Troubleshooting - Honeywell T7350 Installation Instructions Manual

T7350 COMMERCIAL PROGRAMMABLE THERMOSTAT
TROUBLESHOOTING GUIDE (TABLE 4)
Symptom
Display will not Thermostat is not being powered. Check that X terminal is connected to the system transformer.
come on.
Temperature Room temperature display has
display is been recalibrated.
incorrect.
Thermostat is configured for °F or
°C display.
Bad thermostat location.
Display shows three dashes and a
degree sign (all systems shut
down).
Temperature Upper or lower temperature limits
settings will not were reached.
change.
(Example:
Occupied setpoint temperature
Cannot set
range stops were configured.
heating higher or
Keypad is locked. When a locked
cooling lower.)
key is pressed, LOCKED appears
momentarily on the LCD.
Room Remote temperature sensing is
temperature is not working.
out of control.
Heat will not No power to the thermostat.
come on.
Thermostat minimum off time is
activated.
System selection is set to Off or
Cool.
62-0195—04
Table 4. Troubleshooting Information.
Possible Cause
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 configuration 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, check setpoint stops. If necessary, reconfigure the
stop(s).
• Use PDA (Set, Display) 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.
• Wait up to five minutes for the system to respond.
• Use PDA to configure heating response.
Set system selection to Heat or Auto.
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Action