Troubleshooting Guide - Honeywell T8602C Chronotherm IV Manual

TROUBLESHOOTING GUIDE

If...
Display does not come on.
Temperature display does not go lower
than 45° F (7° C) or higher than 88° F
(31° C) during programming.
Temperature change occurs at the wrong
times.
Heating does not come on.
Cooling will not come on.
Too warm or too cool.
System On indicator is lit, but no heat is
coming from the registers.
Thermostat current temperature setting
does not match the display temperature
within ± 1°.
bAtLo remains on display after batteries
are installed.
NOTICE
This equipment is a Class B digital apparatus, which complies with Canadian Radio Interference Regulations, CRC
c.1374.
ELECTRONIC PROGRAMMABLE THERMOSTATS
T h e n .
• Set the System switch to Off. Remove batteries. Insert batteries
backward for at least five seconds to reset thermostat. Correctly replace
batteries. Display should come on.
• Make sure batteries are fresh and installed correctly.
• The temperature setting limit is reached. 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.
• Check that System switch on thermostat is set to Heat. Allow a minimum
of five minutes for time guard protection to expire.
• Check the system fuse or circuit breaker and replace or reset if
necessary.
• Check for correct wiring and good connections.
• Disconnect and jumper wires R and W. If heat does not come on, check
the heating system.
• If display is blank or says "bAt Lo," install fresh batteries.
• Check that System switch on thermostat is set to Cool. Allow a minimum
of five minutes for time guard protection to expire.
• Check the system fuse or circuit breaker and replace or reset if
necessary.
• Check for correct wiring and good connections.
• Disconnect and jumper wires R and Y If cooling does not come on, check
the cooling system.
• If display is blank or says "bAt Lo," install fresh batteries.
• The thermostat has a built-in time delay on cooling. Allow at least five
minutes after changing the setting before the air conditioner starts.
• Make sure outdoor disconnect is engaged (on).
• If temperature setting is lower than current temperature, and System On
indicator is lit, move System switch from Cool to Off for ten minutes. After
ten minutes, return System switch to Cool position. If air conditioner
comes on, compressor could have reached its high limit temperature
protection and shut down.
• If 2- or 4-wire installation, verify that R-Rc jumper is installed
• Press Run Program key to check the current temperature setting.
• If desired, change the temperature setting. See the Owner's Guide.
• Allow time for the furnace to heat up and the fan to come on before
checking for heat at the register. (Check to make sure the Cycle Rate in
the Installation section is correct.)
• Check that the wiring hole in the wall behind the wallplate was plugged
with insulation to prevent drafts that could adversely affect thermostat
operation.
• Be aware that it is normal for the current setting and display temperature
to differ on occasion.
• During recovery from setback or setup, setting and display temperatures
can differ for up to 30 minutes after recovery period.
• Remove batteries. Wait one hour. Install fresh Alkaline batteries.
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