Carrier mini split troubleshooting

HVAC Logo IconBy HVAC.comAugust 1, 2023

If your mini split is acting strange, give these instructions a try. Your unit may just need a good dusting or a fresh air filter. These DIY Carrier mini split troubleshooting tips may save you the hassle and expense of a service visit.

Carrier mini split is inconsistently running

This problem may signal poor communication between the indoor unit and the outdoor compressor.

Try resetting the mini split by turning the power off and on. If this doesn’t help, you may need an HVAC technician to examine the wiring between the indoor and outdoor components.

Carrier mini split’s outdoor unit turns on, but indoor unit does not

Does the indoor unit have power? Check your electrical box to ensure a breaker didn’t trip or a fuse blow. Make sure the switch it’s connected to is on. If that doesn’t do the trick, consult a technician.

Alternatively, a jammed condenser coil may cause this to happen. An HVAC contractor should handle that repair.

Carrier mini split cannot maintain temperature

Make sure the indoor components are clean. Your sensors may not be able to read the temperature correctly. Open the cabinet and dust the inside with canned air or a soft rag. Change your air filters if it’s time to do so.

Several factors can cause this issue – from a refrigerant leak to a clogged drain line. Consult a technician if dusting and freshening the filter don’t solve the problem.

Carrier mini split is making loud or unusual noises

A rattling sound may indicate something is loose and needs tightening. Check your units for loose bolts and screws.

Other noises like buzzing, screeching, or hissing require the attention of a professional. If the noise isn’t consistent, record it on your phone to play for your tech.

Carrier mini split troubleshooting: model lookup

Carrier’s website and the manual that came with your system feature additional Carrier mini split troubleshooting information related to your specific model.

We’ve linked to the product documentation for Carrier’s mini split line below.

Carrier mini split troubleshooting documentation

38MAR38MARB38MBR
38MBRB38MGR38MHRBC
38MHRBQ38MPRA40MAQ
40MBAA40MBCQ40MBDQ
40MBFQ40MHHC40MHHQ
40MPHARAVATRAVBT
RAVCTRAVKRRAVUT

Don’t see your model listed? Look it up here.

When to call an HVAC professional

Contact an HVAC technician when you’ve tried the Carrier mini split troubleshooting tips above and still can’t solve the problem.