3-16
n
Whirlpool Compact Heat Pump Dryer
COMPONENT TESTING
For Service Technician Use Only
TEST #8: Drain Pump (DP)
This test is performed when “water tank full” indicator is
displayed and never turns off (no error code is displayed). The
float switch is in full position.
The following items are part of this system:
Part of Drain System
Heat Pump Dryer
Harness/connection
ü
Drain pump
ü
Water level switch
ü
Appliance Control Unit (ACU)
ü
1. If there is water beneath the front of the dryer, verify
that the dryer is level and that the drain hose is securely
fastened to the drain port.
2. Verify that the drain hose (bottom center of back of dryer)
is not pinched, kinked, plugged, or otherwise restricted.
3. Unplug dryer or disconnect power.
4. Remove top panel, left side panel, and console to access
the machine electronics.
5. Verify visually that ACU connections J3-1 and J3-3 are
connected properly.
DRAIN PUMP / WATER LEVEL SWITCH STRIP CIRCUIT
6. Verify AC voltage according to Test #1: ACU Power Check,
page 12.
7. Access the drain system cover by removing the left side
panel and the pump cover; verify that the drain hose
connections are OK, and that the drain harness (line to
line connection) and float harness (line to line connection)
are connected to the drain system. Check the continuity
of the harness. If there are connectivity and continuity
issues, replace the harness and verify that the “water tank
full” indicator is off and that the pump is active in Service
Test Cycle step S04.
8. If everything is connected and the drain pump still
does not drain water from the sump, measure the
resistance across pins 1 and 3; the resistance should be
approximately 210 Ω. If the reading is infinite (open),
replace the drain pump.
9. If the preceding steps did not correct the problem, replace
the ACU.
Theory of Operation
Drain Pump Operation
During the drying cycle, the drain pump runs 32 seconds
ON and 180 seconds (3 minutes) OFF. This process runs
continuously throughout the drying cycle to prevent water
from reaching a high level in the sump.
Float Switch Operation
If the water level switch detects a high level of water in the
sump (float switch in full position), the pump will be activated
one last time for 3 minutes. If the water level switch does not
change state, the dryer will stop and the “water tank full”
indicator is displayed.
SWITCH LEVELS
Full Position—Switch is OPEN
Empty Position—Switch is CLOSED
CONNECTOR LOCATION (Drain Pump)
See Connector Diagram Figure 1, on page 3-17.
DANGER
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.
L1
ACU
L2
P
DRAIN PUMP / WATER LEVEL SWITCH
J3-3
J13-2
BK
GY
R
GY
DRAIN PUMP
W
GY
J8-4
WATER LEVEL REED SWITCH
OR
ACU
J8-3
J3-1
J13-1
W
W
GY
TR1
210 OHMS
WATER LEVEL
WATER LEVEL
Figure 2 - Drain Pump / Water Level Switch Strip Circuit
