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Figure 15 shows the various fan “off” timings and how
jumper should be positioned. Unit is shipped with a
factory fan “off” setting of 90 seconds. Fan “off” time
will affect comfort and efficiency and is adjustable to
satisfy individual applications.
IMPORTANT
Potential for improper operation.
If fan “OFF” timing is set too low, residual heat in
heat exchanger may cause primary limit S10 to
trip resulting in frequent cycling of blower. If this
occurs, adjust blower to longer time setting.
150 SECOND FAN OFF TIME
90
270
150
210
90
150
270
210
90
270
150
210
90
270
150
210
90
270
150
210
JUMPER
JUMPER
JUMPER
JUMPER
NO JUMPER
90 SECOND FAN OFF TIME
210 SECOND FAN OFF TIME
270 SECOND FAN OFF TIME
330 SECOND FAN OFF TIME
FIGURE 15
FAN OFF TIME ADJUSTMENT
VII – MAINTENANCE
At the beginning of each heating season, the system
should be checked as follows:
A – Filters
G20RE and G20RXE series units are equipped with per-
manent internal filters which should be inspected
monthly and cleaned when necessary to assure proper
furnace operation. Use the following procedure to
clean filter. Refer to figure 16.
To Inspect/Clean Filters:
1 – Turn off electric power to furnace.
2 – Remove upper access panel and filter access door.
See figure 1.
3 – Lift left side filter over left support angle. For easy
handling, hold filter at center bottom.
4 – Rotate filter sideways and pull it through the blow-
er access panel opening.
5 – Pull the second filter out the same way as the first.
6 – Wash filters with warm water and mild detergent.
When dry, filters should be sprayed with filter han-
dicoater before replacing. Filter Handicoater is RP
products coating no. 418 and is available as Len-
nox part no. P–8–5069.
7 – Right filter should rest under tab of right filter sup-
port angle.
8 – Left filter must rest against top edge of right filter.
B – Supply Air Blower
1 – Check and clean blower wheel.
2 – Motors used on G20RE series units are permanent-
ly lubricated and need no further lubrication.
C – Flue and Chimney
Check flue pipe, chimney and all connections for tight-
ness and to make sure there is no blockage or leaks.
D – Cleaning Heat Exchanger and Burners
NOTE–Use papers or protective covering in front of
furnace while cleaning furnace.
–150 UNITS
BLOWER
RIGHT FILTER
LEFT FILTER
LEFT SUPPORT ANGLE
RIGHT FILTER SUPPORT ANGLE
(ON THREE SIDES)
–150 UNITS MAKE SURE FILTER
IS PLACED INTO THIS CHANNEL
ROTATE FILTER TO REMOVE
TAB
FILTER ARRANGEMENT
INCORRECT (LEFT FILTER BELOW
RIGHT FILTER)
FIGURE 16
