Delfa WQP12-9242B, WQP8-9241B Technical & Service Manual
Contents
Technical Service Manual
Dishwasher
Specification 2
Test program 24-28
Theory of parts 5-23
Function Description 3-4
Inspection 29-33
Location 5
PCB 6-7
Inlet valve 8-10
Drain pump 11-12
Heater 13-14
Washing pump 15-16
Procedure 25
Error code 26-28
Water circuit 3-4
Pressure switch 17
NTC 18-19
Flowmeter 20-21
Safety Hose 22-23
Troubleshooting 34-38
SAFETY NOTICE
This documentation is only intended for qualified technicians
who are aware of the respective safety regulations.
- 1 -
Specifications
For the basic operation instructions, please refer to the
instruction manual attached with each unit.
Electrical supply 220-240V, 50Hz
Supply water pressure 0.04MPa-1.0MPa
Supply water temperature below 60℃
- 2 -
Models:WQP12-9242B WQP8-9241B
washing pump
pressure switch
drain pumb
drain hose
over flow switch
air breaker
inlet valve
inlet hose
Regeneration water route
upper spray arm
top spray
tube
Inlet water route
lower spray arm
softener
Water circuit scheme
regeneration valve
Cycle water route
Drain water route
Water Circuit Function Description->
- 3 -
Process of water inlet (indicated by magenta route)
In this process, regeneration water route is cut off, main water route is open. The water in the main water
route is softened when pass through the softener, and then enter in the tub. During this phase, some of inlet
water will be stored in the air breaker to be regenerating water.
Process of cycle washing (indicated by blue route)
Cycl e washing act ion is driven b y washing pum p motor. Wa ter can obtain the power during it passing through
the working washing pump, then be pumped into spray arm, pass from spray ar m nozzles, over the dishes,
into sump ,where connect to washing pump, and to g et in the next wa ter cycle.
Process of regeneration (indicated by green route)
Regeneration valve is open, the regenerating water dissolve salt in the s alt chamber o f softener, an d then
ente r in the resin ta nk to reactiv ate the resin .
Water Circuit Function Description->
- 4 -
Location Theory of parts->
Inlet valve
Washing pump
Capacity
Softener
Overflow switch
Filter system
Heater
Over Heat Proof
Micro-switch
Dispenser
Sump
Water inlet
Air breaker
Pressure switch(83/63)
(only for m od els whose w at er fillin g
be contro ll ed by press ur e switch)
Pressure switch(140/120)
Please Note: Exploded view and part list of each model have some different visions, so
please refer to newest vision Midea sent you.
- 5 -
PCB Theory of parts->
Printed Circuit Board is the control center of dishwasher, which receive and process signal
from components, send order to components and deal with the feedback information, etc.
Removing the control panel
The control panel can be removed from dishwasher door.
1. Remove the six screws securing the control panel to the door.
2. The control panel will drop down and be free of the door. But, the wiring will
still connected to the control panel.
S
08
1
2
on
Off
Access PCB
3. Disconnect the connector form PCB.
4. Remove the screws securing the PCB to control panel.
5. Remove the PCB.
6. Reverse the above procedure to install.
PCB
Note: For the majority of models, the PCB is located behind the control panel. The minority
of models locate the PCB on the side of strengthening muscle. You can judge the location by
the newest exploded view Midea sent you.
- 6 -
PCB Theory of parts->
Map of PCB
Description
Mark Function
HEAT Output for Hea ting Element
ACL Input of live wire
ACN Input of bull line
IS Input of Door Switch
EV1-L Firewire input of inlet valve
RE Thermister
ML Washing Pump
PS Drain Pump
D/ED Dispenser
EV1 Inlet valve
EV2 Softener
EV3 Halfload Valve
ISS Salt detect
ISB Rinse detect
IAQS Overflow detect
FM Flowmeter
FAN Fan
PO Pressure Switch(83/63)
Note: This map is applies to 9378A model.
There is small pole’s location difference
between different models.
But the marks on PCB have the same meaning
.described on the left side
- 7 -
Technical data
Location of inlet valve
Appearance
Inlet Valve Theory of parts->
The work principle
The inlet valve is electromagnetic valve that decide whether water enter or not. Valves are
normally closed. Each time the appliance requires water, the controller will convey an
electric signal to the coils to open the valves.
The inlet valve consist of electric coil, valve body, valve pole, filter etc.
In a word, the electromagnetic valve can act to allow water enter into machine, when it
receive the order given by controller.
to air breaker
connect to
inlet water hose
terminals
electric coil inside
The defeat point
1. The valve coil is broken, so the valve can’t open. It will cause the E1 error.
2. The filter is jammed, so water can’t enter. It will cause the E1 error.
3. The connector is loose, so the valve can’t open. It will cause the E1 error.
4. The valve pole is rusted or locked by dreg, so the valve can’t open or close. It will cause
the E1 or E4 error.
Nominal voltage 220-240VAC
Frequency 50/60Hz
Resistance Approx:3.4－4.3kΩ
100%ED T25
3min/5min T60
Flux 4L/min ±15％
Power 6W
Work Pressure 0.04－1MPa
Work duty
- 8 -
Inlet Valve Theory of parts->
3. Top panel
4. Left side panel
1. Baseboard
2. Left baseboard
5. Middle rear
crosspiece
Inlet valve
Access inlet valve
1. Disconnect power.
2. Remove the water inlet hose. (Note : Be careful of remain water drop.)
3. Remove the baseboard, left baseboard, top panel, left side panel and middle rear
crosspiece.
4. Disconnect the 2 terminal lugs
from the inlet valve.
5. Push the valve from the lower
rear crosspiece to take it off.
6. Remove the clamp and
disconnect the inlet hose (to air
breaker) from the water valve.
7. Reverse the above procedure
to install.
1.Open the control panel and take out the PCB;
2.Unplug the CON3 and P4 wires , then use the multimeter Ω shelf to measure resistance between the blue
wire (EV1) and white wire (IS), the normal resistance is
about 3.4KΩ to 4.3KΩ.
3. I f the measured resistance is not correct, it means the
valve coil is broken or the connector is loose. In this
case, we should check the connection first. If the
problem hasn’t been solved by re-connection, we should
replace the valve..
4.If the resistance is OK, we need to inspect the valve
body.
Inspect inlet valve
unplug
Check electric part
Attention: Build in models have no Baseboard and
left and right baseboard, but adjustable baseboard.
- 9 -
IS
EV1
Inlet Valve Theory of parts->
Check machine part
1. If the electric part is OK, we need to check the machine part.
2. Remove the baseboard, left baseboard, top panel, left side panel and middle rear
crosspiece.
3. Check the valve filter. if the valve filter is blocked, we need clear the residues.
4. If the valve filter is clear and the valve can’t inlet water, check whether valve can act or
not. If it isn’t , we need replace the valve.
5. If the water is continue entering, we need replace the valve.
- 10 -
Drain Pump Theory of parts->
Bottom View
Location of Drain Pump
Technical data
The work principle
to washing pump
connect to drain hose
motor
terminals
Drain pump integrated into sump
The work principle
Drain pump consists of electrical motor, impeller, inlet and outlet.
Drain pump is a kind of pump driven by permanent magnet synchronous motor. The rotor is
made with permanent magnet material, the running inertia of rotor is very small, the stator
consist of silicon steel stack and coil. When the drain pump is on power, the rotor will be
very easy to start.
The defeat point
1. The motor coil is broken, so the drain pump can’t work. It will cause the E2 , E4 or E1 error
.
2. The magnetism of motor rotor is weak, so drain pump cannot work. It will cause the E2, E4
or E1 error .
3. The connector is loose, so the drain pump can’t work. It will cause the E2, E4 or E1 error .
4. The rotor is locked by residues, so the drain can’t work . It will cause the E2, E4 or E1
error .
5.The drain pump assembly rack is loose, it will cause noise.
6.The non-return valve is bad, the remain water is too much.
Explanatory notes: failure of drain pump may cause E1, becaus
Nominal voltage 220-240VAC
Frequency 50Hz
Resistance 150－220Ω
Delivery height 1M
Delivery performance ≥17l/min(230VAC)
- 11 -
Drain Pump Theory of parts->
Check the machine part
1. If the electric part is OK, we need to check the machine part.
2. Remove bottom board.
3. If the non-return valve is wrongly assembled, the tub will remain much water. We need to
re-assemble the non-return valve.
4. If the drain pump is working, but no water drain out or just a little. We should check the
drain hose or drain body.
1. Drain off the water in the dishwasher, and
disconnect the power supply。
(Note : Make sure to remove remained water in the
dishwasher. If not, wet the floor.)
2. Remove four screws on bottom, and then
remove bottom board.
3. Label and disconnect the two terminal lugs from
the drain pump.
4. Remove screws securing the drain pump to
sump, then remove drain pump.
5. Reverse the above procedure to install.
Access drain pump
Inspect drain pump
Check the electric part
1.Open the control panel and take out the PCB;
2.Unplug the CON4 and P4 wires, then use the multimeter Ω shelf to measure the red wire (PS) and white wire
(IS), the normal resistance is about 150Ω to 220Ω.
3. If the measured resistance is not correct, it means the
pump coil is broken or connector is loose. In this case, we
should check the connection first. If the problem hasn’t
been solved by re-connection, we should replace the
drain pump.
4.If the resistance is OK, but it also can’t work, maybe the
magnetism is too weak, so we need to replace the drain
pump.
- 12 -
IS
PS
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