268894-UIM-A-0407
EFFICIENCY
RATING
CERTIFIED
ISO 9001
Certified Quality
Management System
HIGH EFFICIENCY
TUBULAR HEAT EXCHANGER SERIES
MODELS: GY8S*DH / GM8S*DH / LY8S*DH / LM8S*DH
(Single Stage Downflow / Horizontal / Low NOx)
40 - 130 MBH INPUT
(11.72 - 38.10 KW) INPUT
INSTALLATION MANUAL
SECTION I: SAFETY
This is a safety alert symbol. When you see this symbol on
labels or in manuals, be alert to the potential for personal
injury.
Understand and pay particular attention to the signal words
DANGER
,
WARNING
, or
CAUTION
.
DANGER
indicates an
imminently
hazardous situation, which, if not
avoided,
will result in death or serious injury
.
WARNING
indicates a
potentially
hazardous situation, which, if not
avoided,
could result in death or serious injury
.
CAUTION
indicates a potentially hazardous situation, which, if not
avoided
may result in minor or moderate injury.
It is also used to
alert against unsafe practices and hazards involving only property dam-
age.
Improper installation may create a condition where the operation of
the product could cause personal injury or property damage.
Improper installation, adjustment, alteration, service or mainte-
nance can cause injury or property damage. Refer to this manual
for assistance or for additional information, consult a qualified con-
tractor, installer or service agency.
This product must be installed in strict compliance with the installa-
tion instructions and any applicable local, state, and national codes
including, but not limited to building, electrical, and mechanical
codes.
LIST OF SECTIONS
SAFETY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
DUCTWORK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
FILTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
GAS PIPING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
ELECTRICAL POWER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
TWINNING AND STAGING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
VENT SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
SAFETY CONTROLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
START-UP AND ADJUSTMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . .20
WIRING DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
LIST OF FIGURES
Combustible Floor Base Accessory . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Typical Attic Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Typical Suspended Furnace / Crawl Space Installation . . . . . . . . . . . . 7
Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Gas Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Downflow Gas Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Horizontal Gas Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Electrical Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Thermostat Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Accessory Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Typical Twinned Furnace Application . . . . . . . . . . . . . . . . . . . . . . . . 12
Single Stage Twinning Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . 13
Two-Stage Twinning Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . . . 13
Vent Termination 10 ft. (3.0 m) or less . . . . . . . . . . . . . . . . . . . . . . . . 14
Vent Termination more than 10 ft. (3.0 m) . . . . . . . . . . . . . . . . . . . . . 14
Vent Termination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Typical Sidewall Vent Application . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Typical Sidewall Vent and Termination Configuration . . . . . . . . . . . .15
Home Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Combustion Airflow Path Through The Furnace Casing . . . . . . . . . .17
Alternate Air Intake, Air Outlet and Chimney Connections . . . . . . . . .17
Air Inlet, Outlet and Chimney Connections . . . . . . . . . . . . . . . . . . . . .17
Typical Chimney Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
Horizontal Air Inlet, Outlet and Chimney Connections . . . . . . . . . . . .18
Outside and Ambient Combustion Air . . . . . . . . . . . . . . . . . . . . . . . . .18
Pressure Switch Tubing Routing . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Gas Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Reading Gas Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Furnace Control Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
LIST OF TABLES
Unit Clearances to Combustibles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Minimum Duct Sizing For Proper Airflow . . . . . . . . . . . . . . . . . . . . . . . 5
Round Duct Size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Cabinet and Duct Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Recommended Filter Sizes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Nominal Manifold Pressure - High Fire . . . . . . . . . . . . . . . . . . . . . . . . 9
Ratings & Physical / Electrical Data . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Roof Pitch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Estimated Free Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
Unconfined Space Minimum Area in Square Inch . . . . . . . . . . . . . . .18
Free Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
Inlet Gas Pressure Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Nominal Manifold Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Filter Performance - Pressure Drop Inches W.C. and (kPa) . . . . . . . .24
Blower Performance CFM - (without filter) . . . . . . . . . . . . . . . . . . . . .25
Field Installed Accessories - Non Electrical . . . . . . . . . . . . . . . . . . . .26
