Whirlpool MAH3000 Dishwasher User Manual


 
Section 4. Electrical Components & Testing
4-7
16010486 (16008373-05)
Revised 02/01
©2001 Maytag Appliances Sales Company
HEATER ASSEMBLY
The heater assembly located in the sump
area of the outer tub is only on the
MAH7500, LCD washer only. A thermistor
located in the heater assembly monitors
the water termperature in order to cycle
the heater on/off to regulate the proper
temperatures.
After the wash level has been reached, the
control will turn the heater on until the
heater thermistor indicticates the tempera-
ture reaches or exceeds the target main
wash temperature. Then the control will
de-energize the heater. The heater will be
turned back on when the heater thermistor
indicates the temperature falls below the
target main wash temperature  5°F during
the main wash. The control will cycle the
heater off again when the temperature
reaches the target wash temperature.
The intent is to keep the temperature
between the target main wash tempera-
ture and 5°F below that. When the heater
is off, it will remain off for at least 10 sec-
onds, and when the heater is turned on, it
will remain on for at least 10 seconds. The
heater should be turned off and will re-
main off when the maximum heater on
time limit is reached (37 minutes), or the
end of the wash period is reached. The
heater will be turned off at the beginning
of bleach fill at the end of main wash. The
heater will be turned off during add fills.
Heater Will Not Turn On
1 The heater will not turn on if the door is
not closed or if there is a problem with
the door sense circuit.
Figure 4-9
9. Unplug the washer power cord and
replace motor control board connec-
tor JP4 when finished.
Figure 4-8
b. If the fuse is functioning, check the
six semiconductors on the heat sink
visually for any damage. If damaged,
replace motor control/wire harness
assembly complete.
c. If no visible damage is present,
check motor windings for any open
circuits. (See Figure 4-8 & 4-9) Re-
place motor if necessary.
Figure 4-7