Troubleshooting Guide (Table 19) - Honeywell T7350 User Manual

TROUBLESHOOTING GUIDE (TABLE 19)

Symptom
Display will not come on. Thermostat is not being powered.
Temperature display is
incorrect.
Temperature settings will
not change.
(Example: Cannot set
heating higher or cooling
lower.)
Room temperature is out
of control.
Heat will not come on.
Table 19. Troubleshooting Information.
Possible Cause
Room temperature display has been
recalibrated.
Thermostat is configured for °F or °C
display.
Bad thermostat location.
Display shows three dashes and a degree
sign (all systems shut down).
Upper or lower temperature limits were
reached.
Occupied setpoint temperature range
stops were configured.
Keypad is locked. When a locked key is
pressed, LOCKED appears momentarily
on the LCD.
Remote temperature sensing is not
working.
No power to the thermostat.
Thermostat minimum off time is activated. • Wait up to five minutes for the system to respond.
System selection is set to Off or Cool.
DAT high limit has been reached, or
OAT lockout is engaged.
T7350 COMMERCIAL PROGRAMMABLE THERMOSTAT
Check that X terminal is connected to the system
transformer.
Check for 24 Vac between X and RH or RC terminals.
If missing 24 Vac:
• Check if circuit breaker is tripped; if so, reset circuit
breaker.
• Check if system fuse is blown; if so, replace fuse.
• Check if the HVAC equipment power switch is in the Off
position; if so, set to the On position.
• Check wiring between thermostat and HVAC
equipment. Replace broken wires and tighten loose
connections.
If 24 Vac is present, proceed with troubleshooting.
Use PDA configuration software or TStatSpec software to
recalibrate as desired.
Press both Run Schedule and Copy, then reconfigure the
display.
Relocate the thermostat.
T7350 is set for remote sensing and sensor is missing or
circuit is either open or shorted.
Check the temperature setpoints:
• Heating limits are 40° to 90° F (7° to 31° C)
• Cooling limits are 45° to 99° F (9° to 37° C)
Using a PDA or TStatSpec software, check setpoint stops.
If necessary, reconfigure the stop(s).
• Use PDA (Set, Display) or TStatSpec software to
unlock keypad.
• Press both Run Schedule and Copy, then change
keypad lock level.
Check all remote sensors.
Check that X terminal is connected to the system
transformer.
Check for 24 Vac between X and RH terminals.
If missing 24 Vac:
• Check if circuit breaker is tripped; if so, reset circuit
breaker.
• Check if system fuse is blown; if so, replace fuse.
• Check if the HVAC equipment power switch is in the Off
position; if so, set to the On position.
• Check wiring between thermostat and HVAC
equipment. Replace broken wires and tighten loose
connections.
If 24 Vac is present, proceed with troubleshooting.
• Use PDA or TStatSpec software to configure heating
response.
Set system selection to Heat or Auto.
• If the setpoints are correct, do nothing.
• Use PDA (Heating Config) or TStatSpec software to
adjust or disable DAT high limit and/or OAT lockout.
• Check HVAC equipment to ensure proper operation.
25
Action
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