Rinnai EX38DT Installation And Operation Manual page 27

8. Press the Test Switch twice to enter the
gas code into memory.
The LED display turns blank and the unit
returns to the normal off mode. You are
now ready to program 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 furnace using the
screw on top of the gas valve.
9. Press the ON/OFF button to operate the
furnace.
10. Press the Test Switch twice to change to
the low pressure mode. The LED will
display "PL".
11. Compare the pressure reading on the
manometer to the desired manifold test
pressure (low) for your gas type, altitude
and vent length. If necessary adjust the low
fire pressure using the ▲ and ▼ buttons.
12. Press the Test Switch. The LED will display
"PH" indicating high fire mode.
13. Compare the pressure reading on the
manometer to the desired manifold test
pressure (high) for your gas type, altitude
and vent length. 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 furnace returns
to the normal OFF mode.
15. Remove manometer and two barb fittings,
and install Allen head screws. Operate the
unit and follow steps A, B, and C below.
A. Check for Gas Leaks at the Test
Points.
EX38DT Installation and Operation Manual
B. Check the 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 furnace has an automatic
ignition system. When the main
burner has lit, the combustion lamp
will glow red, and the spark will stop.
C. Visually Inspect the 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
Flame Rod
Yellow or
orange flames
Figure 34: Normal and Abnormal Flames
16. Install the front panel.
17. If doing a gas type conversion, place the
new conversion rating plate (label) on the
front cover.
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