Rinnai Non-SENSEI error codes

"Non-SENSEI" is Rinnai's own name for everything it built before the SENSEI generation, and it is the largest installed base in American homes: the V, RL, RU, RUC, RUR, RUCS, RC, RE and C families, sold under REU-KA, KB, KBD, KBP, KCM, RE, VA, VB and VC part numbers. Rinnai documents them as one diagnostic table, so this page does too. Read the model number off the rating label rather than trusting the badge — RL75i and RL94i were sold in both the VB and the later VC ranges under the same name with different REU numbers. Six codes here exist nowhere else in the Rinnai range — 02, 31, 57, 58, 73 and 79 — and four more mean something different from the current units: code 34 is the combustion air thermistor rather than the lime detector, code 10 has no condensate trap in it, code 52 is the modulating solenoid (POV) rather than the gas valve as a whole, and code 71 names the individual SV0-SV3 solenoids. The RH180 hybrid tank-tankless is grouped under Non-SENSEI by Rinnai but carries five extra codes of its own (07, 13, 30, 35, FE) and is not covered here.

Models covered: C199i (REU-KBD3237FFUDC-US), C199e (REU-KB3237WDC-US), RC80i (REU-KA2530FFUD-US), RC80e (REU-KA2530WD-US), RC98i (REU-KA3237FFUD-US), RC98e (REU-KA3237WD-US), RU80i (REU-KB2530FFUD-US), RU80e (REU-KB2530WD-US), RU90e (REU-KBD2934WD-US), RU98i (REU-KB3237FFUD-US), RU98e (REU-KB3237WD-US), RUC80i (REU-KBD2530FFUD-US), RUC90i (REU-KBD2934FFUD-US), RUC98i (REU-KBD3237FFUD-US), RUR98i (REU-KBP3237FFUD-US), RUR98e (REU-KBP3237WD-US), RUCS65i (REU-KCM2025FFU-US), RUCS75i (REU-KCM2528FFU-US), RUS65e (REU-KCM2025W-US), RUS75e (REU-KCM2528W-US), RE140i (REU-VE1720FFD-US), RE140e (REU-VE1720WD-US), RE160i (REU-VE2125FFD-US), RE160e (REU-VE2125WD-US), RE180i (REU-VE2432FFD-US), RE180e (REU-VE2432WD-US), RE199i (REU-VE2737FFD-US), RE199e (REU-VE2737WD-US), REP160i (REU-VEP2125FFD-US), REP160e (REU-VEP2125WD-US), REP199i (REU-VEP2730FFD-US), REP199e (REU-VEP2730WD-US), R50LSi (REU-VA2019FFUD), R63LSe2 (REU-VA2024WD(A)-UC), R75LSi (REU-VA2528FFUD(A)), R75LSe (REU-VA2528WD(A)-UC), R94LSi (REU-VA2535FFUD), R94LSe (REU-VA2535WD-UC), R98LSi (REU-VA3237FFU), R98LSe (REU-VA3237W-US), R98LSi-ASME (REU-VA3237FFU-ASME), R98LSe-ASME (REU-VA3237W-ASME), RL75i (REU-VB2528FFUD-US), RL75e (REU-VB2528WD-US), RL94i (REU-VB2735FFUD-US), RL94e (REU-VB2735WD-US), V53e (REU-VAM1620W-US), V53De (REU-AM1620WD-US), V65i (REU-VC2025FFU-US), V65e (REU-VC2025W-US), V75i (REU-VC2528FFU-US), V75e (REU-VC2528W-US), V94i (REU-VC2837FFU-US), V94Xi (REU-VC2737FFU-US), V94e (REU-VC2837W-US), RL75i (REU-VC2528FFUD-US), RL75i(A) (REU-VC2528FFUD-US(A)), RL75e (REU-VC2528WD-US), RL75e(A) (REU-VC2528WD-US(A)), RL94i (REU-VC2837FFUD-US), RLX94i (REU-VC2737FFUD-US), RL94e (REU-VC2837WD-US)

Not your models? Check the model-number decoder before you read the table below — the code numbers repeat across series and the meanings do not.

Code	Error	Verdict
02	No burner operation during freeze protection	Call a pro
03	Power interruption during bath fill	DIY fix
05	Bypass flow control device fault	Part replacement
10	Air supply or exhaust blockage	Call a pro
11	No ignition	Call a pro
12	Flame failure	Call a pro
14	Overheat switch or thermal fuse tripped	Call a pro
16	Outlet water temperature too high	Call a pro
19	Electrical grounding fault	Call a pro
25	Condensate pump fault or blocked condensate drain	DIY fix
31	Burner thermocouple out of range	Call a pro
32	Outgoing water temperature thermistor fault	Part replacement
33	Heat exchanger thermistor fault	Part replacement
34	Combustion air temperature thermistor fault	Call a pro
38	Exhaust gas temperature sensor fault	Call a pro
41	Freeze protection sensor fault	Part replacement
51	Inlet water temperature thermistor fault	Part replacement
52	Modulating solenoid valve (POV) signal fault	Call a pro
54	Exhaust gas temperature too high	Call a pro
57	Burner overheat bi-metal switch tripped	Call a pro
58	Secondary heat exchanger switch tripped	Call a pro
61	Combustion fan motor fault	Call a pro
63	Recirculation low flow	DIY fix
65	Water flow control valve fault	Part replacement
70	PC board fault	Call a pro
71	SV0-SV3 solenoid valve fault	Call a pro
72	Flame rod fault	Call a pro
73	Burner thermocouple fault	Call a pro
79	Water leakage detected	Call a pro
FF	Maintenance performed marker	DIY fix
LC	Scale build-up in the heat exchanger	DIY fix

Every entry above is transcribed from the manufacturer's diagnostic documentation for this exact series, with the source cited on each code page.

Other Rinnai series

Different series, different code table — if your unit isn't a Non-SENSEI, check yours:

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