Installation Guide

ATTENTION INSTALLING PERSONNEL:
As a professional installer you have an obligation to know the
product better than the customer. This includes all safety
precautions and related items.
Prior to actual installation, thoroughly familiarize yourself with
this Instruction Manual. Pay special attention to all safety
warnings. Often during installation or repair it is possible to
place yourself in a position which is more hazardous than
when the unit is in operation.
Remember, it is your responsibility to install the product safely
and to know it well enough to be able to instruct a customer in
its safe use.
Safety is a matter of common sense...a matter of thinking
before acting. Most dealers have a list of specific good safety
practices...follow them.
The precautions listed in this Installation Manual are intended
as supplemental to existing practices. However, if there is a
direct conflict between existing practices and the content of
this manual, the precautions listed here take precedence.
RECOGNIZE THIS SYMBOL
AS A SAFETY PRECAUTION
DESCRIPTION
This kit contains the appropriate burner orifices, and/or
pressure switch for the application of 80% furnaces (2-stage
commuinicating not included) in installations above their
maximum (as shipped) rated altitudes. This kit is not applicable
in Canada. Kit applies as shown in Table 1.
Natural
Gas
Orifices
Pressure
Switch
Natural
Gas
Orifices
Pressure
Switch
Natural
Gas
Orifices
ID Blwr
Pressure
Switch
No
Change
No
Change
No
Change
B1370142 #46 B1370142
0 - 4,500 Feet
(Standard Altitude)
4,501 - 7,500 Feet Above 7,500 Feet
"Standard" and "High Altitude" Kits
Table 1
A different pressure switch must be used above the rated
altitude of 4,500 feet. A high altitude pressure switch is
HANG20
HIGH ALTITUDE CONVERSION KIT
INSTALLATION INSTRUCTIONS
necessary as a result of the reduction in air density and is
required regardless of the Btu content of the fuel used.
Above an altitude of 7,500 feet, a derating of the appliance
must be followed since the CFM moved by the induced draft
blower remains almost constant while the pounds of oxygen in
that air is reduced as altitude increases. If this procedure is
not followed and the fuel input is not reduced the resulting
combustion can be inefficient, incomplete, or possibly cause
premature heat exchanger failure due to excessive tempera-
ture rise. The burner orifices in the high altitude kits have been
selected as a result of agency certified testing at high altitude
and will provide the appropriate derating. Orifice selection is
based on non-derated gas [at standard conditions of 29.92 in
Hg and 60°F—approximately 1,000 Btu/ft
3
for natural gas and
2,500 Btu/ft
3
for propane]. NOTE: “Point of use” Btu
content will be less due to decreased atmospheric pres-
sure. If the Btu content of your gas supply has been artificially
changed to account for altitude, contact your gas supplier for
orifice sizing.
Do not derate by adjusting the manifold pressure to a
lower pressure setting than specified on the furnace
nameplate. A lower air density in combination with a lower
manifold pressure at the burner orifice will prevent the orifice
from aspirating the proper amount of air into the burner
required for complete combustion.
INDEX
ATTENTION INSTALLING PERSONNEL ...........................1
DESCRIPTION ..................................................................1
GENERAL INFORMATION................................................2
HANG20 ...........................................................................2
Orifice Installation .........................................................2
Burner Orifice Replacement .......................................... 2
Gas Manifold Re-Installation ......................................... 2
ADJUSTMENTS AND CHECKS - HANG20 ....................... 2
Orifice Leak Check .......................................................3
Manifold Pressure Check ..............................................3
HANG20 ...........................................................................4
PRESSURE SWITCH REMOVAL/REPLACEMENT ..........4
IOG-7002A
September 2013