T87F ZONE THERMOSTAT AND 137421N,P WALLPLATES; T87F ZONE THERMOSTAT AND Q539A,B SUBBASES
USE 137421 WALLPLATE FOR HEAT ONLY APPLICATIONS.
SEE TABLE 1 APPLICATION INFORMATION.
Fig. 3. Mounting T87F Thermostat and 137421
Wallplate or Q539 Subbase.
An incorrectly leveled thermostat causes the
temperature control to deviate from setpoint.
7. Level the thermostat wallplate or subbase exactly
using a spirit level as shown in Fig. 4.
Do not overtighten thermostat captive mounting
screws because damage to subbase threads
8. Tighten mounting screws.
1. Before mounting the thermostat, see Heat Antici-
pator Adjustment in Settings and Adjustments sec-
2. Align the thermostat over the wallplate or subbase
and tighten the three mounting screws.
Fig. 4. Leveling wallplate or subbase before
Settings and Adjustments
To select the desired temperature for each zone, turn the
transparent dial on the zone thermostat until the desired
point on the setting scale (top scale) is aligned with the
System and Fan Switching
The Q539A provides System and Fan switches to control
heating-cooling equipment and zone one fan in multi-
• The System switch controls the system operation:
— Heat: Only the heating system operates.
— Off: Both heating and cooling control systems are
— Cool: Only the cooling system operates.
• The Fan switch controls the fan operation:
— Auto: The fan operates in response to the plenum
fan control in heating; the fan operates in
response to the thermostat in cooling.
— On: The fan runs continuously.
• To change positions, use thumb and index fingers to
move the switch lever to the desired position. Place
the switch lever directly over the selected function