Robertshaw Smart Sense Series Installation Manual page 55

Symptom
"Locked" appears
on LCD and
heating or cooling
will not operate.
Heating or
cooling runs in
deadband.
Thermostat has
no display.
Problem
This is not a fault.
Outside air temp too high to
require heating.
Outside air temp too low to
require cooling.
Thermostat incorrectly set to HP
mode.
Thermostat keeps reversing
valve energized after heating
/ cooling has stopped to limit
decompression noise from AC
system.
Minimum run period has not yet
expired. HEATING or COOLING
flashes in the LCD.
Compressor and reversing valve
wiring crossed in HP mode (Sw2
= ON).
Power failure or faulty
thermostat.
Solution
The HO = XX and/or CO = XX value
is inhibiting heating or cooling
calls. Change these values in the
Advanced Installer Menu. See
page 34.
Set Sw2 = OFF and retest heating
and cooling operation.
Sw7 sets minimum run period to
two or six minutes.
Check W1 and Y1, Y2 for correct
connections.
Check for 24V AC on the 24 and
24T terminals. Check output from
transformer.
55