Honeywell T8090A/191108AJ Manuel page 20

Troubleshooting (Continued)
Problem
Clock does not run.
Applicable to heating-cooling subbase only.
1
If clock is not battery powered, clock can use batteries for backup.
2
Check
— thermostat connections at the
two C terminals. If no
connections, clock needs
batteries in order to run.
Batteries may not have been
installed. 2
— Batteries may need
replacement.
— if new batteries are installed
and clock still does not run.
— voltage across the two
C terminals.
Install batteries as shown in Fig. 2.
Replace with two new AAA alkaline batteries as
shown in Fig. 2.
Replace thermostat.
Remove thermostat from the wallplate or
subbase and measure the voltage. Refer to the
Voltage at Clock Terminals table for cause and
reaction.
20
Action
Continued
69-0628B—1