Honeywell COMMERCIAL PROGRAMMABLE T7350 - Manual (Page 18)

T7350 COMMERCIAL PROGRAMMABLE THERMOSTAT
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Step 7. Troubleshooting
Table 11. Troubleshooting Information.
Symptom Possible Cause Action
Display will not
come on.
Thermostat is not being powered. 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.
Temperature
display is
incorrect.
Room temperature display has been
recalibrated.
Use PDA or L ON S PEC ™ configuration software to recalibrate as
desired.
Thermostat is configured for °F or °C
display.
Press both Run Schedule and Copy, then reconfigure the display.
Bad thermostat location. Relocate the thermostat.
Display shows three dashes and a
degree sign (all systems shut down).
T7350 is set for remote sensing and sensor is missing or circuit is
either open or shorted.
Temperature
settings will not
change.
(Example: Cannot
set heating higher
or cooling lower.)
Upper or lower temperature limits
were reached.
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)
Occupied setpoint temperature
range stops were configured.
Using a PDA or L ON S PEC ™, check setpoint stops. If necessary,
reconfigure the stop(s).
Keypad is locked. When a locked
key is pressed, LOCKED appears
momentarily on the LCD.
• Use PDA or L ON S PEC ™ (Set, Display) to unlock keypad.
• Press both Run Schedule and Copy, then change keypad lock
level.
Room
temperature is out
of control.
Remote temperature sensing is not
working.
Check all remote sensors.
Heat will not come
on.
No power to the thermostat. 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.
Thermostat minimum off time is
activated.
• Wait up to five minutes for the system to respond.
• Use PDA or L ON S PEC ™ to configure heating response.
System selection is set to Off or
Cool.
Set system selection to Heat or Auto.