Installation Sheet
Rinnai Corporation EX38C Manual 29
Adjust Gas Pressure Settings
Normal Operating Sequence
When you press the ON/OFF button, the LED display
will illuminate, the combustion fan will begin to run,
and the spark will ignite the main burner.
This heater has an automatic ignition system. When
the main burner has lit, the combustion lamp will glow
red, and the spark will stop.
7. Press the SW1 switch twice to enter the gas code
into memory.
8. Press the ON/OFF button to operate the
appliance.
9. Press the SW1 switch. The LED will display a “7”.
10. Press the SW1 switch again to change to the low
pressure mode. The LED will display “PL”.
11. Compare the pressure reading on the manometer
to the correct table for your gas type. If necessary
adjust the low fire pressure using the ▲ and ▼
buttons. Press the SW1 switch again.
12. The LED will display “PH” indicating high fire
mode.
13. Compare the pressure reading on the manometer
to the correct table for your gas type. If necessary
adjust the high fire pressure using the ▲ and ▼
buttons.
14. Press the ON/OFF button again. The LED display
turns blank and the appliance returns to the
normal OFF mode.
15. Remove manometer and install Allen head
screws. Operate the unit and
16. Return unit to normal functioning.
17. Reactivate “Set Back” feature.
check the normal operating sequence
visually inspect the flame
check for gas leaks at the test points
1. Install the front panel and bottom cover.
2. Place the conversion plate (label) on the front
cover.
Final Assembly
The LED display turns blank and the unit
returns to the normal off mode. You are now
ready to program in your correct low fire and
high fire gas pressure setting. Follow the
procedure below for setting the manifold gas
pressure. Do not adjust gas pressure on this
appliance using the screw on top of the gas
valve.
Visual Inspection of Flame
Check that the burner flames are operating normally.
The flame can be seen through the circular window.
When operating normally the burner flame should
appear as long, clear, blue, stable, streaks. Yellow
flames or an orange color is abnormal and
maintenance is required.
NORMAL
Flame Rod
Long, clear, blue,
stable flames
ABNORMAL
Yellow flames or
orange color
Flame Rod
NOTE: If the LED display shows “HF” or “LF” do not
touch the ▲ and ▼ buttons or Economy button.
In this case push SW1.