Honeywell T8112 User Manual

T8112 PROGRAMMABLE THERMOSTAT
68-0170
8
Helping You Control Your World
Home and Building Control
Honeywell Limited-Honeywell Limitée
155 Gordon Baker Road
North York, Ontario
M2H 2C9
68-0170 1-96 Printed in U.S.A.
Fan Switch
FAN AUTO: Normal setting for most homes. A
single-speed fan turns on automatically with
the air conditioner or furnace. A two-speed fan
usually runs on high with the air conditioner
and on low with the furnace.
FAN ON: The fan runs continuously. Use for
improved air circulation during special
occasions or for more efficient electronic air
cleaning.
System Switch
COOL: The thermostat controls the air
conditioning system.
OFF: Both the heating and air conditioning
systems are off.
HEAT: The thermostat controls the heating
system.
Auto On
M1705
Auto On
M1706
HeatCool Off
M1704
HeatCool Off
M1707
HeatCool Off
M1703
TROUBLESHOOTING
Home and Building Control
Honeywell Inc.
1985 Douglas Drive North
Golden Valley, MN 55422
Printed on recycled paper containing at
least 10% post-consumer paper fibers.
IF… THEN…
Display will not come on. • Set the system switch to OFF; remove batteries; insert backward for at least
five seconds to reset thermostat; replace batteries correctly. Display should come
on.
• Make sure batteries are fresh and installed correctly.
Temperature display will not go lower
than 45°F (7°C) or higher than 88°F
(31°C) during programming.
• The temperature setting limit has been reached. The setting range is 45°F to 88°F
(7°C to 31°C).
Heating will not come on. • If the display is blank or displays bAt Lo , install fresh batteries.
• Check that the switch on the thermostat is set to HEAT.
• Check the system fuse or circuit breaker and replace or reset if necessary.
• If the temperature setting is higher than the current temperature, and SYSTEM ON
indicator is lit, see the furnace manufacturer instructions.
Cooling will not come on. • If the display is blank or displays bAt Lo , install fresh batteries.
• In 2- or 4-wire installations, verify that the R-Rc jumper is installed.
• Check that the switch on the thermostat is set to COOL.
• Check the system fuse or circuit breaker and replace or reset if necessary.
• The thermostat has a built-in time delay on cooling. 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 the SYSTEM
ON indicator is lit, 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 the
SYSTEM ON indicator is lit, see the air conditioner manufacturer instructions.
SYSTEM ON indicator is lit, but no
heat is coming from the registers.
• 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 system on-time is set correctly according
to the instructions in the Installation section.
Furnace or air conditioner cycles too
frequently.
• Check the system setting on the back of thermostat.
The system on-time is too short or too
long.
• Readjust according to the instructions in the Installation Section.
The thermostat current setting does
not match the display temperature.
• Check that the wiring hole in the wall behind the wallplate was plugged with
insulation to prevent drafts that could adversely affect thermostat operation.
• It is normal for the current setting and display temperature to differ occasionally.
bAt Lo remains on the display after
fresh batteries have been installed.
• Remove batteries. Wait one hour. Install fresh alkaline batteries.

Honeywell T8112 Specifications

General

Brand	Honeywell
Model	T8112
Category	Thermostat
Language	English