Water Heating / Heat Dry - KitchenAid KMTM704E Series Technical Education

TESTING
DANGER
Door Switch
Electrical Shock Hazard
Only authorized technicians should perform
diagnostic voltage measurements.
After performing voltage measurements,
disconnect power before servicing.
Failure to follow these instructions can result in
death or electrical shock.

Water Heating / Heat Dry

This test will check the wiring to the heater element, hi-limit
thermostat and the heating circuit itself. The following items
are part of the heater circuit.
n Harness/Connection
n Heater Coil
Wash/Rinse
n Hi Limit Thermostat
n Control Board
Test Procedure
Control may be programmed to disable the heater if it detects
a problem with the heating system. Run Diagnostics to clear
the control and allow the heater to turn on again. If heating
problem is not corrected, the control will disable the heater
again.
1. Unplug dishwasher or disconnect power.
2. Remove toe and access panels to access control board.
3. Disconnect P4 from the control board.
Water Heating/Heat Dry and Water Sensing with O.W.I. Sensor (Water/Air/Soil/Tempe
Strip Circuit – Heater Circuit
Heater
Electronic Control
L1
N.O.
BK
P4-2
K3
Heater L1 Relay
(Also see Door
Switch Circuit)
KitchenAid 2015 Microfiltration Dishwashers
n
6-10
Fill
P4
For Service Technician Use Only
13V
V
P9-6
Electronic Control
Motor Power
L1
BK
N.C.
BU/RD BU/RD
P4-3
Hi-Limit
Thermostat
Opens
207°F - 217°F
(97°C - 103°C)
P5
P6
BR
4. Using an ohmmeter, measure resistance between P4, pins
3 and 4.
¾ If the resistance is between 8-30 ohms, go to step 6.
¾ If an open circuit is detected, go to step 5.
5. Visually check the wire connections between the control
board, the heater element and the hi-limit thermostat. If
the connections look good, check for continuity across the
heater element and the hi-limit.
¾ Replace heater element or hi-limit thermostat if it is
electrically open.
¾ Repair or replace wire harness if test fails continuity.
Door
6. Reconnect P4 to control board.
Switch
7. Set voltmeter to AC and connect leads to test-pads
P4-3 & P4-4 on the control board. Plug in dishwasher or
Sensing
reconnect power.
Input
8. Start the Diagnostic Cycle and at the proper interval
N.O.
measure for AC out of the control between P4-3 and P4-4
V
using a voltmeter set to AC.
P9-5
Door ¾ If 120 VAC is measured and heater element is on, go to
step 9.
Switch
Ref
P10-4
¾ If no AC voltage is measured, replace control board.
9. Perform Diagnostic Cycle to verify repair.
¾ If heater related error still exists, perform Water
Sensing test procedure on following page.
10. Unplug dishwasher or disconnect power.
11. Reassemble all parts and panels.
12. Plug in dishwasher or reconnect power.
N.O.
P4-2
Pilot L1 Relay
(Also see Door
Switch Circuit)
BU/WH
P4-4
Heater Element
8Ω - 30Ω
120V, 60 Hz
785W Wet
500W Dry
P7
BU
Dishwasher Strip Circu
(To Heater)
Vent, and Triac Loads)
N.O.
K1
Heater (N) Relay
Micro Pin
P5-2
K2
Electronic Control
Electronic Control
N.O.
K1
Heater N Relay
(Also see Door
Switch Circuit)
P8 P9
RD V
Unplug dis
I
Perform re
I
disconnec
(To Wash Motor,
N.O.
K2
Pilot (L1) Relay
Micro Pin
Electronic Control
Run
Winding
3Ω - 7Ω
TURQ
(LBU)
V
Pin 2
AUX
Y
Winding
6Ω - 10Ω
Motor and Capa
(Wash Pump
120V, 60 Hz, 190W
N
Electro
Cont
WH
P4-1
Hea
Y