Troubleshooting - Honeywell T7512B Installation Instructions Manual

TROUBLESHOOTING

IF...
Display will not come on.
Temperature display will not
go lower than 45° (7°C) or
higher than 88°F (31°C)
during programming.
Temperature change occurs
at the wrong times.
Heating does not come on.
Cooling does not come on.
The house is too warm or
too cool.
System ON indicator is lit,
but no heat is coming from
the registers.
The current setting of the
thermostat does not match
the display temperature to
within ±1 degree.
Incorrect room temperature
showing on thermostat
display.
Thermostat is flashing
"CALL xxx-xxxx."
Furnace or air conditioner
cycles too frequently.
Thermostat setting does not
match display temperature.
T7512A,B PROGRAMMABLE LOAD MANAGEMENT THERMOSTAT
T H E N .
• Check for proper HVAC power connections. If unit is a T7512A power stealing
version, verify that cooling circuit provides 8 VA minimum power draw. If not, add
auxiliary shunt contactor, if required.
• You have reached the temperature setting limit. The setting range is 45°F to
88°F (7°C to 31 °C).
• Check the program times for the period in question. Be sure that AM and PM
indications are correct. Make sure the current day and time are correct.
Reprogram if necessary.
• Remember that it takes time for the system to recover.
• Check that the system control on the thermostat is set to HEAT.
• Check the display. If SAVING is displayed, you are in Direct Load Control mode
and the thermostat is under control of the utility. Heating does not come on until
the Direct Load Control period ends or you override Direct Load Control.
• If the temperature setting is higher than the current temperature, and HEAT is
displayed, troubleshoot the heating system.
• Check that the system control on the thermostat is set to COOL.
• Check the system fuse or circuit breaker and replace or reset it, if necessary.
• Check the display. If SAVING is displayed, you are in Direct Load Control mode
and the thermostat is under control of the utility. Cooling will not come on until
the Direct Load Control period ends or you override Direct Load Control.
• The thermostat has a built-in time delay on cooling to protect the compressor.
Allow five to ten minutes after changing the setting before the air conditioner
starts.
• If the temperature setting is lower than the current temperature and COOL is
displayed, move the system switch from COOL to OFF for ten minutes. After ten
minutes, return the switch to the COOL position. If the air conditioner comes on,
the compressor could have reached its high limit temperature protection and
shut down. If the air conditioner does not come on after ten minutes and COOL
is displayed, troubleshoot the cooling system.
• Press the Present Setting key to check the current temperature setting.
• If desired, change the temperature setting. See User's Guide.
• If homeowner subscribes to Time-of-Use Pricing, you might need to adjust the
offset temperatures to provide a more comfortable temperature.
• Allow time for the furnace or heat pump to heat up and the fan to come on before
checking for heat at the register.
• Be aware that it is normal for the current setting and display temperature to differ
occasionally.
• During recovery from setback or setup, setting and display temperatures can
differ for up to 3o minutes after recovery period.
• The thermostat is factory-calibrated, and cannot be adjusted.
• The homeowner is a subscriber to one of the special pricing programs and the
thermostat has lost communication with the utility company. For information call
the number displayed. If the thermostat is being used as a standalone device to
disable the flashing CALL message
• Check setting in Per Hour Cycles configuration item; see Table 2.
• Check the wiring hole in the wall behind the wallplate. Plug with insulation to
prevent drafts that can adversely affect the thermostat operation.
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