Gree                GMV6 DC Inverter VRF Units Service Manual 
 
"U8" Ab no rmal P ipes of the  
In do or Unit
Po wer on  th e u nits base d 
on  th e capa city an d  nu mber of  indoor u nits 
en ab led  previou sly in t he  case  of  pr ot ection  sta te. Af ter  
con firming  th at  the  EX V co il o f t he indo or  u nit is conn ecte d 
pro per ly, po wer of f th e u nit. The n, po wer 
on to reset the unit and check the 
rese tting act ion
No
Replace the  expan sion valve coil 
or main bo ard
Whet her t he  pipe s are clog ge d a s a  re sult o f 
weldin g f ailur e? W het her t he  filter is d irty and  whe the r 
the electronic expansion valve is stuck?
Yes
 
 
2.144 "U9" Abnormal Pipes of Outdoor Unit 
Fault display: main board of outdoor unit, wired controller of indoor unit and receiver of indoor unit 
display   
Fault diagnosis: 
During commissioning process, check the pressure of the unit to determine whether the pipes of the 
outdoor unit are blocked. Any abnormal parameters found would indicate that the unit has the fault. 
Possible causes: 
■ The electronic expansion valve operates improperly; 
■ The outdoor unit's pipes are blocked. 
Troubleshooting: 
"U9" Ab no rmal P ipes of Outd oo r 
Unit
Power on the units 
based on the capacity an d number of 
indoor u nits enabled previously in the case of 
protection state. After  confirm ing th at the EXV coil of the indoor 
unit is connected properly, powe r off the unit. Th en, 
powe r on to reset the unit and check 
the reset ting action
No
Replace the  expan sion valve coil 
or main bo ard
Whet her t he  pipe s are clog ge d a s a  re sult 
of  welding fa ilure? Whet he r t he  filter is d irty and  
whether the electronic expansion valve is stuck?
Yes