Honeywell T7350 User Manual page 26

T7350 COMMERCIAL PROGRAMMABLE THERMOSTAT
Symptom
Cooling will not come on. No power to the thermostat.
System indicator (flame:
heat, snowflake: cool) is
displayed, but no warm or
cool air is coming from
the registers.
63-2605—09
Table 19. Troubleshooting Information. (Continued)
Possible Cause
Thermostat minimum off time is activated. • Wait up to five minutes for the system to respond.
System selection is set to Off or Heat.
DAT low limit has been reached, or
OAT lockout is engaged.
The call for heat or cool is not yet given.
Conventional heating equipment turns the
fan on only after the furnace has warmed
to a setpoint.
Heating or cooling equipment is not
operating.
Check that X terminal is connected to the system
transformer.
Check for 24 Vac between X and 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 or TStatSpec software to configure cooling
response.
Set system selection to Cool or Auto.
• If the setpoints are correct, do nothing.
• Use PDA (Cooling Config) or TStatSpec software to
adjust or disable DAT low limit and/or OAT lockout.
• Check HVAC equipment to ensure proper operation.
Check if any stage indicators (dots next to the system
indicator) are displayed. With no display of stage
indicators, no call for cool/heat via relay is yet given.
For T7350M models only: Check the information screens.
MODHEAT or MODCOOL percentages of zero and 100
indicate an extreme signal from the given terminal. See
Table 15 for details.
Wait one minute after seeing the on indicator and then
check the registers.
Verify operation of heating or cooling equipment in Test
Mode.
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Action