Aprilaire 8353 用户手册

• Four setpoints for weekday programming—two setpoints for 

weekend comfort.

• Two “AA” ENERGIZER brand batteries retain program memory, 

even during power outages.

• Low battery indicator.

• Fahrenheit/Celsius display option.

• Programmable from 45°F (4°C) to 90°F (32°C).

• Accuracy within ± 1 degree.

• Adjustable temperature differential: 1-3 degrees.

• Maintains summer and winter programming.

• Low temperature freeze protection. While in heat mode, thermostat

will mechanically turn on heat if temperature drops to 40°F (4°C) –
even if batteries are missing or drained.

• Automatic heating shutdown if temperature exceeds 90°F (32°C).

1. Turn off power to heating and cooling system.

2. Remove cover of old thermostat to expose wires. Do not 

disconnect wires. (Fig. 1)

3. Label wires per Table 1.

M, 4, RH, R5 or R

RH

Heat Transformer,
hot side

V or RC

RC

Cooling Transformer, hot
side

Y or Y6

Y

Cooling control

H, W or 4

W

Heating control

F or G

G

Fan control relay

C*

Y or None

Either cooling control or
common side of trans-
former

*NOTE: On some older models, the C terminal can be either the cooling-
control or the common side of the transformer. Check furnace wiring 
diagram to verify C terminal. If it is the common side of the transformer,
cap the wire and tuck into the wall. If it is the cooling control, connect to
the Y terminal.

4. After labeling wires, remove wires from terminals.

5. Remove existing thermostat base from wall.

6. Refer to the following section for instructions on how to 

install thermostat.

2