Dacor Built-In Dishwasher User manual

Service Manual
Built-In Dishwasher

Table of ConTenTs
Section 1 - Safe Servicing Practices............................. 1-1
Section 2 - Operation ...................................................2-1
Static Fill..............................................................................2-1
Dynamic Fill.........................................................................2-1
Wash System.......................................................................2-2
Soil Sensing........................................................................2-2
Main Wash/Temp Assure....................................................2-3
Temperature Controls.........................................................2-3
Rinse Phases .....................................................................2-4
Condensate Drying.............................................................2-4
Section 3 - Cycle, Systems & Components ...............3-1
Dishwasher Control............................................................3-1
Auto Wash.........................................................................3-1
Heavy Wash......................................................................3-1
Normal Wash ...................................................................3-1
Short Wash........................................................................3-1
Rinse Hold.........................................................................3-1
Component Function Test .................................................3-1
Water/Service Test............................................................3-1
Entering the Water/Service Test........................................3-2
Water Temperature Test Mode..........................................3-2
Soil Sensor Test Mode......................................................3-3
Electronic Control and Keypad Assembly.........................3-3
Control Board Plugs..........................................................3-3
Fill System...........................................................................3-3
Inlet Water Valve .................................................................3-3
To Check Inlet Water Valve...............................................3-4
Pressure Switch Assembly................................................3-4
Low Water Level Switch.....................................................3-4
Checking Low Water Level Switch....................................3-5
High Water Level Switch....................................................3-5
Checking High Water Level Switch...................................3-6
Wash Motor .........................................................................3-6
Checking the Wash Motor.................................................3-6
Checking the Tachometer .................................................3-6
Heater...................................................................................3-7
Temperature Sensor and Soil Sensor...............................3-7
Checking the Thermistor...................................................3-7
Checking the Soil Sensor..................................................3-8
Drain Pump..........................................................................3-8
Checking the Drain Pump.................................................3-8
Dispenser.............................................................................3-9
Checking the Dispenser....................................................3-9
Fan Dry Unit ......................................................................3-10
Checking Fan Dry Motor.................................................3-10
Section 4 - Service & Disassembly.............................4-1
Safety Precautions .............................................................4-1
Door Panel...........................................................................4-1
Control.................................................................................4-1
Dispenser.............................................................................4-2
Lower Access Panel...........................................................4-2
Door Latch/Door Switch.....................................................4-2
Upper Spray Arm ................................................................4-3
Lower Spray Arm................................................................4-3
Center Spray Arm and Upper Rack Manifold...................4-4
Main Delivery Tube.............................................................4-4
Upper Spray Arm Mount ....................................................4-5
Bottom Door Seal ...............................................................4-5
Door Seal.............................................................................4-5
Water Valve..........................................................................4-6
Cabinet Removal.................................................................4-6
Door Spring.........................................................................4-7
Hinge “C” Arm ....................................................................4-7
Door Seal Retainer..............................................................4-8
Pressure Switch Assembly................................................4-8
Thermistor/Soil Sensor......................................................4-9
Inline Heater .......................................................................4-9
Drain Pump........................................................................4-10
Wash Motor .......................................................................4-10
Capacitor ...........................................................................4-11
Blower Assembly..............................................................4-12
Sump..................................................................................4-12
Side Vent and Fill Hose....................................................4-13
Section 5 - Troubleshooting Tips................................5-1
Section 6 - Parts Breakdown.......................................6-1
Section 7 - Electrical Diagram.....................................7-1

Page 1-1
seCTion 1 - safe serviCing PraCTiCes
To avoid personal injury and/or property damage, it is important that Safe Servicing Practices be
observed. The following are some limited examples of safe practices:
DO NOT attempt a product repair if you have any doubts as to your ability to complete it in a safe
and satisfactory manner.
Before servicing or moving an appliance:
• Remove the power to unit.
• Turn off the gas supply.
• Turn off the water supply.
3. Never interfere with the proper operation of any safety device.
4. USE ONLY REPLACEMENT PARTS CATALOGED FOR THIS APPLIANCE. SUBSTITUTIONS MAY
DEFEAT COMPLIANCE WITH SAFETY STANDARDS SET FOR HOME APPLIANCES.
5. GROUNDING: The standard color coding for safety ground wires is GREEN, or GREEN with
YELLOW STRIPES. Ground leads are not to be used as current carrying conductors. It is
EXTREMELY important that the service technician reestablish all safety grounds prior to completion
of service. Failure to do so will create a hazard.
6. Prior to returning the product to service, ensure that:
• All electrical connections are correct and secure
• All electrical leads are properly dressed and secured away from sharp edges, high-temperature
components, and moving parts
• All non-insulated electrical terminals, connectors, heaters, etc. are adequately spaced away from
all metal parts and panels
• All safety grounds (both internal and external) are correctly and securely connected
• All panels are properly and securely reassembled
ATTENTION
This service manual is intended for use by persons having electrical and mechanical training and a
level of knowledge of these subjects generally considered acceptable in the appliance repair trade.
Dacor cannot be responsible, nor assume any liability, for injury or damage of any kind arising from
the use of this manual.
1.
2.
Section 1 - Safe Servicing Practices

Page 2-1
DaCor builT-inDishwasher serviCe Manual
In order to address service issues with the Dacor Built-In Dishwasher, the primary elements
of its operation are described below, as well as its physical components.
Static Fill
The cycle begins by activating the drain pump, ensuring the sump is empty. Operation then proceeds to
the fill stage where the fill valve regulates inlet water to 1.08 GPM between 20 and 120 psi. A fill hose
is attached to the fill valve and clamped to the bottom of an air gap mounted on the left hand side of
the tub. (The air gap prevents the siphoning of wash water back into the water supply system should
the water pressure drop to less then atmospheric pressure.) The inlet water enters the tub through
the vent opening on the left sidewall of the tub. As the fill continues, both the time of the fill and the
amount of water in the sump are monitored by the electronic control.
The pressure switch assembly mounted to the right side front frame has two pressure switches; a low
water level and a high water level switch. The contact in the low water level switch is open until the
water reaches the proper level in the sump. At this point, the switch closes (neutral to P3-9), starting
the Dynamic Fill.
Dynamic Fill
The closed circuit from the pressure switch starts the wash motor. The wash motor gains speed at the
rate of 100 RPM/second until full speed is attained. The water level inside the sump falls as the wash
motor gains speed. This opens the circuit on the low level pressure switch, allowing the water valve to
introduce more water to the tub. Once the wash motor reaches full speed, the inlet water continues to
fill until the low level pressure switch is reactivated (neutral to P3-9). This completes the fill phase of
the cycle.
PRESSURE SWITCH ASSEMBLY – FIGURE 1
Section 2 - Operation
Low Water Level Switch
High Water Level Switch

Page 2-2
seCTion 2 - oPeraTion
Wash System
Once filling is complete, the dishwasher enters the
pre-wash phase. The pre-wash phase conditions the
soil with water and detergent to prepare it for removal
in the main wash phase.
Once water enters the tub, the pump draws the water
into the sump through a primary filter at the bottom
of the tub to prevent food from circulating through the
wash system and redepositing on the dishes. In the
center of the primary filter is the lower spray arm and
drain filter assembly. The drain cap, snapped into the
drain cup, prevents food particles from entering the
drain section of the sump.
As the wash water flows through the filters, soil levels
and water temperatures (see Soil Sensing section, this
page) are measured by the Soil Sensor/Thermistor
assembly. The wash motor discharges the wash water
through two ports, feeding the lower, center, and
upper spray arms. The larger of the ports feeds water
through a “Y” hose to separate the lower and center
spray arm wash water. The water flowing to the center
spray arm first passes through an inline water heater
before entering the delivery tube. The water flowing to
the lower spray arm passes through the sump on its
way to the lower spray arm.
Soil Sensing
Soil sensing is performed in all wash cycles except the Rinse Only cycle. Mounted on the right side of
the sump, the soil sensor transmits light from a transmitter to a receiver to measure the amount of soil
in the water. This information will be used by the control to determine the length of the cycle.
Once pre-wash loosens food on the dishes, the motor stops for 30 seconds. This allows the wash water
and food soils to settle for the soil sensor to check the soil levels in the water.
Now that this reading is taken, the dishwasher drains the dirty water and fills again for the pre-wash
rinse. Once this rinse is complete, the wash motor pauses again, a soil level measurement is again
taken. The control uses these readings to adjust the wash cycle to ensure a clean load of dishes.
FIGURE 3
FIGURE 2
Sump
“Y” Hose
Inline Heater
Wash
Motor
Thermistor Soil Sensor

Page 2-3
DaCor builT-inDishwasher serviCe Manual
Main Wash/Temp Assure
After the final reading by the soil sensor, the unit drains before
starting to fill for the main wash. The tub fills, with the wash
motor starting after the low level pressure switch is activated.
The detergent dispenser now opens, introducing detergent
into the wash cycle. The electronic control checks the water
temperature through the thermistor, energizing the inline heater
to maintain or heat the wash water entering the second level
spray arm.
The main wash temperature has been predetermined for the
wash cycle selected. At this point, depending on the required
temperature (Temp Assure), the electronic control pauses the
time remaining to allow the wash water to heat to the desired
setting. If Temp Assure is not reached, the dishwasher pauses
time between 0 and 10 minutes to allow the temperature to
increase during several periods of the main wash. Once the main
wash cycle is completed, the dishwasher goes through the drain
phase before filling for the rinse phase of the cycle.
Temperature Controls
Options allow the consumer the choice to control the temperature at which the main wash operates.
The main wash water can be heated to increase the performance of the chosen wash cycle.
If the High Temp option is chosen, the required temperature (Temp Assure) during the main
wash is increased to 140°F. The control will pause the time remaining for up to 10 minutes
to allow the water to heat to this temperature. Whether or not the water temperature
reaches this in 10 minutes, the cycle continues without indication that it reached or did not
reach this temperature.
When the Sanitize option is chosen, the National Sanitation Foundation requires, in the final rinse cycle,
that 155°F be reached and maintained for a certain amount of time. During the final rinse, the control
pauses the time remaining for up to 30 minutes to reach Temp Assure (155°F for Sanitize) before
proceeding to the end of the cycle. Should the cycle meet the requirements defined by the Sanitize
option, the Sanitize ring will remain lit following the completion of the cycle. The ring will not light if
Temp Assure is not met.
INLINE HEATER – FIGURE 4

Rinse Phases
The first rinse phase follows the pre-wash portion of a wash cycle. During this rinse phase, the motor
ramps up by 100RPM/second to full speed (2800RPM). Once at full speed, however, the motor will cycle
between 1600RPM and 2800 RPM throughout the rest of this rinse phase. This motor action aids in the
removal of food from the dishes so it can be filtered from the water.
The final rinse phase begins, following the end of the main wash. Rinse agent is added to the
water during the final rinse. Rinse agent speeds drying, removes water spots, and water streaks
from glassware.
If the Sanitize option has been chosen, the control will pause the time remaining to allow the heater to
increase the water temperature to 155°F. This delay will last up to 30 minutes before resuming the rest
of the cycle. The Sanitize outer ring will light following the wash only if 155°F is achieved.
FIGURE 5
Condensate Drying
This dishwasher is designed and equipped with a
condensate drying system. Steam is drawn from the
tub by the condensate fan and forced through the
condensate duct. As it flows through the condensate
duct, the cool surface of the baffles condenses the
steam into water allowing the now cooler and drier
air to exit into the tub through the condensate vent.
The condensate vent is also the exit for the water
from the condensate duct into the
tub to be drained.
This circulation starts before the unit has completed
draining and continues for the rest of the drying
phase of the wash cycle. The air intake and
condensate vent are shown in Figure 6.
The final operation of the wash cycle energizes the
fill valve long enough to allow the soil sensor to
recalibrate itself with fresh, clean water.
Page 2-4
seCTion 2 - oPeraTion
Blower Fan
Air Duct
Intake
Side Vent
Air Return

Knowledge of the dishwasher’s cycles and systems is necessary in diagnosing any potential
operational problems. Methods for diagnosing these problems, such as taking resistance
readings and testing for closed circuits are outlined in the following section as well.
Dishwasher Control
All of the functions and operations of this dishwasher are dictated and monitored by the electronic
control. The control maintains the proper water temperature in the wash and rinse cycles to ensure
proper cleaning for the wash cycle selected. (This temperature may not be the same for all cycles.)
The control also monitors the soil concentration in the water with the use of a turbidity sensor mounted
in the sump.
Auto Wash
This cycle factors in the size of the load, the amount of soil on the dishes, and the temperature of the
water to create an appropriate cycle for each load. Auto wash uses water temperature to determine
the length of the wash cycle. Water temperature is monitored to assess the rate at which the water
temperature decreases. A rapid decrease in temperature alerts the control to extend the wash time.
(Larger loads have higher rates of temperature decrease, therefore longer wash cycles.)
As the water is assessed for temperature changes, it is also adjusted to maintain proper temperature
throughout the cycle. The control also checks the soil concentration in the water to determine the
number of rinses needed for cleaning.
Heavy Wash
This cycle is intended for heavy soil levels. The water temperatures for both wash and rinse cycles are
automatically selected. It includes a high temperature wash and sanitize rinse. Soil sensing is used in
this cycle.
Normal Wash
This cycle is intended for normal soil level. All options (high temperature wash, sanitize rinse, and delay
start) are available at the user’s discretion. Soil sensing is used in this cycle.
Short Wash
This cycle is intended for light soil levels. All options (high temperature wash, sanitize rinse, and delay
start) are available at the user’s discretion. Soil sensing is used in this cycle.
Rinse Hold
This cycle is intended for dishes that are to be washed later. It is a rinse-only cycle; options and soil
sensing are not available.
Component Function Test
Water/Service Test
The service test will check the electronic control’s ability to run all functions of the dishwasher.
This test may be entered from an idle mode or the power failure mode, however different pads
are used to activate.
Section 3 - Cycle, Systems & Components
Page 3-1
DaCor builT-inDishwasher serviCe Manual

Page 3-2
seCTion 3 - CyCle, sysTeMs & CoMPonenTs
Component Function Test (continued)
Entering the Water/Service Test
From Power Failure
While the control displays power failure or flashing lights, press and hold the Short wash and the Rinse
& Hold pads simultaneously for one second. The dishwasher will start through the test cycle.
From Idle
With no cycle selected and the dishwasher sitting idle, press and hold the Hi-temp and the Start pads
simultaneously for one second. The dishwasher will start through the test cycle.
The chart below shows the complete Water/Service Test cycle. To manually move to the next phase
of the cycle press the Start pad. If at any time the door is opened the test cycle will end and flashing
lights will come on showing power failure. The Sanitize LED will light at the end of test to check the
LED. If the rinse aid dispenser is empty, the display will read LO to indicate the contact in the dispenser
is closed.
Water Temperature Test Mode
This test is for testing the thermistor in the sump as well as the control.
Start a Normal wash cycle and allow the dishwasher to fill and wash for two minutes at which time,
press the Start/Cancel pad twice (2). This will stop the dishwasher and send it to idle.
With the dishwasher in idle press and hold the Normal wash and the Start/Cancel pads
simultaneously will start the test. The test will show a two digit display for the temperature of the
water (from 0°F to 99°F). If the water temperature is over 99°F a decimal point will be displayed
to show 100°F, then the added degrees over. This reading will be updated every three seconds until
the Start/Cancel pad is depressed to stop the test.
1.
2.
Step
Description
Time
Water Valve
Wash Motor
Drain Pump
Heater
Dispenser
Fan
Sensing LED
Drying LED
Sanitized LED
Dispenser Low LED
Clean LED
1 Fill / Dispenser
3 Wash / Heat
4 Pause
5 Wash / Heat
6 Wash / Heat / Dispenser
7 Drain
Completion
* Dynamic fill - water valve is open until pressure switch is closed
2 Fill / Dispenser / Wash
8 Dry
59 1 0 0 0 0 0 1 0 0 0 0
21 1 0 0 1 0 1 0 0 0 0 *
45 0 1 0 1 0 0 1 0 0 0 0
0.6 0 0 0 0 0 1 0 0 0 0 0
75 0 1 0 1 0 0 0 0 0 0 0
80 0 1 0 1 1 0 0 0 0 0 0
90 0 0 1 0 0 0 0 0 0 0 0
90 0 0 0 1 0 1 0 1 0 0 0
460.6 1 0/1 1

Component Function Test (continued)
Soil Sensor Test Mode
This tests the sensor for proper operation as well as the value that the sensor is detecting.
To activate the test you must press and hold the Heavy and Start pads simultaneously.
When the test mode is activated, the digit display will show the turbidity value of the sensor.
This display will be a voltage reading in the decimal value.
To terminate this test press the Start pad.
Electronic Control and Keypad Assembly
The control on the dishwasher consists of the control board and the switch assembly. The switch is
installed into the top of the outer door panel, an elastomer keypad, used to actuate the switch, is
inserted into holes in the top of the outer door panel. The keypad assembly is attached to the control
board with a connecting ribbon. The keypad is held in place by a spacer that is clipped to the top of the
mount holding the control board. The control is mounted to a carrier panel that is attached to the outer
door panel. It is covered with a mylar blanket.
Control Board Plugs
Throughout this section references are made to the plug and pin location on the electronic control.
Figure 7 shows a picture of the electronic control pointing out plug numbers as well as pin and color of
the wire in each location.
Fill System
Two major components in the fill system are the inlet water valve and the pressure switch assembly.
Inlet Water Valve
The inlet valve is an electrically controlled shut-off valve that is used to allow water to enter the
dishwasher. The valve has a flow restrictor to regulate the water flow to 1.08 GPM at between 20 and
120 psi into the tub. The inlet valve is wired to the electronic control and is opened and closed by the
control. The inlet water valve is located on the front left frame leg just behind the lower front panel.
1.
2.
3.
FIGURE 7
Page 3-3
DaCor builT-inDishwasher serviCe Manual
Plug #1
#1 Black
#8 Gray
Plug #2
Black 1
Red 2
Purple 3
Brown 5
Orange 6
White 7
Plug #3
1 White
2 Brown
3 Blue
4 Black
5 Yellow
6 Brown
7 Black
8 White
9 Orange
10 Blue
11 Red