T8424D ELECTRONIC MULTISTAGE THERMOSTAT
5
69-1386-1
3.
Press the
▲
key. Factory information is displayed.
A typical example is shown, but information dis-
played varies by model. This information is for fac-
tory use only.
4.
Press the
▲
key again to display °C or °F.
5.
Press the
▼
key to change the °C or °F indication.
NOTE: Steps 6-9 apply only to T8424 Thermostats.
6.
Press
▲
to display number of cooling stages.
7.
Press
▼
to change number of cooling stages.
8.
Press
▲
to display number of heat stages.
9.
Press
▼
to change number of heat stages.
10.
Press the
▲
key to display the heat cycle rate of 1,
3, 4, 5, 6, 9, or 12. (If the T8424 is set for two heat
stages, both stages operate at the selected cycle
rate.) If the desired cycle is displayed, press the
▲
key to exit the installer setup mode. To change the
heat cycle rate, press the
▼
key to scroll between
1, 3, 4, 5, 6, 9, or 12. Stop scrolling when the
desired rate is displayed. See Table 1 for the cycle
rate options and the corresponding system equip-
ment.
11.
Press the
▲
key to display algorithm configuration
default.
12.
Press the
▲
key again to change algorithm to C1
or C3.
C1 = Standard algorithm.
C3 = Aggressive algorithm (can cause
overshooting).
13.
Press the
▲
key again. Current configuration (CC)
is displayed. A typical example is shown, but CC
varies by model. (This information is for factory use
only.)
Table 1. Heating Cycle Rates for Stage-Two Heating.
a
High efficiency furnace.
b
Refer to equipment manufacturer’s instructions.
14.
Press the
▲
key to save all changes, exit installer
setup mode and return to normal operation.
NOTE: After exiting installer setup mode, change the
setpoint to the desired room temperature.
CHECKOUT
Heating
1.
Slide the SYSTEM switch to Heat and the FAN
switch to Auto.
2.
Press and hold the
▲
key to raise the temperature
setting several degrees above the room tempera-
ture. After approximately ten seconds, the heating
equipment should start. In conventional systems,
the system turns on the fan through the use of a
time delay relay or through a limit control. When
using an electric heat thermostat, the fan starts
immediately.
3.
Press the
▼
key to lower the temperature setting
below the room temperature. Heating equipment
should stop.
M14687
M14688
M14689
M20208
M20207
M20209
M20210
M18500
System
Cycles Per Hour
Steam, gravity
1
Hydronic heat, condensing gas
furnace
a
3
Special applications
b
4,5
Gas or oil forced air (default)
6
Electric heat
9
Special applications
b
12
M18419
M18420