24
Figure 20. Gas Valve
(Honeywell shown)
(White Rodgers shown)
(4) QUICK DISCONNECT TERMINALS
1ST STAGE
REGULATOR COVER
REGULATOR ADJUST
BENEATH THIS SCREW
VENT (.330 DIA.
+DFT. POST)
ACCEPTS 5/16” HOSE
CONNECTION
2ND STAGE
REGULATOR COVER
REGULATOR ADJUST
BENEATH THIS SCREW
OUTLET PRESSURE
POST SET SCREW: 3/32”
HEX HEAD (.339 DIA. +DFT.)
ACCEPTS 5/18” HOSE CONNECTION
CONTROL
LABEL
INLET PRESSURE POST
SET SCREW: 3/32” HEX HEAD
(.339 DIA. +DFT.)
ACCEPTS 5/18”
HOSE CONNECTION
VENT FITTING FOR 90 PLUS
EFFICIENT APPLIANCES
LOW STAGE ADJUSTMENT
UNDER VENT CAP
HIGH STAGE ADJUSTMENT
UNDER VENT CAP
OUTLET PRESSURE TAP
1/8 NPT
INLET PRESSURE TAP
1/8 NPT
2-STAGE
OPERATOR
altitude is detailed in the installation instructions
provided with the conversion kit. Approved
conversion kits are listed below.
United States LP/Propane Gas Sea Level and
High Altitude Conversion Kit - P/N 904404
This kit is for LP/propane conversion in the
United States at altitudes between zero and
10,000 ft. above sea level. Follow the installation
instructions supplied with the kit for proper
installation.
Canadian LP/Propane Gas Sea Level and High
Altitude Conversion Kit - P/N 904405
This kit is for LP/propane conversions in Canada
at altitudes between zero and 4500 ft. above sea
level. Follow the installation instructions supplied
with the kit for proper installation.
IMPORTANT NOTE: When converting a low
NOx furnace from Natural Gas to LP/Propane
Gas, it is necessary to remove the NOx baffl es
from the furnace.
HIGH ALTITUDE CONVERSION
High Altitude Application
Conversion of this furnace to replace the
pressure switch or to utilize LP/propane gas
must be made by qualifi ed service personnel,
using factory authorized or approved parts. High
altitude applications with this furnace can be fi eld
performed by a simple adjustment of manifold
pressure, and if necessary changing the orifi ces
and the vent pressure switch. The changes
required depend on the installation altitude and
the heating value of the gas. The gas heating
value based on sea level can be obtained from
your local gas utility. The heating value of gas at
high altitude is always lower than the sea level
heating value. The heating values used in Tables
10 and 11 are based on sea level values.
Pressure Switch Conversion for
High Altitude Applications
These units are factory equipped to operate
between zero and 8000 feet above sea level.
For higher altitude applications, you may need
to replace the vent pressure switch in addition
to the main gas burner orifi ces.
Natural Gas High Altitude
Conversion
All factory shipped furnaces are ready to operate
between zero and 4999 ft. above sea level. For
higher altitudes (between 5000 and 10,000 ft.
above sea level), conversion can be achieved
simply by adjusting the furnace manifold pressure
as shown in Tables 6 and 7.
LP/Propane Gas Sea Level and
High Altitude Conversion
Conversion to LP/propane gas can be
accomplished by fi rst replacing the natural gas
orifi ces with the appropriate LP/propane orifi ces
shown in Table 8 or 9 Note: for installations
between zero and 5000 ft. above sea level, refer to
Table 8. For installations above 5000 ft. above sea
level, refer to Table 9. After changing the orifi ces,
use Tables 7 and 9 to determine the appropriate
manifold pressure for your installation.
Conversion to LP/propane, sea level, and high
