Lennox EL196UHE Series Information page 16

Red and
or Red Tubing
(negative -)
To Cold End Header Box
1 - Remove thermostat demand and allow unit to
cycle off.
2 - Install a tee in the negative (-) line (red and black tubing
or red tubing) and a tee in the positive (+) line (black
tubing) running from the pressure switch to the cold
end header box.
3 - Install a manometer with hose from the negative (-)
side of the manometer to the tee installed in the
negative (-) line and with hose from the positive (+)
side of the manometer to the tee in the positive (+)
line.
NOTE - Both sides of the cold end header box are
negative. How
sure than the (-) port.
1
ON
Pre -Purge
OFF
DEMAND
CAI
IGNITOR
GAS VALVE
INDOOR BLOWER
*Blower on time will be 30 seconds after flame is sensed. Blower off time will depend on "OFF TIME" Setting.
Measuring Pressure Differential
Black Tubing
Field Provided Tubing
ELECTRONIC IGNITION
15
Ignitor Warm-up
To Pressure Switch
"+"
High
"-"
Low
4 - Operate unit and observe manometer reading.
Readings will change as heat exchanger warms.
a. Take one reading immediately after start up.
b. Take a second reading after unit has reached
steady state (approximately 5 minutes). This will be
the pressure differential.
The pressure differential should be greater
than those listed in table 7.
5 - Remove thermostat demand and allow to cycle off.
6 - Remove manometer and tee's. Reinstall combustion
air sensing hoses to the pressure switch.
FIGURE 12
34
38
Trial for
Blower "On"*
Ignition
FIGURE 13
Page 16
Black Tubing
(positive +)
To Cold End Header Box
80
Delay
5 SEC
Post
Purge