Bryant Furnace Code 33 – Easy Steps To Diagnose

If you see your Bryant furnace’s lights flashing, it looks like the unit is trying to tell you something. Never ignore furnace codes as they give you critical information regarding a potentially serious problem.

Bryant furnace code 33 (3 short flashes and 3 long flashes) indicate a limit circuit fault – this means that the high limit switch has been open. Such an error can appear if there’s a lack of airflow; changing the filter, opening the vents, and getting rid of any obstructions in the duct should help.

What Does A Bryant Furnace Code 33 Mean?

Error codes might mean different things in different furnace models. However, if you have a Bryant, Carrier, or Payne furnace, code 33 means open limit.

It is a temperature-related issue that generally indicates an issue with the airflow. It senses that there is not enough air moving through the furnace and the unit is cycling on the limit control.

In such a case, the system will most likely turn off the fuel to prevent the unit from overheating.

furnace fuel valve

Read: Bryant Furnace Error Codes – Troubleshooting Guide

Error 33 or the ‘limit circuit fault’ indicates that the flame rollout or high limit switch has been open. If not taken care of, the issue can lead to error code 13 – ‘limit circuit lockout’. See below for more on error code 13.

The high limit switch is your furnace’s safety device that is there to shut off the burner in case the temperature gets way too high in the air plenum.

When you see this code, lack of airflow or insufficient airflow is usually the root cause of the problem. Airflow issues, in their turn, can be caused by:

  • A clogged air filter
  • An obstruction in the air duct
  • Closed or blocked air vents
  • A faulty blower motor

Read: Best Furnace Flame Sensors

Bryant furnace code 33

How Do You Fix A Bryant Furnace Code 33?

There are two things that you can do to take care of the issue – improve the airflow and check the actual switch for proper functioning.

Have a Question? Ask HVAC Technician

Click here to use the chatbox to speak with one of our technicians.
No in-home service calls. No appointments.

When it comes to the high limit switch, you would have to check the element for continuity. If the flame rollout switch had tripped, then check for a blocked flue and backdrafts.

Read: How Do I Know When My Air Ducts Need Cleaned?

Furnace flue and ducts

Airflow issues are, in general, a lot easier to fix:

  • Replace the filter, if it’s dirty
  • Open all return registers and vents
  • Clean the register grilles and ducts
  • Check the blower wheel (clean it, if necessary, and tighten any wobbly blades)
  • Check the blower motor 
  • Make sure that there is proper combustion air. If you have a 90% furnace – check the PVC pipe; for 80% furnaces – make sure that the unit is getting enough air, especially, if it’s located in a closet.

Read: Is It Ok To Have A Furnace In The Crawl Space?

What Is Code 13 on a Bryant Furnace?

If the high limit switch stays open for over 3 minutes or the limit switch has been tripped 10 times in a row during high-heat, then you will see error code 13 – ‘limit circuit lockout’. The furnace will try to restart itself in 3 hours.

What Causes Limit Circuit Lockout?

Your Bryant furnace will show code 13 if there is a limit circuit lockout. This either means that the high limit switch has been tripped 10 times in high-heat or 3 times in low-heat.

You would have to wait for the system to reset itself in 3 hours.

The most common causes for such an issue include:

  • A faulty limit switch
  • Insufficient airflow
  • A stuck or malfunctioning gas valve
  • A pressure issue in and out of the gas valve

Bryant Furnace Limit Switch

The exact location of the limit switch would depend on the model of the furnace. However, in general, the element can be found in the hot-air supply plenum, right above the heat exchanger or combustion chamber.

How Do You Fix Code 13 on a Bryant Furnace?

Make sure that nothing is blocking the airflow to the furnace.

Also, the unit might be overheating because there is something wrong with the blower. 

If the blower is getting 115V but is not working, then your blower has gone bad. If the blower is not getting power, then your circuit board is to blame. 

How Do You Read a Furnace Error Code?

If you have a smart thermostat and an error occurs, then all you would have to do is read the number of the code on the thermostat’s screen and find what it means in the owner’s manual.

The actual furnace, in the majority of cases, will use a system of blinking lights to tell you what is wrong. You’ll find the LED display either on the unit or mounted to the circuit board.

furnace blinking lights

Make sure to note how many times the light had blinked and how fast the flashing occurs (slow and fast blinking would mean completely different things).

With a Bryant furnace, the short flashes indicate the first digit, and the long flashes – the second digit. In the end, you should have a two-digit number (like 33, for example).

Read: How To Choose Furnace Filter?

How Do You Reset the Code on a Bryant Furnace?

You should take any error code seriously as it indicates a malfunction in the heating system. The code will automatically go away as soon as you take care of the issue. There is no resetting procedure to worry about.

That said, if you want to speed up the reset process, turn power off to the furnace for a few minutes before turning it back on. Sometimes this can help force the furnace to run its automatic self-checks sooner.

Other Related Bryant Furnace Codes

Bryant Furnace LED Codes – 2 Short, 2 Long

If you get a 2-2 error code (2 short flashes and 2 long flashes), this indicates an invalid blower airflow selection.

The unit will switch to the closest allowable airflow. Basically, the code means that the initial settings weren’t right and that the furnace wasn’t able to operate in the specified range.

Fact: Every furnace model has a certain CFM (cubic feet per minute) range and tonnage rating.

What Does A Solid Yellow Light on A Bryant Furnace Mean?

Bryant furnace solid yellow light

Usually, only two-stage furnaces would have a yellow light. If the LED is on, it means that your unit is operating in high-heat mode.

The majority of the time, the system will be working in a low-heat mode, but if it gets extremely cold outside or the desired temperature is very high, the furnace will switch to its high-heat setting.

Basically, the yellow light means that everything is okay, but you should be aware that the unit is operating nearly at its full capacity.

What Does a Solid Red Light on My Bryant Furnace Mean?

A solid red light can mean two things.

Either the furnace is operating in emergency heat or the microprocessor is not operating correctly

Basic Furnace Troubleshooting

Here are a few things that you can do to quickly troubleshoot your furnace:

  1. Turn the thermostat 5 degrees higher than the current temperature.
  2. If the furnace did not kick in, then check the breaker box.
  3. Find the gas valve (it’s usually located on the back of the furnace). Turn the valve to OFF and wait for 5 minutes; if you smell gas, call the gas company right away.
  4. Check the furnace filter and replace it, if it’s dirty.
  5. Check the bottom of the furnace. If it’s covered in dust, then use a damp cloth to clean the bottom of the unit and the vents and grilles around it.
  6. Make sure that there is nothing blocking the ventilation to the furnace

Doing these few things can sometimes nip other issues in the bud, before they become big problems. Remember, like with any troubleshooting, always check the easiest, most obvious things first.

Read: How Often Do I Need To Change My Furnace Filter?

How Do I Read My Bryant Model Number?

You can go directly to Bryant’s website to figure out the model number. Or you can always remove the unit’s front door and find a rating plate or decal with the number printed on it.

Sometimes this will be located on the inside wall of the furnace. Other times, it will be on the inside of the door panel. If you’re lucky, you have a model that displays all the information on the outside of the door panel, and you don’t need to open it up at all.

Read: Why Furnace Stops Working At Night?

How Do You Manually Reset a Furnace?

If your Bryant furnace has a reset button, it should be located somewhere near the blower motor. Locate a small silver box; right above it, you should see a red or white button – this is a blower reset switch.

Make sure to turn the unit off at the circuit breaker and give the furnace enough time to cool down before searching for the reset button. You don’t want the furnace to suddenly kick on while you’re poking around in there!

Once it’s cool enough to touch, reach in and press the reset button. Then turn the breaker back on, turn up the thermostat, and wait for the unit to kick on.

Final Thoughts

To sum up, the Bryant furnace error code 33 denotes an open limit related to restricted airflow that causes overheating. There are several reasons why airflow could be impeded, so you may need to check several components in order to find the actual culprit. With the guide above, you should be able to narrow it down fairly easily.