Honeywell CT3550 - Manual (Page 18)

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If You Have a Problem
Table 4. Solution Guide.
If... Then…
Display does not appear. • Make sure the batteries are installed correctly.
• Make sure the thermostat is mounted and latched on the wallplate.
Mount and latch the thermostat on the wallplate if it is not.
Temperature settings will not change
(example; cannot set the heating
higher or the cooling lower). • Make sure the temperature setpoints are:
40 to 90°F (4.5 to 32°C) for heating.
45 to 99°F (7 to 37°C) for cooling.
Heating does not come on. • Make sure the heating setpoint is above the room temperature.
• Make sure the circuit breaker is not tripped, and reset it if necessary.
• Make sure the power switch at the equipment is in the On position, and
set it to On if it is in the Off position.
• Wait five minutes for the system to respond.
• Set the system key to Heat.
Cooling does not come on. • Make sure the cooling setpoint is below the room temperature.
• Make sure the circuit breaker is not tripped, and reset it if necessary.
• Make sure the system switch at the air conditioner is in the On position,
and set it to On if it is in the Off position.
• Wait five minutes for the system to respond.
• Set the system key to Cool.
System on indicator ( = heat, =
cool) is lit, but no warm or cool air is
coming from the registers.
Wait five minutes after seeing the flame or snowflake and check the registers
again. If no there is no hot or cool air coming from the registers, refer to
Heating does not come on or Cooling does not come on. If all of this has been
checked, contact your local heating and cooling contractor.
Display flashes during programming. The temperature setting limit has been reached. The heating setting range is
40°F to 90°F (4.5°C to 32°C). The cooling setting range is 45°F to 99°F (7°C
to 37°C).