inner 
hexagonspanner
close
open
liquid valve
gas valve
Use Vacuum Pump 
1. Remove  the  valve caps on the liquid  valve  and  gas valve 
and the nut of refrigerant charging vent. 
2. Connect the charging hose of piezometer to the refrigerant 
charging vent of gas valve and then connect the other charging 
hose to the vacuum pump. 
3. Open the piezometer completely and operate for 10-15min 
to check if the pressure of piezometer remains in -0.1MPa.
4. Close the vacuum pump and maintain this status for 1-2min 
to check if the pressure of piezometer remains in  -0.1MPa. If 
the pressure decreases, there may be leakage.
5. Remove the piezometer, open the valve core of liquid valve 
and gas valve completely with inner hexagon spanner. 
6. Tighten the screw  caps  of valves and refrigerant  charging 
vent. (As show in Fig.26)
Leakage Detection 
1. With leakage detector
:
 
Check if there is leakage with leakage    detector.
2. With soap water:
If leakage detector is not available, please use soap water for 
leakage detection. Apply soap water at the suspected position
and keep the soap water  for more than  3min. If there are  air 
bubbles coming out of this position, there's a leakage.
Fig.26
8.7 Vacuum Pumping and Leak Detection
1. Check After Installation
Check according  to  the  following requirement  after  finishing 
installation.
2. Test Operation
(1) Preparation of test operation
The client approves the air conditioner installation.
Specify the important notes for air conditioner to the client.
(2) Method of test operation
Put through the power, press  ON/OFF  button  on the remote 
controller to start operation.Press MODE button to select AUTO, 
COOL, DRY, FAN and HEAT to check whether the operation is 
normal or not.If the ambient temperature is lower than 16
℃
, 
the air conditioner can’t start cooling.
8.8 Check after Installation and Test 
Operation
NO. Items to be checked Possible malfunction
1
Has the unit been 
installed rmly?
The unit may drop, shake or 
emit noise.
2
Have you done the 
refrigerant leakage test?
It may cause insufcient cooling 
(heating) capacity.
3
Is heat insulation of 
pipeline sufcient?
It may cause condensation and 
water dripping.
4 Is water drained well?
It may cause condensation and 
water dripping.
5
Is the voltage of power 
supply according to the 
voltage marked on the 
nameplate?
It may cause malfunction or 
damage the parts.
6
Is electric wiring and 
pipeline installed 
correctly?
It may cause malfunction or 
damage the parts.
7
Is the unit grounded 
securely?
It may cause electric leakage.
8
Does the power cord 
follow the specication?
It may cause malfunction or 
damage the parts.
9
Is there any obstruction 
in air inlet and air outlet?
It may cause insufcient cooling 
(heating) capacity.
10
The dust and 
sundries caused 
during installation are 
removed?
It may cause malfunction or 
damaging the parts.
11
The gas valve and liquid 
valve of connection pipe 
are open completely?
It may cause insufcient cooling 
(heating) capacity.
12
Is the inlet and outlet 
of piping hole been 
covered?
It may cause insufcient cooling
(heating) capacity or waster 
eletricity.