Hisense RD-31WC4S Service Manual

Refrigerator

Service manual

NO FROST

MODEL:RD-31WC4S* (BCD-228W)

NOTE: product specifications are subject to change.

Contents

Warnings and precautions for safety ............................................................................................................................ 2

Parts Description .......................................................................................................................................................... 3

Cooling diagram .......................................................................................................................................................... 5

Checking the Compressor ............................................................................................................................................ 7

Checking the Heater .................................................................................................................................................... 8

Checking the timer ....................................................................................................................................................... 8

Checking the defrost fuse .......................................................................................................................................... 10

Checking the defrost thermostat ................................................................................................................................ 10

◆The instruction of replacing the thermostat. ........................................................................................................... 11

◆ The instruction of replacing refrigerator Light bulb. ........................................................................................... 12

◆The instruction of replacing the timer .................................................................................................................... 13

◆ The instruction of of replacing fan motor. ........................................................................................................... 13

◆The instruction of replacing evaporator temperature temperature fuse and heater ................................................ 15

◆ The instruction of replacing Door switch. ........................................................................................................... 15

◆ The instruction of replacing PTC Starting relay and Overload protector. ........................................................... 16

Water Dispenser ......................................................................................................................................................... 17

Troubleshooting ......................................................................................................................................................... 19

◆The common problem judgement method ............................................................................................................. 19

◆The solution for the common problem. ................................................................................................................. 20

Note: .......................................................................................................................................................................... 22

Warnings and precautions for safety

Please observe the following safety precautions in order to use safely and correctly the refrigerator
and to prevent accident and danger during repair.

1. Be care of an electric shock. Disconnect power cord from wall outlet and wait for more than
three minutes before replacing PCB parts.
Shut off the power whenever replacing and repairing electric components.

2. When connecting power cord, please wait for more than five minutes after power cord was
disconnected from the wall outlet.

3. Please check if the power plug is pressed down by the refrigerator against the wall.
If the power plug was damaged, it may cause fire or electric shock.

4. If the wall outlet is over loaded, it may cause fire.
Please use its own individual electrical outlet for the refrigerator.

5. Please make sure the outlet is properly earthed, particularly in wet or damp area.

6. Use standard electrical components when replacing them.

7. Make sure the hook is correctly engaged.
Remove dust and foreign materials from the housing and connecting parts.

8. Do not fray, damage, machine, heavily bend, pull out or twist the power cord.

9. Please check the evidence of moisture intrusion in the electrical components.
Replace the parts or mask it with insulation tapes if moisture intrusion was confirmed.

10. Do not touch the icemaker with hands or tools to confirm the operation of geared motor.

11. Do not let the customers repair, disassemble and reconstruct the refrigerator for themselves.
It may cause accident, electric shock, or fire.

12. Do not store flammable materials such as ether, benzene, alcohol, chemicals, gas, or
medicine in the refrigerator.

13. Do not put flower vase, cup, cosmetics, chemicals, etc., or container with full of water
on the top of the refrigerator.

14. Do not put glass bottles with full of water into the freezer.
The contents shall freeze and break the glass bottles.

15. When you scrap the refrigerator, please disconnect the door gasket first and scrap it

Parts Description

Circuit diagrams and Basic parameters

Basic parameters

Voltage / frequency

220-240V~ 50HZ

Net capacity l 228L

Net capacity fridge compartmen (Fridge/Chill) l 147L

Net capacity freezer compartment

l 81L

Energy efficiency class

A+

Climate class (SN=10~32°C, N=16~32°C,
ST=16~38°C, T=16~43°C) N、ST、T

Freezer compartment star rating 4 Star

Energy consumption / year kWh/year 266

Energy consumption (ISIRI 4853-2) per 24 h kWh/24 h 0.728

Freezing capacity / 24 hours kg/24 h 4

Compressor （W） 220V,≦73.3W×115%

PTC starter （V/Ω） 220V ,15±20%Ω

Overload protector

(Turn off/Turn on) °

C 120±5°C/ 61±9°C

Heater （V/W/Ω）

220V,150W±10%

322Ω±10%

Timer （V/W/h） 220V!≤0.5W!10min!12h

Light bulb （V/W） 220V，15W

fan motor （V/W） 220V，2W

Max noise level dB(A) ≤42

Kind of coolant / Charge (R134a/R600a) /
grammes R / g R600a/35

Net weight kg 57.5

Gross weight kg 62.5

W x D x H (appearance) mm 550×572×1750

W x D x H (packaging) mm 583×598×1823

Cooling diagram

Checking the Thermo stat

Use a multi-meter to test the resistance between L & C when the thermostat is at normal position

such as: “ 1, 2, .. 7” :
If there shows “000”then the thermostat is OK
If there shows anything but “000”then the thermostat is always at OFF Position and compressor
will not start ever.

Use a multi-meter to test the resistance between L & H and C&H when the thermostat is at shut
position such as “0”:
If there shows no response then the thermostat is OK
If there shows anything (have response) then the thermostat is always at ON Position and the
compressor will keep on working and will not stop ever.
Put the sensor pipe of the thermostat in the freezer compartment like the below pic shows.
Put the thermostat at Max 7 position and let it keep this position for 20 minutes.
Turn the knob from 7 to 1 slowly
If you can feel a stop signal like kind of noise of “da”the thermostat is ok.
If there is no stop signal then the thermostat is always at ON position and the compressor will keep
on working and will not stop.

Checking the Compressor

Use a multi-meter to test the resistance between C & S, M&S and M&C :
Normal range of C&M : About 10-30Ω
Normal range of C&S : About 10-32Ω
Normal range of S&M : About 20-60Ω
If the test result is not in this range then it means the inner coil has some problem and the
compressor can not work properly.

Compressor Protector test ——
Use a multi-meter to test the resistance between the two end as the pic show :
If there show 000 or almost 0 then it is OK.
If there is no response then it is broken.

Compressor PTC starter test ——
Use a multi-meter to test the resistance between the two end as the pic show :
If there show the number is between About 9-25Ω then it is OK.

If there show 000 or no response then it is broken.

Checking the Heater

If defrost system failure，check the heater and the temperature fuse as well as wires.
Measuring temperature fuse and heater resistance about 361Ω then it is OK.( Blue and Y ellow)

Checking the timer

Timer is an importance control component for air defrost refrigerator’s defrost system. The common
problems as following: bad cooling, evaporator don’t defrost or defrost incomplete. It’s working
principle as following picture。

1 means power port 2 means defrost port 3 means common port 4 means compressor port
1、1-3 is the timer coil running connect wire port.
2、3-4 is compressor running connect wire port
3、3-2 is defrost heater working connect wire port
Checking method as following picture:

As picture, set the timer to the compressor running, use the multimeter measure the foots of 3 and 4,
if the value of resistance is 0000, it means normal.
Because there is capacitance resistance in the timer’s internal circuit, so when you use the multimeter
to measure the coil running port, it will can’t measure the value. If you want to measure the coil
running is normal or not, you can power on (220V) to foot 1 and 3 of timer, then put the timer near to
your ear，if you can hear the running sound, it means normal, if no hearing the running sound, it
means anormal.
NOTE: When measure the using the power supply to measure please pay attention to the timer’s
working voltage.

Picture 1 Picture 2

As picture 1, adjusting knob as the picture it mean into the defrost, other area is compressor working.
As picture 2, adjusting the timer to defrost working, then use the multimeter measure the foots of 3
and 2, if the value of resistance is 0000, it means normal.

Checking the defrost fuse

Fuse is a high t emperature prot ector of defros t system, when d efrosting, if it feel the tem perature is
more than 73℃, it will cut off the defrost heater, stopping defrost, so that it can protect the parts. The
common problems are evaporator defrost incomplete:
Checking method as following:

Picture 1 Picture 2

As picture 1，it is the defrost fuse.
As picture 2 , using the multimeter measure two foots of fuse, if the value of resistance is 0000, it
means normal.

Checking the defrost thermostat

The thermostat is a l ow temperat ure p rotecto r of d efrost s ystem , when i t feel t he temp eratur e is m ore
than 6℃, it will cut off the timer, when it feel the temperature is less than -7℃, it will start switching
on the timer and let it working. The common problem is the evaporator don’t defrost:
Checking method as following:

Picture 1 Picture 2
The picture 1 is defrost thermostat
As picture 2, using the multimeter measure two foots of defrost temperature sensor, it should be open
circuited. If you want to judge the defrost temperature sensor is good or bad, you can put the defrost

temperature sensor into a refrigerator’s freezer (The temperature is below -18℃ ), after 10-20

mins, measuring two foots of defrost temperature sensor, if the value of resistance is 0000, it means
normal.

The guide for Disassembly Common parts of Refrigerator.

◆The instruction of replacing the thermostat.

1. Use a screwdriver to

remove the thermostat

box screws

2. Take out the

thermostat box

3. Tidy up the electrical

wires.

4. Remove the

thermostat fixing nut

5. Take out the

thermostat.

◆ The instruction of replacing refrigerator Light bul b.

Light bulb data:

220-240 V,max.15W.

Unplug the mains plug

1.To change the light

bulb, undo the screw.

2.Press the light bulb

cover and slide

it backwards.

3.Change the defective

light bulb.

4.Refit the light bulb

cover and the screw.

5.Put the refrigerator

back into operat ion.

◆The instruction of replacing the timer

1. The location of the

time.

2. Remove the screws

of Timer cover.

3. Take out timer and

unplug the connect ing

wire.

◆ The instruction of of replacing fan motor.

1. Remove the air duct

cover plate screw

2. Remove the screw

cover

3. Unscrew two screws

of the wind channel

part in freezer

chamber.

4. Removing wires.

5. Remove the wind

channel part in freezer

chamber.

6. Take out the fan
motor.

◆The instruction of replacing evaporator temperature temperature fuse

and heater

1. Take out the
evaporator
temperature fuse

2. Take out the
defrost temperature
sensor

3. Take out the
replacing heater

◆ The instruction of replacing Door switch.

1. Use a screwdriver to

pry snap.

2. Take out of the door

switch.

◆ The instruction of replacing PTC Starting relay and Overload protector.

1. The locat ion of the

PTC Starting relay and

Overload protector.

2. Take down Spring

Tap and Cover.

3. Disconnect the

connect ing wire of the

PTC Starting relay and

Overload protector.

Water Dispenser

Troubleshooting

◆The common problem judgement method

Problem Cause

Refrigerator can’t start

1.1 Is the power cord connect ing well？

1.2 Is the power voltage too low？

1.3 Is the sensor irrational setting?

1.4 Is the ambient temperature too low?

1.5 Is the circuit on power?

1.6 Is there some default in compressor

1.7 Is the refrigerat ion system blocked by ice or dirty, please stop the unit and restart

after 10 minutes to see if the compressor can start.

Weak cooling effects

2.1 Is there any heat source around the refrigerator?

2.2 Is there enough space around the refrigerator for reject ion of heat?

2.3 Is the sett ing of the temperature appropriate?

2.4 Is there too much food or overheat ing food in it?

2.5 Does there open the door frequently?

2.6 Is the door completely closed?

2.7 Does the gasket destroyed or distort?

2.8 Does the gas leak?

The unit can not stop

running

3.1 Is there any heat source around the refrigerator?

3.2 Is there enough space around the refrigerator for reject ion of heat?

3.3 Is the setting of the temperature appropriate?

3.4 Is there too much food or overheat ing food in it?

3.5 Does there open the door frequently?

3.6 Is the door completely closed?

3.7 Does the gasket destroyed or distort?

3.8 Is the thermostat good operation?

3.9 Does the gas leak?

Ice up in the freezing

chamber

4.1 Is the sett ing of the temperature appropriate?

4.2 Is there multi-moisture food and too close to the back wall of the refrigerator?

4.3 Is the ambient temperature too low?

4.4 Is the electric parts on good condit ion, specially the thermostat which will cause the

unit non-stopping .

Abnormal noise

5.1 Is the refrigerator stably placed?

5.2 Does the refrigerator bump other objects?

5.3 Whether the internal accessory of the refrigerator is in the right place.

5.4 Whether the water plate of compressor is fall from the unit.

5.5 Does the tube of the refrigeration system bump each other?

5.6 The noise sound likes Water flow inside the refrigerator ,in fact ,it is normal, which is

caused both when refrigerator start and shut-down; in addit ion, frost-

dissolving

causes this sound, too, which is a normal phenomenon.

5.7 There will be a cracking sound in the cabinet ,when the cabinet or cabinet accessory

contract ing or expanding, this sound will be made, which is normal.

5.8 The motor operat ion sound in the compressor is appears to be louder at night or

begin start ing. which is a normal phenomenon; also the uneven placing would lead to

too much running noise.

There is a peculiar

smell in the units

6.1 Is the food with special smell sealed t ight?

6.2 Does it have long time storing food or degenerated food?

6.3 Whether the internal cabinet needs cleaning.

the forefront or the

middle cabinet heats

7.1 As fridge Anti-condensat ion tube is placed here and caused the above phenomenon,

which is normal.

Refrigerator’s two

sides or the back heat

8.1 As condensat ion tub

e is placed here and caused the above phenomenon, which is

normal.

the cabinet surface

condensat ion

9.1 Air humidity is too large.

◆The solution for the common problem.

1.Cooling is not enough good

(Many reasons might cause that cooling not enough good, as blow :)

Reason Analysis Solutions

1) Leakage of Gas

If some gas leaked unit will work not well.

Phenomenon of failure:

a. lower pressure of liquid cycle system

b. high temperature of copper tube of

discharging gas, hand feels very hot.

C. much noise, sounds like “ZZZZZ”, comes

from outlet of capillary.

d. the temperature fell down very slowly.

First f ind out the point of leaking on

tube, and then sealed it, vacuuming

it, finally recharge with Gas.

Note:

If you find oil on somewhere, it is

possible that leakage point is there.

2) The quant ity of Gas is

too much

If too much Gas was charged into the cycle

system, the extra gas will occupy some space

of evaporator, so that the area of heat

exchange becomes less, unit will work not well.

Phenomenon of failure:

a, higher pressure of liquid cycle system than

norm.

b, higher temperature of condenser.

c, larger electric current of compressor

d, there maybe ice on the suction tube.

e, when gas is too much, some gas liquid might

goes back into compressor, compressor will be

damaged by liquid.

First stop unit for several minutes,

and then open charging tube,

discharge all of gas. Change a new

filter, and then recharge gas, finally

sealed the system.

3) There is air in the

liquid cycle system

The air in system will cause lower efficiency of

cooling.

Phenomenon of failure:

a, higher pressure of liquid cycle system than

norm, but the pressure is not over the limit.

First stop unit for several minutes,

and then open

charging tube,

discharge all of gas. Change a new

filter, and then recharge gas, finally

sealed the system.

b, higher temperature of discharging tube.

C, much noise

4)Low working

efficiency of

compressor

General when a compressor works for many

years, some parts of compressor were wear, so

that compressor disc

harge less gas out, unit

does not work strongly.

Phenomenon of failure:

a, lower pressure of discharging, check the

pressure of system with pressure meter to see

if it is normal.

b, higher temperature of compressor surface.

C, cut off the discharging tube, to see if you can

block the gas coming out of the tube when

compressor is working.

Change a new compressor.

5

) There is something

that blocked the liquid

cycle system

Some t ime there is something blocked the

filter of liquid cycle system, so that unit is not

cold.

Phenomenon of failure:

a, lower pressure of discharging

b, lower temperature of discharging.

Change a new filter

2.NO COOL

(Popular failure reasons are below):

Reason analysis Solutions:

1) Leakage of gas

Phenomenon of failure:

a, leaking fast

b, leaking slowly

c, no voice of liquid flowing

d, cut off charging tube, no gas goes

out.

First f ind out the point of leaking on tube, and

then sealed it, vacuuming it, f inally recharge

with gas.
Note：

If you find oil on somewhere, it is possible that

leakage point is there.

2)There is some thing

that blocked the liquid

cycle system

A,Ice blocking

Sometime because unknown reason

water comes into liquid cycle

system, the capillary will be blocked

by water after unit runs for period of

time.

Phenomenon of failure:

The unit works well in the incept ion,

after period of t ime the ice appears

in the capillary and becomes more

and more, till blocks the hole of

capillary completely. In the moment

you can f ind the ice on the

evaporator defrosts. The noise of

liquid flow disappears. The pressure

of absorbing becomes negat ive.

First stop unit for several minutes, and then

open charging tube, discharge all of gas. Blow

the cycle system with gas of nitrogen, and then

recharge Gas, finally sealed the system.

The phenomenon above will appear

again and again.

The way to check ice blocking:

Warm the capillary with a hot towel,

after a while the ice in the capillary

melt, you can hear a sound of gas

flow comes from the capillary

abruptly. The pressure of absorbing

becomes higher. It is Ice blocking.

B, there is offal block the capillary

Phenomenon of failure:

If the capillary is blocked by

something such as offal etc., the

sound of liquid flow disappears.

The ice on the evaporator defrosts

The pressure of absorbing becomes

negative.

Higher temperature of discharging

tube

The way to check offal blocking:

If you warm capillary with the way of

checking ice blocking, there is no

change. It must be offal blocking.

First stop unit for several minutes, and then

open charging tube, discharge all of gas. Blow

the cycle system with gas of nitrogen. Change

a new capillary and filter, and then recharge

Gas, finally sealed the system.

COMPRESSOR NEVER STOPS：

Reason Solutions

1) The setting temperature is not reasonable. Readjust the temperature sett ing.

2) the sensor is bad. Replace the sensor.

3) Seal of door is damaged. Replace the gasket

4) Too much food in the refrigerator Please put the food properly.

5) Wind door is broken. Replace wind door.

6) Fan motor is broken. Replace fan motor

Note:

◆Before doing these operat ions above, disconnect the main power supply. Failure to do so could result in

electrical shock or personal injury.

◆ In case of any detailed technical information please check with the technical specif ications.