What Is A Code 13 On A Carrier Furnace?

Your Carrier furnace unit is an essential part of setting the right temperature in your home, especially in the winter. But a malfunctioning furnace unit makes it impossible to control or regulate the proper thermal setup. As such, when code 13 appears in the furnace screen panel, you might wonder what causes this to show. We've researched this to find out!

When error code 13 flashes on your Carrier furnace unit's display, the system's limit switch is in lockout mode or the limit switch has tripped. Ten successive high fire or three straight low fire improper cycles cause this. As a result, the control panel will auto-reset the Carrier furnace in three hours upon showing the error code.

Stay tuned! There's tons of vital knowledge relating to other common Carrier furnace error codes. We will also share with you how you troubleshoot your furnace. With that said, let's dive right in!

photo of a carrier furnace on the basement below the house room, What Is A Code 13 On A Carrier Furnace?

What Do Carrier Furnace LED Yellow Light Flashes Mean?

Carrier furnaces have their way of communicating to tell you something's wrong within their system. This might be an error code or via LED light flashes, particularly a yellow light. All of them need immediate evaluation.

If you see a LED yellow light that stays on for a long period, it implies the furnace system is malfunctioning. Perhaps, it is jammed in a high fire state because of a broken gas valve solenoid.

As a result, the furnace is set in high-fire locked mode. The high-fire mode should only be used for brief intervals to quickly warm a severely chilly house. You can fix this by changing your faulty gas valve component.

See this Carrier Gas Valve on Amazon.

How To Replace A Faulty Furnace Gas Valve?

Neglecting this issue could result in various serious problems happening in your furnace unit. Therefore, replacing it is the most practical solution.

First, this procedure may require you to prepare the following things:

  • Pipe wrench.
  • Screwdriver.
  • Masking tape.
  • Adjustable wrenches.
  • Gas-approved pipe thread compound.

Once you have these materials, you can now start the replacing process:

  1. Start by turning OFF the furnace unit power breaker.
  2. Set the furnace shutoff valve to the OFF position using your adjustable wrench and turn it in counterclockwise.
  3. Securely unplug the gas valve's electrical wiring if it attaches via a push-on connector.
  4. Unscrew the screw-on connector in its terminal using a screwdriver. Wrap each wire with masking tape and label each wire for your guidelines later.
  5. Loosen the gas pipe's union fitting using a wrench and turn it in a counterclockwise direction.
  6. Loosen its gas valve's intake by turning it gently counterclockwise.
  7. Using your pipe wrench, again, turn the defective gas valve to remove it.
  8. Inspect your new gas valve to whether it is compatible with your furnace unit according to your labels.
  9. Cover the threads of the gas pipe's burner with an ideal thread compound.
  10. Securely hand-tighten the new gas valve.
  11. Also, wrap the gas valve's intake port with a thread compound before reinserting and tightening the gas pipe.
  12. Insert the union nut onto its fittings and hand-tighten it first before finishing it with an adjustable wrench.
  13. Properly reattach all the gas valve terminal wires in alignment with the gas valve.
  14. Switch "ON" the gas knob and examine it for possible leakage.
  15. If everything goes fine, then turn "ON" the furnace power breaker.

WARNING! Please don't ever make any smoke or sparks when performing this replacement procedure!

What Are The Other Common Error Codes In Your Carrier Furnace Unit?

A carrier furnace has a sensor that can detect ongoing or underlying issues that are present within its system. An LED that flashes indicates a fault code when a system issue arises.

There are plenty of other error codes you may face. However, here we've listed the most common error codes that you might come across:

Furnace Error Code 11

This code will appear if the system didn't sense any faults in five consecutive previous cycles while SW-1 is "ON." You can fix this by accessing your Carrier blower unit and depressing its door switch.

Furnace Error Code 12

This means that the blower motor is spinning in inappropriate cycles. As such, it is spinning at 250 or higher than 1300 rpm in two straight calibration cycles. Turning "OFF" the furnace power and waiting for about 30 seconds will fix it.

However, you can also include resetting the thermostat if somehow still the issue persists. Replacing its motor or module control is your only alternative to solve this problem for good.

Check this Carrier Furnace Blower Motor on Amazon.

Furnace Error Code 13

Your system senses 10 concurrent irregular high fire or three successive low fire cycles while it is running. This is a bit complex issue as it turns out the limit switch is tripped and is in lockout mode during its operation.

Fixing this problem requires resetting the flame roll-out switch and replacing the limit switch and control board.

Furnace Error Code 14

This type of error code is an indication of an ignition lockout due to four straight failure attempts to ignite the gas. Another reason is your gas valve relay is malfunctioning, or the control board has faulty wiring.

photo of a close up fire of the furnace inside blue colored hot flame fire

This is also a very broad issue as this concerns wiring to ensure the job's quality. We strongly advise you to ask for help from your Carrier HVAC specialist directly.

Furnace Error Code 33

This error means that the unit is working in high-heat-only mode. Also, the limit, rollout, or auxiliary limit switches is open as a result of two consecutive low-heat limit excursions. Resetting your furnace unit will solve this kind of issue.

NOTE: This list of error codes may appear so difficult to deal with. However, a certified Carrier technician can easily assess and solve these problems with the assurance of great job results.

How Do You Troubleshoot A Carrier Furnace That Won't Start?

photo of a close up fire heat blue flame orange flame of the furnace

As a homeowner and a Carrier furnace user, knowing how to act accordingly when such problems occur in your furnace unit is vital. While only an HVAC professional can diagnose and pinpoint easily the problems in your furnace.

However, still, some common issues only need a simple troubleshooting step to avoid them from happening.

Follow us below to learn our detailed yet helpful troubleshooting guidelines:

  1. Always keep an eye on your thermostat's battery to ensure it is working with enough power. Mind that the average service life of your thermostat battery is around 8-12 months.
  2. Inspect the thermostat if it is set in the wrong thermal mode; note that it should always be set on "HEAT" mode.
  3. Ensure that the thermostat is running in line with its proper room thermal set point. According to experts, you should set your thermostat at 68° F, especially during the winter season.
  4. Examine the fan switch setup if it is set to "AUTO" mode. If yes, switch it to "ON" mode to avoid facing the issue.
  5. Also, check your fuse box or power breaker to see if your furnace is getting a sufficient power supply to start.
  6. The gas supply knob should look parallel to its gas line. So ensure to set the gas supply to the "ON" position.

WARNING! When troubleshooting your Carrier furnace unit and if you smell a gas leak, do not switch ON the pilot light. Instead, immediately call your gas company and let them check the gas leaking issue.

How Do You Reset A Carrier Furnace Unit?

close up photo of a reset button on a red and blue background at back

Try to reset your Carrier furnace unit before you ask for professional assistance. Remember, it's always worth exerting efforts to restore its operation to normal before consulting an expert.

Resetting your furnace unit doesn't require complex steps and intricate tools. Knowing the process and performing this is the key to your furnace working effectively again.

Here's how you correctly reset your Carrier furnace unit:

  1. Shut OFF your thermostat entirely to avoid activating it while performing this process.
  2. Also, turn OFF the power source of your furnace unit or simply unplug its power cord from the power socket.
  3. Allow the furnace system to rest or reboot for at least around 30 seconds.
  4. Now switch your thermostat ON again.
  5. Followed by turning ON the furnace unit's power or plugging back the furnace's power cord.

To Wrap Up

photo of a carrier furnace on the basement below the house room

Knowing the problem in your Carrier furnace unit's system will determine what exactly caused it to occur. Now that you know what error code 13 in your Carrier furnace unit is, you can fix it correctly and easily.

You can now identify and solve the other basic fault codes that you may come across when operating your furnace. We can now set off with confidence with all this significant knowledge to help you care for your Carrier furnace unit.

If you find this article helpful, read this other useful article below!

Where Is The Flame Sensor On A Carrier Furnace?

How To Open Carrier Furnace Door [In 4 Easy Steps!]

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