Troubleshooting - Honeywell Home T10 Product Data

TROUBLESHOOTING

If you have difficulty with your thermostat, please try the
following suggestions. Most problems can be corrected
quickly and easily.
Display is blank:
• Check circuit breaker and reset if necessary.
• Make sure power switch for heating & cooling system is
on.
• Make sure furnace door is closed securely.
• Make sure the C wire is connected.
Heating or cooling system does not respond:
• Press Menu > System Mode > Heat > Done to set the
system to Heat mode. Make sure the desired
temperature is higher than the indoor temperature.
• Press Menu > System Mode > Cool > Done to set the
system to Cool mode. Make sure the desired
temperature is lower than the indoor temperature.
• Check circuit breaker and reset if necessary.
• Make sure power switch for heating & cooling system is
on.
• Make sure furnace door is closed securely.
• Wait 5 minutes for the system to respond.
Temperature settings do not change:
1. Verify the thermostat is set to the correct mode. Press
Menu-Mode to change mode setting.
2. If the display indicates "screen locked" when you press
the up or down arrow, you can unlock the screen by
selecting menu-security settings.
3. The thermostat may be preventing you from changing
the set-point above or below a certain setting because
of installer configured minimum and maximum settings.
See the ISU settings for 4100 on page 36.
Default minimum and maximum settings:
• Heat: 40 °F to 90 °F (4.5 °C to 32.0 °C)
• Cool: 50 °F to 99 °F (10.0 °C to 37.0 °C)
Q: Heat runs with thermostat in cool or off mode:
A: Does the display show "Freeze Protection active"? If so,
the installer set the thermostat for a freeze protection
temperature that maintains a minimum temperature even
when the thermostat is set to off or cool. This feature is
available on T10 models only and will generate an alert
message if the temperature drops below the freeze
protection setting.
33-00462—05
Aux heat runs in cooling:
• For heat pump systems, verify there is not a wire
attached to W on the UWP.
Cool runs with a call for heat:
• For heat pump systems, verify there is not a wire
attached to W on the UWP.
Cooling runs below set-point:
Cool should never run unless the display is solid blue and
shows "Cooling to" rather than "Cool to".
If ISU 9000 is set for AC with low speed fan or AC with high
speed fan, the T10 or T10+ can run cooling up to 3 degrees
below set-point when humidity is high. It will cool 1 degree
below set-point for approximately every 4% RH above the
dehumidity setting.
Q: Why isn't my heat running?
A: Verify the thermostat is set to heat, em heat, or auto mode
and verify that the heat setpoint is above room
temperature. Does the display indicate "Heating to" with
an orange display screen? If so, the thermostat is
attempting to run the heat.
• If "Heating to" is in an orange display, and heat
does not come on after a short delay, verify the
wire connections, R/Rc slider jumper on UWP (or R,
Rh, and Rc jumpers if an EIM is used with T10+). If
that all checks out, your HVAC contractor can call
Tech Support to verify configuration and for further
troubleshooting.
• If display isn't showing "HEATING TO" (rather than
"HEAT TO") or "WAITING FOR EQUIPMENT" but
heat setpoint is above room temperature, go to
EQUIPMENT STATUS.
68
Fig. 103.
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