My Mini Split Is Not Cooling or Heating Properly

If your Senville mini split system isn’t cooling or heating as expected, it can usually be traced to a few common causes. This article will help you troubleshoot and identify the issue before calling for service.

Quick Checklist Before You Begin

• Is the unit turned on?
• Is the remote in the correct mode (Cool/Heat)?
• Are all doors and windows closed in the room?
• Is there airflow coming from the indoor unit?

If all of the above seem fine, move on to the detailed steps below.

1. Check the Mode and Temperature Settings

• Make sure the unit is in the correct mode:
  • Cool mode for cooling (snowflake icon)
  • Heat mode for heating (sun icon)
• Set the temperature at least 3–5°F above or below the current room temp, depending on mode.
• If the unit is in “Fan” or “Dry” mode, it will not heat or cool.

✅ Tip: Try switching to “Auto” or directly to “Cool”/“Heat” for faster temperature adjustment.

2. Clean or Replace the Air Filter

• A clogged filter restricts airflow, making it hard to heat or cool the room.
• Open the front panel of the indoor unit and remove the filter.
• Rinse it with lukewarm water and let it dry completely before reinserting.

Clean your filter every 2–4 weeks for optimal performance.

3. Check for Ice Buildup (Cooling Only)

• If you notice frost or ice on the indoor unit, it could be caused by:
  • Low refrigerant
  • Dirty filters or coils
  • Poor airflow
• Turn off the unit and let it thaw completely before restarting.

See: Why Is My Indoor Unit Freezing?

4. Inspect Airflow and Fan Speed

• Make sure nothing is blocking the air intake or outlet.
• Check the fan setting on your remote — increase the fan speed if it's set to low or auto.
• If airflow seems weak or uneven, the blower fan may need cleaning or service.

5. Outdoor Temperature Considerations (Heating Only)

• In very cold weather (below -5°C / 23°F), heat pumps may struggle.
• Your unit may enter a defrost mode, temporarily stopping warm air.
• This is normal — allow a few minutes and check again.

6. Check for Error Codes or Flashing Lights

• If your unit displays an error code (e.g., E5, P1, F1), it may be protecting itself from a fault.
• Refer to the error code guide here: Senville Error Codes & What They Mean

7. Low Refrigerant (Requires Technician)

• If your unit runs but doesn’t cool or heat at all, it could be low on refrigerant.
• This is not a DIY fix and requires a certified HVAC technician.

8. Try Resetting the System

1. Turn off the system at the remote.
2. Unplug the power (or turn off the breaker) for 5 minutes.
3. Turn it back on and reprogram your settings.

Still Need Help?

If you’ve gone through the steps above and your unit still isn’t working properly, we’re here to help.