NG to LP Conversion Guide

Form CP-UD-GC, P/N 197209R11, page 6
FIGURE 4 - Top View of Valves identifying Pressure Taps and Adjustment Screw Location
4) Measuring Single Stage or Two Stage High Fire - Turn the knob or switch
on the top of the valve to “ON”. Remove the cap from the pressure adjusting
screw and adjust the manifold pressure to the pressure selected from TABLE
2. Adjust pressure by turning the regulator screw IN (clockwise) to increase
pressure or OUT (counterclockwise) to decrease pressure.
Measuring Two Stage Low Fire - Disconnect the wire from the “HI” terminal
on the gas valve and check the low re pressure. Turn the regulator screw
to adjust the low re outlet pressure to the “Low Fire” pressure selected from
TABLE 2. Re-connect the wire to the gas valve.
CAUTION
DO NOT bottom out the gas valve regulator adjusting screw.
This can result in unregulated manifold pressure causing
excessoverreandheatexchangerfailure.
5) Turn up the thermostat. On Models UDAS and UDBS, depress and hold
the safety door switch. Cycle the burner once or twice to properly seat the
adjustment spring in the valve.
Re-check the pressure(s). When the outlet pressure is right for the installation,
remove the manometer and replace the cap.
Check for leakage at the pressure tap tting.
6) With the heater operating, determine that the inlet pressure to the heater is
between 5 and 13.5 inches w.c. for natural gas or between 10 and 13.5 inches
w.c. for propane gas. Take this reading as close as possible to the heater. (The
gas valves have an inlet pressure tap; see FIGURE 4.) If the inlet pressure is
not within the specied range, the inlet pressure must be corrected and the
manifold (outlet) pressure re-checked.
7) If the gas valve has been adjusted for operation above 2000 ft, nd the High
Altitude Adjustment label in the kit. Using a permanent marker, ll-in the
appropriate information from TABLE 3A, page 11, for UDAP or UDAS or
TABLE 3B, page 12, for UDBP or UDBS. Select a location for the label on the
outside of the heater access panel so that it will be conspicuous to anyone
operating or servicing the unit. Be sure the surface is clean and dry and adhere
the label. (NOTE: At altitudes from 0-2000ft/0-610M, this label is not used.)
8. Check for safe and proper operation of the heater by observing operation for at
least one complete cycle. (NOTE: Models UDAS and UDBS, depress and hold
the safety door switch.)
9. Fill in the information required on the gas conversion tape. Select a location near
the rating plate. Be sure the surface is clean and dry and afx the tape to the
heater. Close the access door.
Single-Stage
Valve
(two styles)
1/8” Outlet
Pressure Tap
Adjust Outlet
Pressure
Inlet
Pressure Tap
Two-Stage Valve
Adjust High
Fire Outlet
Pressure
Adjust Low
Fire Outlet
Pressure
Inlet
Pressure
Tap
1/8” Outlet
Pressure Tap
1/8” Outlet
Pressure Tap
Inlet Pressure Tap
Adjust Outlet Pressure