Installation Guide

74 Rinnai Tankless Water Heater Installation and Operation Manual
* See “Electrical Diagnostics” on Technical Data
Sheet located on inside front cover of water
heater.
03
Power interruption during bath fill
(Water will not flow when power
returns)
• Turn off all hot water taps. Press
ON/ OFF twice.
1 0
Air Supply or Exhaust Blockage/
Condensate Trap is Full
• Ensure condensate line is not
blocked.
• Ensure internal air filter is clean with
no obstructions.
• Ensure High Altitude setting. (See
Parameter Settings)
• Ensure combustion air and exhaust
vents are not blocked and approved
venting materials are being used.
• Ensure vent length is within limits.
• Check fan for debris and ensure
wheel turns freely.
• Verify check valve is not stuck
between fan casing and burner
body.
1 1
No Ignition (Heater Not Turning On)
• Check that the gas is turned on at
the water heater, meter, or cylinder.
• Ensure gas line, meter, and/or
regulator is sized properly.
• If the system is propane, make sure
that gas is in the tank and the tank
is properly purged.
• Ensure gas type and inlet gas
pressure are correct.
• Bleed all air from gas lines.
• Check the ground wire for the PC
Board.
• Ensure flame rod wire is connected.
• Ensure igniter is operational.*
• Check gas solenoid valves for open
or short circuits.*
• Verify selected gas type is correct.
• Ensure condensate line is not
blocked.
To display diagnostic codes:
Turn off the water heater by pressing the “On/Off” button.
Press and hold the “On/Off” button for 2 seconds and then the up
arrow button simultaneously.
The last nine maintenance codes display and flash one after the
other.
To exit diagnostic codes and return the water heater to normal
operation, press and hold the “On/Off” button for 2 seconds and then
the up arrow button simultaneously.
Turn on the water heater by pressing the “On/Off” button.
Figure 80
Some of the checks below should be performed by a trained and qualified
professional. Consumers should never attempt any action that they are not
qualified to perform.
WARNING
1 2
No Flame
• Check that the gas is turned on at
the water heater, gas meter, or
cylinder.
• Ensure gas line, meter, and/or
regulator is sized properly.
• If the system is propane, make sure
that gas is in the tank.
• Ensure flame rod wire is connected.
• Ensure gas type and inlet gas
pressure is correct.
• Bleed all air from gas lines.
1 4
Heat Exchanger Overheat
• Measure resistance or voltage of
Overheat Switch.*
• Ensure it is not in forced Hi setting.
• Check heat exchanger surface for
hot spots which may be caused by
scale build-up. Refer to instructions
in manual for flushing heat
exchanger. Hard water must be
treated to prevent scale build up or
damage to the heat exchanger.