314Have a focus inspection on the following area:
a. Each pipe union joint and valve connection.
b. All hose, especially near the pipe union.
c. Compressor shaft seal, front and rear cover, gasket, oil fill plug.
d. Area on the surface of the condenser and evaporator that is scratched, bruised or damaged.
e. Expansion valve inlet and outlet connection and temperature sensor element and the welding position.
3. Check the Refrigerant
Observing from the sight glass, you may understand the refrigerant status and analyze the possible faults:
4. Check Other Parts
Other parts needed to be checked and their check points:Conditions obse rvedP ossible proble ms
Cle ar, no a ir bubble , A/C e mits c ool wind Re frige ra tion system is normal
Cle ar, no a ir bubble , A/C e mits warm wind Re frige ra nt le a ke d, the re is le aka ge in the syste m
Occ a tiona l a ir bubble . Expa nsion va lve is froste d There is wa te r mixe d in the re frigeration syste m
Occational air bubble. Insufficient refrigerant or air mixed in the system
Cle ar, the re is oil stripe on the gla ss Outle t is not c old, no refrige ra nt
Foamy and turbid Excessive freezing oilChecked PartCheck Points
The re sha ll be no dirt and rust on the radiator tha t hinde r the he at
exchange;
The ra dia tor surfa ce ha s no da mage , fissure a nd hidde n trouble tha t ma y
cause refrigerant leakage.
Elec tromagne tic Clutc hClutc h ope ration is norma l. Whe n switche d on, the c ompre ssor sha ll
operate, clutch can not slip.
Compre ssor Be lt Be lt te nsion of 250N is normal, belt is not broke n and dama ged.
WireThe electromagnetic clutch and blower power cable shall be not damaged
and overheated; the connection shall be reliable, and the protective
gromme t through the me tal plate sha ll be ke pt good a nd without da ma ge .
HoseRefrigerant hose and condenser pipe shall be secured and shall not be
dama ged by a pproac hing the othe r ove rhe ate d pa rts, moving pa rts a nd
sha rp parts. Eva pora tor Conde nse r
317Table 2. Problem Cause and Troubleshooting of No Heating:Area Problem Cause TroubleshootingH
eat
i
ng
Sy
st
emWater temperature sensor damaged Repair or replac e
Blow er motor does not rotate Repair or replac e
Fan s peed adjus tment sw itc h damaged Replac e
Output air temperature adjustment sw itc h damaged Replac eH
eat
i
ng
Sy
st
emTable 3. Problem Cause and Troubleshooting of Noise:Problem Cause Troubleshooting
Drive belt loose or w orn Replac e the drive belt
Cooling electric fan touc hes other parts Service and eliminate the impac t
Blow er motor mec hanic al fric tion Servic e and fill the oil
N o o il o n t h e m o t o r b e a r in g , d r y f r ic t io n F ill t h e g r e a s e o r r e p la c e t h e b e a r in g
Low battery voltage Charge the battery Ar e a
