Rheem Raypak Delta Limited 399B Installation & Operating Instructions Manual page 20

CAUTION: Support gas supply piping with hangers,
not by the heater or its accessories. Make sure the
gas piping is protected from physical damage and
freezing, where required.
Reversing Gas Supply Connection
Reversing the standard fuel connection from the left-
hand to the right-hand side is a simple field operation.
1. Disconnect all electrical power from the heater (if
applicable).
2. Disconnect the main gas pipe from the heater (if
applicable).
3. Remove the left and right front panels from the
heater.
4. Locate the main gas line that traverses across the
heater above the manifold risers.
5. Remove the pipe cap from the right-hand end of
the main gas line.
6. Reinstall the pipe cap on the left-hand end of the
main gas line.
7. Remove plastic cap from the right-hand side panel
and reinstall into the standard main gas opening
located on the left-hand side of the heater.
8. Remove the rubber grommet from the left-hand-
side panel and reinstall into the standard main
gas opening, located on the right-hand side of the
heater.
9. Install a coupling, nipple, union and sediment trap
onto the right-hand end of the main gas line and
then install the gas line, making sure that a manual
shut-off valve has been installed within 10 ft of the
heater.
10. Replace the left and right front panels on the heat-
er.
Gas Supply Pressure
A minimum of 5.0 in. WC and a maximum of 10.5 in.
WC upstream gas pressure is required under load
and no-load conditions for natural gas. A minimum of
11.0 in. WC and a maximum of 13.0 in. WC is required
for propane gas. The gas pressure regulator(s) sup-
plied on the heater is for low-pressure service. If
upstream pressure exceeds 14.0 in. WC, an interme-
APPROVED
diate gas pressure regulator, of the lockup type, must
be installed.
When connecting additional gas utilization equipment
to the gas piping system, the existing piping must be
checked to determine if it has adequate capacity for
the combined load.
The gas valve pressure regulator(s) on the heater
are nominally preset at 3.5 in. WC for natural gas,
and 10.5 in. WC for propane gas heater on models
302 thru 902. 9.0 in. WC for propane gas on heater
models 992 thru 2342. The pressure at the gas valve
outlet tap, measured with a manometer, while in oper-
ation should be 3.5 ± 0.1 in. WC for natural gas and
10.5 in. ± 0.1 in. WC for propane gas on heater mod-
els 302 thru 902. 9.0 to 9.5 in. WC for propane gas
on heater models 992 thru 2342. If an adjustment is
needed, remove the adjustment screw cover and turn
the adjustment screw clockwise to increase pressure
or counter-clockwise to lower pressure.
20
UNCONTROLLED DOCUMENT IF PRINTED
Models 399B–2339B
Adjustment
Models 989B–2339B
Fig. 15: Gas Valves