Carrier Furnace Ignition Lockout – What To Do?

Having a furnace that stops heating can be a disaster, especially when the weather outside your house is extremely cold. When your Carrier furnace goes into lockout mode. You might wonder about what's the right thing to do to handle this issue. Wonder no more! We researched on the internet to assist you in getting the answer you deserve.

When your Carrier furnace is in ignition lockout, you may need to inspect some of its components. Inspect them thoroughly to see whether they only require cleaning or replacement.

These are the common parts of the Carrier furnace that might need maintenance to fix this issue:

  • Igniter.
  • Air filter.
  • Air Vents.
  • Limit switch.
  • Flame sensor.

That was easy, wasn't it? Well, continue reading because there's tons of information waiting for you below. We will walk you through the types of ignition lockout and what causes it to occur, and much more. Follow us below!

Person changing an clean air filter on a high efficiency furnace, Carrier Furnace Ignition Lockout - What To Do?

What Does Ignition Lockout Mean In Your Furnace?

Ignition lockouts come in two distinct types soft and hard lockouts. A furnace can experience both soft and hard lockouts. Essentially these types of ignition lockout refer to cutting all power to the furnace unit.

A home high energy efficient furnace in a basement

Today, Carrier furnaces use specific sensors within their system to detect any abnormal status. Each of these sensors transmits a signal to the furnace console if it detects an issue or a dangerous situation.

The reason for locking out the control of your furnace is to eliminate any serious risks that might potentially occur. Regardless of the cause, the furnace won't change the ignition lockout mode until it's successfully reset.

When Does A Furnace Go Into Soft Or Hard Lockouts?

Throughout the service of your furnace unit, you will surely come across an ignition lockout. Understanding the reason why these specific issues might occur helps you avoid facing the problem.

When your furnace is in a "soft lockout," it will still allow you to try to restart your furnace unit. In contrast, if it still doesn't kick on after four straight trials, the furnace will go into a "hard lockout."

This means you can no longer operate your furnace unit within three hours. Usually, it indicates that you have improper wiring or that the gas valve relay itself is malfunctioning.

What Causes My Carrier Furnace Ignition Lockout?

Your furnace setting into an ignition lockout results from a series of failures to ignite its burner. There are several defective parts to blame in this regard. However, most of them are the product of ignoring regular service.

Here are some main causes of ignition lockout and how you deal with them correctly:

Faulty Flame Sensor

A faulty flame sensor is one of the main reasons for triggering an ignition lockout. Its function is to check if there is a flame before turning on your furnace igniter. If the sensor is broken, it won't be able to sense the flame.

Thus the system will halt the igniting process and lock its system entirely, securing it from further damage. Inspect the flame sensor condition properly, whether it only needs cleaning or replacement, to avoid this issue.

Visit this Flame Sensor on Amazon.

Broken Igniter

Gas burning in a heating appliance

Another common cause of ignition lockout in your Carrier furnace is running it with a broken igniter. The flame sensor won't engage if your furnace's igniter does not light within a few seconds.

Have a look at this Carrier Igniter on Amazon.

This could also occur even if you're using a pilot light. Your best action to remedy this problem is to replace your broken igniter.

Unresponsive Limit Switch

Your furnace unit has a limit switch that keeps an eye on air pressure and heat transfer temperatures.

The limit switch will shut off the gas supply pipes if the temperature or pressure is too high or too low. You cannot regulate proper pressure and temperature if this device becomes bad, so replacing it helps fix this issue.

Search this dependable Limit Switch on Amazon.

What Causes The Limit Switch To Trigger Ignition Lockout?

Broken or defective parts in your heating system are major causes of ignition lockout. However, there are other factors that you need to address regarding this issue to fully avoid it.

Dirty Air Filter

Replacing the filter in the furnace

A dirty air filter in your furnace unit is the other reason that contributes to why its system goes into ignition lockout. As we've tackled above, proper airflow is necessary for the limit switch to function in line with your furnace.

Operating your furnace unit with a dirty filter hinders the ideal airflow circulation, resulting in your limit switch tripping and eventually locking out your system. It's vital to replace a dirty HVAC filter in your home every 30-60 days.

See this Carrier Furnace Filter on Amazon.

Air Duct Leakage

A ventilation cleaner man at work with tool

Remember that limit switches' jobs are to ensure that your furnace system has sufficient air pressure and thermal level flow. Sealing your ducts will not only solve this problem but boosts the system's overall efficiency by about 20%.

How Do You Know If Your Limit Switch Is Going Bad?

Closeup of heater exhaust fan inside of furnace

Determining whether your furnace unit's limit switch has gone bad or not is essential to keep your furnace working efficiently. Since the limit switches run to monitor the gas pressure and temperature output inside its system.

Connecting a digital multimeter to the limit switch can evaluate and precisely tell if it is defective or not. Moreover, the operating standard voltage reading of the limit switch is 0.1 volts of direct current VDC or less.

Check this reliable Multimeter on Amazon.

However, your limit switch is probably broken if the voltage loss reading is in 0.2 VDC or more. Note that, over time, the contacts of your limit switch may get rusty, wear out, or break.

How Do You Reset A Carrier Furnace Unit?

An ignition lockout fault in your Carrier furnace unit can easily solve by performing a simple resetting process. It's not a bad idea to try to fix your furnace before consulting your HVAC technician.

Of course, as long as you can perform the critical procedures in your particular situation a DIY repair should be no problem.

Here below we've tallied the easy steps for resetting your Carrier furnace:

  1. Go to your thermostat and ensure to shut it "OFF." This is for security purposes in case it accidentally switches "ON" while you're resetting your furnace.
  2. Shut "OFF" your furnace unit's power breaker, or you can simply detach its power cord from the socket.
  3. Allow the system to process everything or reboot for 30 seconds.
  4. Turn the power breaker to the "ON" position again.
  5. Finally, you can now switch back "ON" the thermostat.

How To Determine The Common Carrier Furnace Error Codes?

Any underlying issues in your Carrier furnace come in a series of flashes. This is to inform you that the system needs a quick assessment to prevent damaging its other vital parts.

Proceed to your furnace monitor and record the number of flashes to accurately identify the code. Learning what exactly these codes mean will decide what kind of proper fixes you might want to take.

Use these detailed flashing patterns to determine the fault code in your Carrier furnace:

Flash 1-1

This code will appear once the power controls of 115VAC or 24VAC are shut off. Additionally, status codes in the system will also be deleted within 48 hours of each issue being fixed.

Flash 1-4

It indicates that your system is in an ignition lockout and will auto reset in three hours since the lockout occurs.

Flash 2-1

It alerts you that your furnace gas valve wiring is having trouble if you notice this series of flashes. Anything that involves electrical is very risky, especially if it is beyond your expertise.

Flash 2-4

The problem with this fault code is your auxiliary fuse is open. Inspecting the wire or the fuse is important to avoid short circuits.

Flash 3-3

This time it involves your limit or flame roll-out switch being open. If this switch is left unsettled for more than three minutes, the flashes will then have to adjust to a 1-3 flash pattern.

An error code like this one needs a replacement of your blower motor or capacitor and more.

NOTE: Although, you can easily figure out all of these basic error codes. However, a professional is more suitable to diagnose your furnace unit.

In Conclusion

A Carrier furnace ignition lockout involves one or more defective components. It is always necessary to regularly service its vital parts to keep them working in order with your furnace systems.

Knowing all of our helpful information will surely help you maintain well your Carrier furnace unit. We can now set off with confidence leaving you all of this significant knowledge.

Before you go, check our other related article below!

New Carrier Furnace Noisy – Why And What To Do?

How To Replace A Heat Exchanger In A Carrier Furnace

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