Honeywell TrueDRY DR90 Professional Installation Manual page 20

Troubleshooting (continued)
DR90/120 Service Diagnostic Tree
Dehumidifier not running
JUMP ""DEHU" AND
"R" ON THE
TERMINAL BLOCK
18
IS THE
DEHUMIDIFIER
NO
RUNNING NOW?
YES
IS THE RELATIVE
HUMIDITY OF THE YES
SPACE ABOVE
45% RH?
NO
JUMP FLOAT
TERMINALS
TOGETHER
IS THE
DEHUMIDIFIER
YES
RUNNING NOW?
NO
DOES THE
DEHUMIDIFIER
NO
HAVE POWER?
YES
IS 24 VAC
PRESENT ACROSS
NO
"R" AND "C"
TERMINALS?
YES
UNPLUG THE LOW
PRESSURE SWITCH
CONNECTORS AND
JUMP THE WIRES
TrueDry DR90/DR120 Dehumidification System 69-2690EFS—04
CHECK FOR CLOGGED
DRAIN OR FIX FLOAT
SWITCH ISSUE
VERIFY POWER AT
OUTLET
CHECK WIRING INSIDE
ELECTRICAL BOX FOR
LOOSE CONNECTIONS
AND POSSIBLE FAILED
TRANSFORMER
NO
DOES THE
COMPRESSOR
COME ON?
YES
PRESSURE SWITCH
HAS FAILED OR THE
SYSTEM IS LOW ON
REFRIGERANT
CHECK CALIBRATION
AND OPERATION OF
DEHUMIDISTAT
DEHUMIDIFIER IS
OPERATING NORMALLY.
WAIT FOR RH TO RISE
TO TEST AGAIN.
M33760