Installation Sheet

28 Rinnai Corporation EX38C Manual
Complete these instructions for altitude and vent length. (Default altitude: 0ft - 2,000ft. Default vent length: 0 - 7ft+1 elbow )
For high altitude installations in Canada, the conversion shall be carried out by a manufacturer’s authorized
representative, in accordance with the requirements of the manufacturer, provincial or territorial authorities having
jurisdiction and in accordance with the requirements of CAN/CGA-B149.1 or CAN/CGA-B149 installation codes.
Adjust Gas Pressure Settings
1. Turn off the gas and the power supply.
2. Remove test port screws (1/8 NPT tap) with 3/16
Allen wrench located at gas valve and burner cover.
Attach dual port manometer to these test ports as
shown. Ensure that the manometer is properly
calibrated.
3. Turn on the gas and power supply to the appliance.
4. Ensure “Set Back” feature has been deactivated.
(“Set Back” feature is active by default.)
5. With the unit in the Off position, press the SW1 switch
at the top of PC board until it beeps.
6. Select the correct code for gas type, altitude, and vent
length on the LED display using ▲ and ▼ buttons:
CAUTION
Do not touch any other areas on the PC board
besides the “SW” switches while power is supplied to
the appliance. Parts of the PC board are supplied
with 120 volts AC.
CAUTION
Do not touch the areas at or near the exhaust. This
area becomes very hot and could cause burns.
CAUTION
Do not insert hands or objects into the circulation fans
while they are running. Injury or mechanical
malfunction may occur.
The regulator has been factory pre-set. If the
pressure is incorrect, check the supply pressure first,
before making any adjustments to the appliance.
Also, if the low control pressure cannot be obtained,
adjust the adjustment screw on the proportional valve
to roughly set pressure and then recheck both the low
and high fire pressures.
NOTICE
Natural Gas
Short Vent Lengths: 0 - 7ft+1 elbow
(A1 - A4)
Long Vent lengths: 7ft +1 elbow - 13ft + 2 elbows
(A5 - A8)
Propane Gas
Short Vent Lengths: 0 - 7ft+1 elbow
(L1 - L4)
Long Vent lengths: 7ft +1 elbow - 13ft + 2 elbows
(L5 - L8)
Code
A1 / A5 A2 / A6 A3 / A7 A4 / A8 L1 / L5 L2 / L6 L3 / L7 L4 / L8
Altitude
0-2000 ft 2001-5200 ft 5201-7700 ft 7701-10200 ft 0-2000 ft 2001-5200 ft 5201-7700 ft 7701-10200 ft
Manifold test
pressure -
W.C. Low
1.69 in
(43 mm)
1.59 in
(40 mm)
1.49 in
(38 mm)
1.43 in
(36 mm)
3.21 in
(82 mm)
3.01 in
(76 mm)
2.85 in
(72 mm)
2.73 in
(69 mm)
Manifold test
pressure -
W.C. High
3.77 in
(96 mm)
2.99 in
(76 mm)
2.69 in
(68 mm)
2.45 in
(62 mm)
6.38 in
(162 mm)
5.62 in
(143 mm)
5.06 in
(129 mm)
4.58 in
(116 mm)
PCB Test Switch
Positive Port
Negative Port