Carrier Infinity Troubleshooting

Carrier Infinity Troubleshooting: Signs to Look Out For

The Infinity system consists of high-end, reliable components, but these components are subject to malfunction like any electrical device. An HVAC system is quite expensive to acquire and install, which is why we’re usually tempted to call a professional each time something goes wrong.

Before calling an HVAC specialist, it’s good to acquire basic troubleshooting skills so that you’re not spending so much money on professional consultations for something you can quickly fix yourself.

We’ll provide you with several pointers that can help you identify sources of any issues emanating from your Carrier Infinity System and ways to troubleshoot and fix the problem!

Troubleshooting Issues During Initial Setup

The installation process for infinity systems is long and, if you’re a first-time installer, the chances are that you’ll mix up some instructions. Here are some issues you may encounter and how to fix them.

Infinity Control Won’t Power Up

If your infinity doesn’t power up, chances are that you didn’t turn the power on after installation.

  • Go to the circuit breaker and switch on the power supply unit and check whether the amber LED is on in the circuit board
  • Access the indoor unit’s circuit board and confirm that the fuse isn’t blown
  • If the power supply isn’t the issue, check your ABCD wire configuration and ensure that all colors match, then check whether the wires are securely attached to the connector
  • Confirm that the connection between the C and D terminals at the connector and Damper Control Module is secure

Infinity Control Won’t Detect the Indoor Unit

This could mean that the ABCD connection between the indoor unit and the infinity control is loose or wrongly connected.

  • Ensure everything is secure and then restart the thermostat
  • If the thermostat still can’t identify the indoor unit, disconnect all connections to the thermostat
  • Start over by first connecting the indoor unit to the thermostat and then adding all accessories and devices consecutively to identify the source of the issue

Infinity Control Won’t Detect the Outdoor Unit

This is most likely a communication issue emanating from the ABCD connector.

  • Check that all configurations are okay
  • Confirm the 24VAC connection between the C and D terminal connector of the outdoor unit

Faulty Thermostat

Have you noticed a change in air temperature control? You might be getting hot and cold temperatures at unexpected times, or the temperature might feel higher than usual. Sometimes you may notice that there’s no air blowing from vents and registers.

Infinity control is the heart of your Infinity System, so that’s the first place you should check first. Changing your thermostat’s setting to “Auto” will help the thermostat automatically vary between heating and cooling depending on your comfort level.

If this isn’t the issue, check whether someone changed the thermostat settings. If so, you can lock your thermostat. Go to the comfort schedule on your infinity control and set your temperature preferences.

Dirty Air Filter

If your air filter is dirty, you may start noticing restricted airflow from your vents and registers, cold and warm spots, and your AC turning on and off prematurely.

Dirty Air Filter

Before blaming the air filter, check that the thermostat settings are okay. Dirty filters are oftentimes results from missing scheduled maintenance visits from your HVAC technician!

Your infinity system consists of both indoor and outdoor units. The indoor unit consists of a furnace or fan coil connected to an air filter that prevents dust and dirt particles from reaching it, and HVAC specialists usually clean and change these to prevent clogging.

Low Refrigerant Level

Refrigerant levels shouldn’t drop fast. Low refrigerant levels could be a sign that there are leaks in the compressor or along the line. Since refrigerants evaporate, you won’t notice it happening. 

If your indoor coils are freezing, this is a leak sign. Refrigerants work by absorbing heat and, if working incorrectly, moisture around the line will begin to freeze.

Frozen Evaporator Coil

A frozen evaporator coil is mainly caused by a dirty or clogged air filter or low refrigerant charge. Signs that you may have a frozen evaporator include:

  • Excessive heating in the house
  • Ice build-up in the outdoor refrigerant line
  • Presence of condensation in the evaporator coil
  • Overflowing condensate drain pan

This isn’t a viable DIY project, and you will have to contact a professional HVAC contractor to fix the issue.

Carrier Thermostat Codes

The good thing about the Infinity system is that its infinity control displays alerts with error codes to help you realize where the problem is. Many error codes touch on the various components of your HVAC system. 

We can’t discuss all of them here, but your owner’s manual should have a list of error codes and what they mean. Error codes make troubleshooting easy because you can quickly identify the cause of a malfunction.

Checkout Mode on Your Infinity Control

Some faults are more accessible to identify than others. Carrier Infinity thermostats have “Checkout Mode,” a useful feature that, when run, comprehensively checks your Infinity System’s health and finds malfunctions for repair. To access this mode, simply follow the steps below.

  • Open your thermostat’s door
  • Locate the “Advanced” button and hold it down for at least 10 seconds
  • “Service menu” should appear
  • Use the scroll button at the bottom of your thermostat to select the “Checkout” option
  • Let the thermostat run diagnostics
  • “Equipment Summary” should provide a list of all connected devices and their status codes
  • Move to “Service Info” and watch the display of fault codes identifying malfunctions in your Infinity System

Resetting Your Thermostat

You need to reset your thermostat in order to remove the error codes after sorting out the malfunctions. To reset a carrier infinity thermostat, please follow the steps below.

  • Hold down the left arrow button until “Accessory Status” comes up
  • Accessory status should show all connected devices and their status’
  • Use the scroll button to choose the accessory you need to reset

Remember that you can’t reset all devices at once, so complete one reset at a time and save your settings!


The carrier infinity system is a massive system with interconnected components, and anything can go wrong. Knowing the basic diagnostic practices will save you the time and money it would cost to hire an HVAC specialist.

Some diagnostic issues require a professional to fix, such as advanced electrical and HVAC problems. However, most problems can be avoided by honoring the maintenance schedules set by your HVAC technician. Instead of waiting until you have to replace your outdoor or indoor units, schedule an appointment with your technician today!