Error Code 00; Warning Code 05 - Rheem RTG2-42 Troubleshooting Manual

Error Code 00

Explanation: One Hour continuous combustion timer is activated. Unit has a 60 minute time that
will shut off the main burner if used in excess of one hour. Cold water will continue to flow thru
the unit. (First generation products only – manufacture date thru Jul 06; models manufactured
after August 2006 do not have a 60 minute timer.)
Was the unit
used
continuously
for more than
one hour?
Yes
Unit will shut down automatically after
60 minutes of continuous use.
Turning off the hot water will reset the
timer.
Turn off or remove circulation pumps.
Unit is not designed for continuous
operation with circulation systems.

Warning Code 05

Explanation: Imperfect Combustion Alarm is flashing. This monitor code explains the unit is
having trouble maintaining a good combustion flame. The ODS sensor is activated and trying to
resolve the fuel-air mixture issue. At a minimum check the following in all cases:
1. Clean air inlet filter.
2. Check for adequate combustion air ventilation openings.
3. Check and clean combustion air fan.
Is the Error
Code "05"
flashing in the
remote control
display?
Yes
No
Unit appears to be OK. Try to restart.
No
Replace Circuit Board.
No
Unit appears to be OK. Try to restart.
Unit is trying to resolve imperfect combustion. Increase fresh air to
the unit. If the Rheem tankless cannot resolve the problem on its own,
it will shut down with an error code of "13".
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SVC 810 Tankless Troubleshooting Manual
Is Error Code
"00" displayed?
Yes