Yellow LED3 On

The furnace is operating in high heat. 

If you are a lucky owner of a two-stage furnace, then you should know that your unit has two heat settings – low-heat and high-heat.

The majority of the time, the furnace will be operating in low-heat mode, but when it becomes very cold outside, the unit can switch to the high-heat setting.

Simply bear in mind that your furnace is working nearly at its full capacity if you ever see the yellow LED. 

Read: Two-Stage Furnace – What Are Pros And Cons?

Green LED4 On

The furnace is running in low heat.

Red LED2 Flashing

It looks like the line voltage polarity is reversed

If the power to the furnace is reversed, it means that the hot line is neutral and the neutral line became hot.

Try to remember if there have been any changes made in your house wiring lately. 

In any case, checking if a wrong polarity does actually exist is the first thing to do.

Sometimes, a red LED might be flashing, if there is a problem with the circuit board. Unfortunately, the chances are high that you would have to replace the board. 

Error Code 1-1

There were no faults in the last five cycles.

To go through the fault history, simply twitch the set-up switch to ‘on’. To clear the history, repeat the previous step and jumper the thermostat terminals R, W/W1, and Y/Y2 at the same time.

Error Code 1-2

The code indicates a blower calibration lockout

This means that the Revolutions per Minute (RPM) of the blower were either less than 250 or more than 1300.

Fact: the most common RPMs are 900 and 1200.

The system will auto-reset in 3 hours, but you would have to reset the power on your own (you can simply reset the circuit breaker in your house). 

Error Code 1-3

A limit switch lockout.

This means that the switch had tripped 10 times in a row in high-heat or 3 times in low-heat. The system will auto-reset in 3 hours.

The things that you can inspect include:

  • The actual limit switch
  • The gas pressure in and out of the gas valve
  • The gas valve (it can be stuck)

Error Code 1-4

Ignition lockout.

The furnace is going to reset automatically in 3 hours, but why did this lockout happen in the first place?

  • A defective flame sensor – it might be faulty or simply dirty.
  • A faulty igniter
  • A limit switch response – a dirty filter, for example, can cause the limit switch to trip.

Read: How Long Do Flame Sensors Last?

Error Code 2-1

Invalid model selection.

It looks like the model plug is either incorrect or missing.  You can check the wiring diagram to find out if all the connections are in place.

If your thermostat has a jumper wire, check that one as well (this wire doesn’t go through the wall, it connects two terminals together).

Error Code 2-2

A set-up error.

Either switch SW-1 or SW-6 is not positioned properly.

These are the combinations that will cause the error to appear:

  • Thermostat call with SW-1 on.
  • Thermostat call with SW-6 on.
  • Thermostat call with both SW-1 and SW-6 on.

Read: Why Does Home Thermostat Say HEAT ON But There Is No Heat?

Error Code 2-3

An invalid blower airflow selection.

If you see this code, the unit will default to the closest allowable airflow. 

Every model has a certain tonnage and a CFM range. The switch settings weren’t right and the furnace wasn’t able to operate in the right range, that’s why the error took place.

Read: Furnace Filter Airflow – What You Need To Know?

Error Code 2-4

The secondary voltage fuse is open.

Inspect the secondary voltage wiring – there might be a shortcut.

Error Code 3-1

The pressure switch did not close or it reopened.

If the switch has been open for over 5 minutes, then the system is going to shut off for 15 minutes.

A pressure switch is a safety component that is located next to the motor. It shuts the unit down if it senses negative pressure.

There are quite a few things that can cause this error code to appear:

  • Strong wind
  • A defective inducer motor
  • Improper combustion air supply
  • A faulty pressure switch (it might be dirty, damaged, or simply too old)
  • An obstruction in the pressure tubing

Read: What Does A Pressure Switch Do On A Furnace?

Error Code 3-3

The limit or flame rollout is open.

Fact: if the opening lasts for over 3 minutes, the unit will go into lockout (error code 1-3).

You would have to manually reset the flame rollout switch.

Do bear in mind that the problem could have been caused by:

  • A restricted vent or a vent of an improper size
  • A loose blower wheel
  • Improper combustion air supply
  • A dirty filter
  • A defective blower motor, switch, or capacitor

Error Code 3-4

Failed ignition.

The system will try to start the cycle 3 more times and will then go into lockout (code 1-4). 

You might have a dirty flame sensor, a faulty gas valve, low inlet gas pressure, a defective hot surface ignitor.

Error Code 4-1

The blower isn’t working at the right RPM.

Check the wiring to the motor.

Error Code 4-2

The inducer isn’t working at the right RPM.

Once again, check the wiring to the motor.

Error Code 4-3

A pressure switch calibration fault.

You might want to call in a professional who is going to calibrate the switch for you.

However, you can still check for:

  • An unplugged condensate drain
  • Water in the piping
  • Improper connection in the switch
  • A faulty pressure switch

Error Code 4-4

A blower calibration fault.

This means that the blower speed is either below 250 or over 1300 RPM.

Check the wiring to the motor, if this code appears together with code 4-1. In all the other cases, make sure that the ductwork is not undersized, that the registers aren’t closed, and that the filters are clean.

Error Code 4-5

A control circuity lockout. 

The system will auto-reset in around 1 hour.A stuck gas valve, a software check error, or a flame sense circuit failure might be to blame. You may have to manually reset the unit or even get a new control if the error appears again.

Read: American Standard Furnace– Troubleshooting Guide