Carrier Error Code P4: Compressor drive fault (Mini-Split)
Carrier error code P4 on a mini-split means: Compressor drive fault. It is also called Carrier diagnostic code P4.
Homeowner? What Carrier code P4 means for you
Call a technician Your ductless mini-split is reporting: Compressor drive fault. The ductless mini-split has locked out or cannot run properly. One reset is fine; if the code comes back, it needs a licensed technician to find the cause.
Safe things you can check yourself
- Check the remote: fresh batteries and the right mode (Cool, Heat or Auto).
- Check the breaker and the outdoor disconnect; both should be ON.
- Open the front cover of the indoor unit and rinse the washable filters if they are dusty; let them dry before putting them back.
- Keep the outdoor unit clear of snow, ice and leaves.
- Try one reset: turn the power off for 30 seconds, then back on. If the code comes back, stop resetting and call a technician.
Call (647) 657-2977Book a service call
Licensed technicians serving Vaughan, Toronto and the GTA.
What does Carrier error code P4 mean?
Compressor drive problem; same checks as the IPM fault. Shown on the 48K high heat model.
Applies to: DLCMHBH48EAK (48K high heat) only
Carrier models that use code P4
DLCMHBH24CAKDLCMHBH30DAKDLCMHBH36DAKDLCMHBH48EAKDLCMRBH18BAKDLCMRBH36DAKDLCMRBH48EAK
Other Carrier Mini-Split codes
All Carrier Mini-Split error codes →
Carrier code P4: homeowner questions
What does Carrier code P4 mean?
Compressor drive fault. Compressor drive problem; same checks as the IPM fault. Shown on the 48K high heat model.
Is it safe to keep using my ductless mini-split with code P4?
It depends on the cause. The ductless mini-split has locked out or cannot run properly. One reset is fine; if the code comes back, it needs a licensed technician to find the cause.
Can I reset Carrier code P4 myself?
You can try one reset (power off for 30 seconds, then on). If Carrier code P4 comes back, the cause is still there and a licensed technician should check it.
Who can fix Carrier code P4 near me?
Aurora Star Tech Inc. repairs Carrier ductless mini-splits in Vaughan, Toronto and across the GTA. Call (647) 657-2977 or book a service call online.
Homeowner help: AC Running But Not Cooling: What to Check · Heat Pump Not Heating or Blowing Cold Air
Troubleshooting guides
- Indoor unit leaking water All brands · Mini-Split
- Poor capacity / high head All brands · Mini-Split
- Water leaking All brands · Mini-Split
- Discharge the inverter capacitors before service Carrier · Mini-Split
- Display shows a strange code or does not answer the remote - DLFSHB indoor Carrier · Mini-Split
- Multi-zone: one room heats, another will not cool - DLC multi-zone Carrier · Mini-Split
- Read live data with the outdoor check button (SW1) Carrier · Mini-Split
- Run the automatic wiring / piping correction Carrier · Mini-Split
Source: DLCMRBH/DLCMHBH Multi-Zone Outdoor Service Manual (sold as Midea, Carrier and Viessmann Vitocal 200-S; Viessmann doc 6225551-03, 12/2024), Table 24 Outdoor Unit Error Display (48 High Heat only) p.27; diagnosis p.68. Written in our own words as a summary; always check the original manual.
General guidance for qualified technicians. The manufacturer's installation and service manual and local codes always take priority. Aurora Star Tech is not affiliated with, endorsed by or sponsored by any equipment manufacturer; brand and model names are used only to identify equipment and belong to their owners.