Installation
32
RT-SVX46G-EN
Requirements for Gas Heat
Note:
The unit gas train and optional through-the-base
gas shut-off valve are rated at 1/2 PSIG maximum.
A pressure reducing regulator is recommended to
prevent this maximum from being exceeded.
These components must be isolated during field
gas piping test that exceed 1/2 PSIG. It is
recommended that the field piping be capped prior
to the unit gas train or optional through-the-base
gas shut-off valve if present.
•
Gas supply line properly sized and connected to the
unit gas train.
•
All gas piping joints properly sealed.
•
Gas piping leak checked with a soap solution. If piping
connections to the unit are complete, do not pressurize
piping in excess of 0.50 psig or 14-inch wc to prevent
component failure.
•
Drip leg Installed in the gas piping near the unit.
•
Minimum gas supply pressure should be 4.5-inch wc.
•
Minimum gas supply pressure for modulating "V"
models should be 5.5-inch wc.
•
Maximum gas supply pressure must not exceed 14.0-
inch wc.
•
Manifold pressure for single stage heaters should be
set to 3.3-inch wc.
•
Manifold pressure for two stage heaters should be set
to 3.5-inch wc on high fire and 1.8-inch wc on low fire.
Note:
Manifold pressure not applicable for units with
Low NOx gas furnace option. Manifold pressure is
not utilized as an adjustment/checking parameter
for this system.
•
Manifold pressure for modulating heaters is 3.5-inch
wc at high fire.
Note:
Modulating valve must have 10 Vdc signal voltage
to achieve high fire. See the following image for
manifold pressure tap location.
•
Flue exhaust clear of any obstruction.
Figure 58. Typical through-the-base gas installation
90° Elbow
6 1/2” (165 MM) Pipe Nipple
Gas Shut-Off Valve
and Street Elbow
90° Elbow
and Nipples
5” (127 MM) Pipe Nipple and Union
Figure 59. Manifold pressure tap location
Modulating
Valve
Adjust Manifold
Pressure Here
Main Gas Valve
Tap Location to Obtain Manifold
Pressure for Modulating Gas Heaters
