What does Samsung Mini Split Not Heating - Causes & Fix mean?

Most likely the system is in the wrong mode or the set temperature is too low. Switch to Heat mode and raise the setpoint above room temperature.

How do I fix Samsung Mini Split Not Heating - Causes & Fix?

Work through the step-by-step fix below. Start with the quick reset and the most common cause, then check the specific part this guide points to. Most fixes need only basic hand tools and the right replacement part.

Can I keep using my Samsung appliance with this error showing?

Usually not. Samsung appliances show this error when a part or safety circuit is out of range, so running it can stop the cycle or make the problem worse. Diagnose and clear the error before normal use.

What part is most commonly replaced for Samsung Mini Split Not Heating - Causes & Fix?

The parts that most often fix Samsung Mini Split Not Heating - Causes & Fix are listed in the parts section of this guide. Match the part to your exact model and serial number before you buy.

Is Samsung Mini Split Not Heating - Causes & Fix a DIY repair or do I need a technician?

Many fixes are DIY-friendly with basic tools, such as door switches, drain pumps, water inlet valves, thermostats, heating elements, and filters. Sealed-system, refrigerant, gas, or high-voltage work should go to a licensed technician for safety.

Samsung Mini Split Not Heating - Causes & Fix

Samsung Mini Split Not Heating — What’s Happening

When your Samsung mini split won’t heat, the indoor unit is either not producing warm air or is blowing cold or room-temperature air. The outdoor compressor may not be running at all, or it may run but the system still doesn’t warm the space. In many cases the remote or indoor unit displays a fault code like Lo (low-temperature lockout), E1 or 22 (heat exchanger sensor failure), or E123 (indoor outlet sensor error).

The most common root causes are simple: the system is set to Cool or Fan mode instead of Heat, the setpoint is at or below room temperature, or the indoor filter and coil are blocked with dust. Less often, refrigerant has leaked out, the outdoor unit is iced over or blocked, or a temperature sensor on the indoor coil has failed. Samsung mini splits rely heavily on accurate sensor readings to control heating cycles, so sensor faults will lock out the compressor even when everything else is mechanically sound.

Jump to Fix

Most Likely Causes

Wrong mode or setpoint on the remote The system is in Cool, Dry, or Fan mode instead of Heat, or the temperature is set below the current room temperature, so the unit never calls for heating.
Dirty indoor air filter or blocked coil Dust and debris restrict airflow across the indoor heat exchanger, causing the coil to overheat and trip a safety limit or preventing heat transfer into the room.
Low-temperature lockout (Lo code) The outdoor temperature is below the system’s configured cold-weather startup threshold, locking out compressor operation until the setting is adjusted or outdoor conditions improve.
Refrigerant leak or undercharge A leak in the refrigerant circuit or an installation charge error leaves too little refrigerant to absorb and move heat, so the system runs but produces no warmth.
Failed indoor heat exchanger temperature sensor The thermistor that monitors coil temperature (often a 10 kΩ type) has failed open or shorted, triggering fault codes E1, 22, or E123 and stopping heat operation.
Outdoor unit iced or airflow blocked Ice buildup on the outdoor coil or obstructions like snow, leaves, or tight clearances prevent the outdoor unit from pulling heat from the air, shutting down the compressor on protection.
Compressor or outdoor fan failure The compressor does not start when heating is called for, or the outdoor fan motor has failed, preventing heat exchange at the condenser and stopping heating entirely.

How to Diagnose and Fix

Verify the remote is set to Heat mode and the setpoint is at least 5°F above the current room temperature, then wait two minutes to see if the compressor starts.
Power off the system at the breaker or disconnect for 60 seconds, then restore power to clear any temporary control glitches.
Remove and inspect the indoor air filter; clean or replace it if dust is visible, and visually check the indoor coil for blockage.
Go outside and inspect the outdoor unit for ice, snow, leaves, or obstructions within two feet of the unit; clear any debris and check that the fan spins freely by hand (power off).
Turn the system back to Heat mode and listen at the outdoor unit; confirm the compressor hums or runs and the fan spins when heating is called for.
Check the indoor unit display or remote for a fault code; write down codes like Lo, E1, 22, or E123 and refer to your owner’s manual or Samsung support for the specific meaning.
If a sensor code is displayed (E1, 22, E123), locate the sensor connector on the indoor coil (near the refrigerant lines) and measure resistance with a multimeter; an open circuit (infinite ohms) or dead short (zero ohms) confirms sensor failure.
If the outdoor unit runs but no heat is produced and no codes are shown, check for frost or ice on the outdoor coil or indoor coil; this typically indicates refrigerant loss and requires professional recovery, leak repair, evacuation, and recharge.

Parts You Might Need

Part	Notes
Indoor heat exchanger temperature sensor (thermistor)	Amazon \| Typically a 10 kΩ thermistor, used for E1, 22, or E123 faults.
Indoor air filter (washable or replacement)	Amazon \| Model-specific; clean monthly or replace every three months.
Indoor fan motor or capacitor	Amazon \| Required if the indoor fan fails to spin and triggers a fan-fault code.

If your appliance also shows a code on the display, these match this problem:

When to Call a Pro

Call a qualified HVAC technician if you see a sensor fault code (E1, 22, E123) and are not comfortable testing or replacing thermistors, if the outdoor compressor does not start after verifying mode and power, or if the system runs but produces no heat and you suspect refrigerant loss. Refrigerant work (leak detection, recovery, evacuation, and recharge) requires EPA certification and specialized gauges. Also call a pro if the outdoor unit is heavily iced and does not clear after an hour of fan-only operation, or if the control board shows communication or EEPROM errors that you cannot clear by power cycling.