Lennox SLP98UHV Installation Instructions Manual page 39

Operation
Variable Capacity Heat (35% to 100%)
Three-Stage Heat
(35%, 70%, 100%)
Two-Stage Heat (W1 70%, W2 100%)
NOTE - When the SLP98UHV is used with an icomfort
Touch communicating thermostat, all indoor blower speed
selections and DIP switch settings are made by the com-
municating thermostat.
SLP98UHV units are equipped with an integrated con-
trol. This control manages ignition timing, combustion air
inducer speed, heating mode fan off delays and indoor
blower speeds based on selections made using the icom-
fort Touch thermostat or the control DIP switches and on-
board links. The control includes an internal Watchguard
feature which automatically resets the ignition control
when it has been locked out.
NOTE - All DIP switches are factory shipped in the
"OFF" position.
Heating Operation DIP Switch Settings -- Figure 47
Switch 1 -- Thermostat Selection -- This unit may be
used with either a single-stage or two-stage thermostat.
The thermostat selection is made using a DIP switch
which must be properly positioned for the particular appli-
cation. The DIP switch is factory-positioned for use with a
twostage thermostat. If a single-stage thermostat is to be
used, the DIP switch must be repositioned. See table 13.
Switch 2 -- Operating Mode with Two-Stage Ther-
mostat -- If a two-stage thermostat is used, the furnace
can operate in either variable-capacity or conventional
twostage mode. When variable-capacity mode is select-
ed, the firing rate of the unit is varied to maximize comfort.
Conventional two-stage mode is the factory default set-
ting. See table 13.
Switch 3 -- Second-Stage Heat On Delay -- If a single-
stage thermostat is used, the integrated control can be
used to energize second-stage heat after either 7 minutes
or 12 minutes of first-stage heat operation. See table 13.
Switches 4 and 5 -- Blower-Off Delay -- The blower-on
delay of 30 seconds is not adjustable. The blower-off delay
(time that the blower operates after the heating demand
has been satisfied) can be adjusted by moving switches 4
TABLE 13
Thermostat Selection Switch Settings
Thermostat Switch 1
Two-Stage Off
Single-Stage On
Two-Stage Off
and 5 on the integrated control. The unit is shipped from
the factory with a blower-off delay of 90 seconds. The
blower off delay affects comfort and is adjustable to sat-
isfy individual applications. Adjust the blower off delay to
achieve a supply air temperature between 90° and 110°F
at the exact moment that the blower is de-energized. Lon-
ger off delay settings provide lower supply air tempera-
tures; shorter settings provide higher supply air tempera-
tures. Table 14 provides the blower-off timings that will
result from different switch settings.
Indoor Blower Operation DIP Switch Settings
Switches 6 and 7 -- Continuous Indoor Fan Operation
Blower Speed -- The unit is shipped from the factory with
the DIP switches positioned for medium low (2) speed
during continuous indoor blower operation. The table be-
low provides the continuous blower speeds that will result
from different switch settings. Refer to tables beginning on
page 42 for corresponding cfm values.
* Percentage of high speed cooling
Page 39
Switch 2
On
On
Off
TABLE 14
Blower-Off Delay Switch Settings
Blower-Off Delay
Switch 4
(Seconds)
60
90 (factory)
120
180
TABLE 15
Continuous Indoor Blower Operation -- Blower Speeds
Speed
1 - Low (28%)*
2 - Medium Low (38%)*
Factory
3 - Medium High (70%)*
4 - High (100%)*
Switch 3
Off
2nd stage delay OFF = 7 minutes
ON = 12 minutes 3rd stage delay
10 minutes fixed
Off
Switch 5
Off On
Off Off
On Off
On On
Switch 6 Switch 6
Off On
Off Off
On Offf
On On