Lennox 80UHG3-75 Service Literature

Service Literature
80UHG series units are mid−efficiency gas furnaces used
for upflow or horizontal applications only, manufactured
with tubular heat exchangers formed of aluminized steel.
80UHG units are available in heating capacities of 45,000
to 120,000 Btuh and cooling applications up to 5 tons. Refer
to Engineering Handbook for proper sizing.
Units are factory equipped for use with natural gas. Kits are
available for conversion to LPG operation. 80UHG−1 model
units use electronic (direct spark) ignition. 80UHG−2 and −3
model units are equipped with the Lennox SureLight silicon
nitride ignition system. The 80UHGX unit meets the Califor
nia Nitrogen Oxides (NO
x
sonal Efficiency requirements. All units use a redundant gas
valve to assure safety shut−off as required by A.G.A. or
C.G.A. Units may be installed in upflow or horizontal posi
tion.
All specifications in this manual are subject to change. Pro
cedures outlined in this manual are presented as a recom
mendation only and do not supersede or replace local or
state codes. In the absence of local or state codes, the
guidelines and procedures outlined in this manual (except
where noted) are recommended only and do not constitute
code.

TABLE OF CONTENTS

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Blower Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
High Altitude . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . .
I Unit Components . . . . . . . . . . . . . . . . . . . . . . . . . . .
II Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
III Start Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
IV Heating System Service Checks
V Typical Operating Characteristics
VI Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . .
VII Wiring and Sequence of Operation
VIII SureLight Troubleshooting Guide
) Standards and California Sea
6−15
. . . . . . . . . . . 16−17
. . . . . . . . . . . . . .
19−20
. . . . . . . . . 21−28
. . . . . . . . . . 29−34
Corp. 9728−L12
Revised 01−2002
1
2
3−4
4
5−6
15
15
18
Page 1
80UHG
 1999 Lennox Industries Inc.
Litho U.S.A.