McQuay LIA303

27
Troubleshooting
Symptom Remedy
No display Check for 24 VAC at thermostat; display is blank when 24 VAC is not present
Time and day of week must be reset after extended power loss
System fan does not come on properly Verify wiring is correct, check Gas/Electric Conguration (see Setting 4, Page 12)
All thermostat buttons are inoperative Verify 24 VAC is present; unit locks out when 24 VAC is not present
No response with rst button press First button press activates backlight only
Program schedule activates at the wrong time Check time (AM/PM) set on thermostat (see Setting the Time, Page 20)
Thermostat turns on and off too frequently Adjust temperature differential (see Conguration Mode Setting 2, Page 11)
Thermostat does not follow program Verify it is operating in program mode (PROG displays); check time (AM/PM); check if in 2
hour program override
Fan runs continuously Press FAN (right) button to turn fan off
Fan turns on occasionally
Program Mode: Check programmable fan setting in program schedule
(see Page 22)
Status indicator light not on during call Turn status indicator function on (see Conguration Mode Setting 12, Page 15)
Room temperature is not correct Calibrate thermostat (see Conguration Mode Setting 8, Page 14)
If remote sensor is used, check S1 and S2 terminal connections
displays when any button is pressed Thermostat has the button lockout function activated (see Lockout Feature, Page 23 and
Conguration Mode Setting 5, Page 13)
on display instead of room temp. Check for a bad connection at S1 and S2 terminals, if used (see Conguration Mode Setting
10, Page 14)
Heat or Cool not coming on Verify wiring is correct, verify RC/RH jumper is in place (for single transformer system)
Remote or outdoor sensor not accurate Press SYS and Down buttons simultaneously to display remote or outdoor temperature. Verify
connections at S1 and S2 terminals.
Problem not listed above Press Reset button once*
* Reset Button Function: Time and day are reset, conguration and program settings are unchanged.