Honeywell T7350 System Engineering page 19

Symptom
Cooling will not No power to the thermostat.
come on.
Thermostat minimum off time is
activated.
System selection is set to Off or
Heat.
System indicator The call for heat or cool is not yet
(flame: heat, given.
snowflake: cool) is
displayed, but no
warm or cool air is
coming from the
registers.
Conventional heating equipment
turns the fan on only after the
furnace has warmed to a setpoint.
Heating or cooling equipment is not
operating.
Table 11. Troubleshooting Information. (Continued)
Possible Cause
T7350 COMMERCIAL PROGRAMMABLE 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.
• Wait up to five minutes for the system to respond.
• Use PDA or L S ™ to configure cooling response.
ON PEC
Set system selection to Cool or Auto.
Check if any stage indicators (dots next to the system indicator) are
displayed. With no display of stage indicators, no call for cool/heat is
yet given.
For the modulating T7350H1017 only: Check the information
screens. MODHEAT or MODCOOL percentages of zero and 100
indicate an extreme signal from the given terminal.
Wait one minute after seeing the on indicator and then check the
registers.
Verify operation of heating or cooling equipment in self-test.
19
Action
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