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CAUTION
Some soaps used for leak detection are corrosive to
certain metals. Carefully rinse piping thoroughly af
ter leak test has been completed. Do not use
matches, candles, flame or other sources of ignition
to check for gas leaks.
23 -If a leak is detected, shut gas and electricity off and
repair leak.
24 -Repeat steps 23 and 25 until no leaks are detected.
25 -Replace access panel.
FIGURE 19
Remove 5 screws if necessary
(either side of cabinet)
1
2
3
4
5
C-Supply Air Blower
1 - Check and clean blower wheel.
2 - Motors used on the Lennox ML180UHA series units
are permanently lubricated and need no further lu
brication.
D-Flue and Chimney
Flue must conform to local codes. Flue pipe deteriorates
from the inside out and must be disconnected in order to
check thoroughly. Check flue pipe, chimney and all con
nections for tightness and to make sure there is no block
age or leaks.
E-Electrical
1 - Check all wiring for loose connections.
2 - Check for the correct voltage at the furnace (furnace
operating). Correct voltage is 10%
3 - Check amp-draw on the blower motor with inner blow
er access panel in place. See figure 20.
Motor Nameplate__________Actual__________
FIGURE 20
kVAr
kWh
COM
M
V3
V1 V2
POFF
MR
EX
−
1
W
3
2
AMP Meter
Check Motor AMP Draw
