Bryant Furnace Code 33 [Solved]

In this troubleshooting guide, we’ll walk you through the causes for the Bryant furnace code 33, and the measures you can take to reset this error code and get your system back up and running.

The Bryant furnace code 33 indicates that a limit or flame rollout switch is open. This could occur due to Overheating in the furnace caused by insufficient airflow or the furnace operating only  in high-heat mode. 

The blower will remain active for 4 minutes or until the switch resets, whichever duration is greater. If the switch remains open for over 3 minutes, the code will transition to lockout  code 13.

 Alternatively, if the switch remains open for less than 3 minutes, the status code 33 will continue to flash until the blower deactivates.

PS: See also embedded video on troubleshooting Error Code 33 near bottom of this guide

Read also: Carrier Furnace Code 33 [Fixed]

Common   Causes For Bryant Furnace Code 33

Dirty filter or restricted duct systemReplace filter
Restricted vent/ grilles and registersOpen up closed/blocked vents
Loose blower wheel
Defective blower motor or capacitor. Replace capacitor or blower motor
Defective LimitReplace limit switch

Dirty air filter

A dirty or clogged air filter is a frequent cause of overheating and can activate code 33 in Bryant furnaces.

If your furnace displays code 33, the initial step to take is examining the air filter. Locate the air filter near the blower compartment and assess its condition.

If it appears dirty or if more than 2 months have passed since the last replacement, it’s advisable to install a new one.

When the air filter is dirty, it restricts airflow, leading to overheating within the furnace, which consequently can prevent  the limit switch to close thus triggering  code 33.

Read also: Furnace Shuts Off After 30 Seconds [Fixed]

Closed Vents/Grilles or registers

If there are too many vents or grilles that are closed or blocked, they prevent hot air from going out, and this puts a lot of pressure on the furnace and causes overheating.

Ensure that you have enough vents open, also check that there are no objects such as furniture, rugs, and mats blocking the vents.

Another air restriction in the ductwork could be due to pinched or twisted ducts. You might want to inspect your duct for any abnormalities such as twisted or pinched ducts that would restrict the hot air from going out.

Read also: Carrier Furnace Code 34 and 14 [Fixed]

Defective blower or capacitor

A malfunctioning blower motor or capacitor can result in heating issues within the furnace system, leading to the activation of status code 33.

The furnace blower operates by drawing air from the return vent and propelling heated air through the ductwork, distributing warmth throughout your home.

When the blower fails to function, there will be no circulation of hot air, resulting in overheating. This, in turn, triggers the limit switch to trip.

Read also: Goodman Furnace 4 Flashes [Solved]


In the event of a faulty blower motor, replacement with a functional unit is necessary. Additionally, it is advisable to replace the motor capacitor as it is likely to malfunction over time.

To troubleshoot the blower motor, start with  testing of the capacitor first . The capacitor stores the required energy for motor startup. Use  a multimeter to assess capacitor continuity. 

You can check out this youtube video

If the capacitor tests out fine, there exists a possibility of the blower motor being defective. You  can try to spin it  manually to  determine this; if there is resistance, the motor may be faulty. 

A malfunctioning motor often gets too hot when you turn on power  and may produce an abnormal humming noise.

Read also: Bryant Furnace Code 31 [Fixed]

Defective limit switch

A limit switch functions as a small safety device, responsible for shutting off the furnace in instances of furnace overheating.

Over time, a limit switch is susceptible to wear, much like any other device.

It consists of two different metals (bimetallic), and during overheating, it bends to the other side, interrupting the circuit. With frequent occurrences, it can become lodged in the open position, triggering status code 33.

If you suspect your limit switch is stuck open, attempt to gently nudge it with a screwdriver or a similarly small, solid object. If this method doesn’t work for you, consider  replacing the limit switch assembly.

Final thoughts

To wrap it up, the most important thing you need to know about the Bryant furnace code 33 is that it’s mainly caused by overheating or a defective limit switch. If the issue persists for more than 3 minutes, it’s what will result in code 13.

It’s also a good idea to always call for professional help if you are unable to fix or pinpoint the real cause of the problem.

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