Icon
Reliable Heating and Cooling Solutions – Quality Service, Fair Prices, Guaranteed Satisfaction!

Follow Us On:

Logo
Contact US!

Gree MULTI18HP230V1CO Error Codes

Updated · by Aurora Star Tech Inc.

Gree MULTI18HP230V1CO error codes and diagnostic codes. The MULTI18HP230V1CO is a Gree heat pump in the Gree Multi21+ series.

Homeowner with a heat pump problem? Call (647) 657-2977 or book a service call — licensed technicians across Vaughan and the GTA.

Gree MULTI18HP230V1CO error codes list

CodeMeaningSeverity
b5Liquid line (valve) temperature sensor open or shortedMedium
b7Gas line (valve) temperature sensor open or shortedMedium
C5Jumper (capacity) cap missing or badMedium
ddWiring/EEV check running (status)Low
dnWrong interconnect wiring or EEV faultMedium
E1High pressure protectionHigh
E3Low pressure protectionHigh
E4Compressor discharge temperature too highHigh
E5Overcurrent protection (whole unit)High
E6Indoor/outdoor communication faultHigh
E7Mode conflict between indoor units (status)Low
E8High temperature / overload protectionMedium
EEEEPROM / memory chip faultHigh
F0Low refrigerant / refrigerant blocked protectionHigh
F1Indoor room air sensor open or shortedMedium
F2Indoor coil sensor open or shortedMedium
F3Outdoor ambient sensor open or shortedMedium
F4Outdoor coil (condenser middle) sensor open or shortedMedium
F5Compressor discharge sensor open or shortedMedium
FoRefrigerant recovery (pump-down) modeLow
H1Defrost or oil return (status)Low
H3Compressor overload protectionHigh
H5IPM (inverter module) protectionHigh
H6Indoor fan motor not running / no feedbackHigh
H7Compressor lost synchronismHigh
HCPFC protectionHigh
L3Outdoor DC fan motor faultHigh
LCCompressor failed to startHigh
LdCompressor phase lossHigh
LPIndoor and outdoor units do not matchMedium
P5Compressor phase overcurrentHigh
P7Inverter module temperature sensor faultMedium
P8Inverter module overheatedHigh
PHDC bus voltage too highHigh
PLDC bus voltage too lowHigh
PUDC bus capacitor charging faultHigh
U1Compressor phase current sensing faultHigh
U7Reversing (4-way) valve faultHigh
U8Indoor zero-crossing signal faultMedium

Troubleshooting the MULTI18HP230V1CO

All Gree Heat Pump error codes →

Homeowner help: AC Running But Not Cooling: What to Check · Heat Pump Not Heating or Blowing Cold Air

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.

© 2026 Aurora Star Tech Inc. All rights reserved. This page may not be copied, republished or used to train other systems without written permission.

Emergency HVAC Service

647-657-2977