Lennox G61MP series Unit Information

Service Literature
G61MP series units are high−efficiency multi−position (up-
flow, downflow, horizontal right and left) gas furnaces
manufactured with Lennox Duralok Plust heat exchang-
ers formed of aluminized steel. G61MP units are available
in heating capacities of 44,000 to 132,000 Btuh (13.0.0 to
38.6 kW) and cooling applications from 2 to 5 tons (7.0 kW
to 17.5 kW)) 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. G61MP model
units are equipped with the Two−Stage Integrated SureLight
control. All G61MP units meet the California Nitrogen Ox-
ides (NO ) Standards and California Seasonal Efficiency re-
x
quirements. All units use a redundant gas valve to assure
safety shut−off as required by C.S.A.
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 recommendations only and do not consti-
tute code.

TABLE OF CONTENTS

Introduction

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Blower Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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 Field Wiring and Jumper Setting
IX Control Board Troubleshooting
Corp. 0308−L6
Revised 10−2004
G61MP SERIES UNITS
1
2
4
7
8
16
30
. . . . . . . . . . . . . . 31
. . . . . . . . . . . . . . 34
35
. . . . . . . . . . . . 38
. . . . . . . . . . . . . 46
. . . . . . . . . . . . . . . . 48
Page 1
IMPORTANT
Improper installation, adjustment, alteration, service
or maintenance can cause property damage, person-
al injury or loss of life. Installation and service must
be performed by a qualified installer, service agency
or the gas supplier.
WARNING
Electric shock hazard. Can cause injury
or death. Before attempting to perform
any service or maintenance, turn the
electrical power to unit OFF at discon-
nect switch(es). Unit may have multiple
power supplies.
WARNING
Sharp edges.
Be careful when servicing unit to avoid sharp edges
which may result in personal injury.
G61MP
© 2003 Lennox Industries Inc.