Lennox G27M Series Unit Information

Page 6
SureLight CONTROL BOARD
FIGURE 2
FIGURE 3
SureLight IGNITOR
TABLE 2
SureLight BOARD J156 (J2) TERMINAL
DESIGNATIONS
PIN # FUNCTION
1 Ignitor
2
Not Used
3
Ignitor Neutral
4
Combustion Air Blower Line Voltage
5
Not Used
6
Combustion Air Blower Neutral
TABLE 3
SureLight BOARD J58 (J1) TERMINAL
DESIGNATIONS
PIN # FUNCTION
1 Primary Limit In
2
Not Used
3
Roll Out Switch Out
4
Gas Valve 24V
5
Pressure Switch In
6
Primary Limit Out
7
Not Used
8
Roll Out Switch In
9
Ground
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The fan on time of 45 seconds is not adjustable. Fan off
time (time that the blower operates after the heat de-
mand has been satisfied) can be adjusted by flipping
the dip switches located on the SureLight integrated
control. The unit is shipped with a factory fan offsetting
of 90seconds. Fan off timewill affect comfort and is ad-
justable to satisfy individual applications. See figure 4.
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FAN-OFF TIME ADJUSTMENT
To adjust fan--off timing , flip dip switch to desired setting.
60sec. 90sec. 120sec. 180sec.
4-- Two--Stage Control (A86)
All G27M units are equipped with a two--stage control
board. The two--stage board acts as a go between from
the indoor thermostat to the SureLight ignition board.
The board can be utilized in three modes: with a
SINGLE--STAGE thermostat, a TWO--STAGE thermo-
stat or with a second--stage (high fire) delay called W2
TIMED. The two--stageboard is equipped with a jumper
(see figure 5) which changes operating modes and a
jumper which adjusts second--stage heat delay during
W2 TIMED mode. While in the single--stage thermostat
mode, the unit will always operate on second--stage
heat. The combustion air blower (B6) will operate on
high speed and indoor blower (B3) will operate on heat-
ing speed. While in the two--stage thermostat mode the
unit will operate on first--stage heat (low fire). The com-
bustion air blower (B6) and indoor blower will operate
on low speed. The unit will switch to second--stage heat
(high fire) on call from the indoor thermostat W2. While
in the W2 TIMED mode the unit will fire on first--stage
heat (low fire) with the combustion air blower (B6) and

Lennox G27M Series Specifications

General

Brand	Lennox
Model	G27M Series
Category	Furnace
Language	English