Honeywell T8090A Thermostat User Manual


 
69-0750—1 6
Remove the thermostat from the wallplate or subbase.
Connect an ac ammeter of appropriate range (about 0A to
2A) between the R and W terminals on the wallplate or
subbase except for electric heat and heat pump systems.
Let the system operate for one minute.
Adjust the heat anticipator lever to match the number
that reads on the ammeter.
ATTACH THERMOSTAT COVER
Make sure the packing inserts in the thermostat base are
removed.
Place the two tabs on the upper edge of the cover into the
mounting slots in the thermostat base. See Fig. 11.
Swing the cover downward until it catches at the bottom
of the base.
Fig. 11—Attach cover.
SET TEMPERATURE CONTROL LEVERS
The two levers on top of the thermostat control the low
and high temperatures for energy savings and comfort
control. See Fig. 12. The lever on the left (blue mark)
controls the lower temperature. The lever on the right (red
mark) controls the higher temperature.
We recommend pushing the levers together at an appro-
priate temperature for either heat or cool until the occupant
programs the thermostat and makes the final temperature
selections.
Fig. 12—Temperature control levers.
SET SUBBASE SWITCHES (IF APPLICABLE)
The subbase system switch controls system operation as
follows:
HEAT: Heating system is controlled by the thermostat.
Cooling system is off.
COOL: Cooling system is controlled by the thermostat.
Heating system is off.
OFF: Both the heating and cooling systems are off. If the
fan switch is in the AUTO position, the fan is also off.
The subbase fan switch controls fan operation as follows:
ON: Fan operates continuously.
AUTO: Fan operates with the cooling equipment as
controlled by the thermostat or with the heating equip-
ment as controlled by the plenum switch. In electric
heat, heat pump and fan coil systems, the fan is
controlled by the thermostat for heating and cooling.
To switch positions, use thumb or index finger to slide
lever to the desired position. Switch lever must stop in
detent over the desired function indicator mark for proper
circuit operation.
Checkout
CAUTION
Do not check operation by shorting across termi-
nals of system controls. This will damage the heat
anticipator.
HEATING-ONLY SYSTEM
Turn on power to the furnace.
Push together both temperature setting levers at least 5° F
[3° C] above room temperature. The main burner should
come on. The fan will start when the furnace heats up.
Move both levers 5° F [3° C] below room temperature.
The burner should shut off.
Operate the entire heating system at least one complete
cycle.
If thermostat fails any test, refer to the Troubleshooting
Guide in the Owner’s Manual.
Reset both temperature setting levers to the desired tem-
peratures.
COOLING-ONLY SYSTEM
Turn on power to the cooling equipment.
Push both temperature setting levers together at least
5° F [3° C] below room temperature. The cooling equip-
ment should operate, and the fan should start. Allow for any
time delay that may be built into the compressor control
circuit.
NOTE: To avoid compressor damage, do not operate the
system when outdoor temperature is below 50° F [10° C].
Refer to manufacturer recommendations.
Move both levers 5° F [3° C] above room temperature.
The cooling equipment and the fan should shut off.
Operate the entire cooling system at least one complete
cycle.
12
6
3
9
50
60
70
80
M1519
50
60
70
80
HIGH TEMPERATURE
(RED MARK)
SET LEVER
LOW TEMPERATURE
(BLUE MARK)
SET LEVER
M859