Rinnai Error Codes: Full List for Tankless Water Heaters

How to read a Rinnai error code

The code flashes on the temperature controller. Rinnai's FAQ says error codes vary by product, so the same number can carry a slightly different name on different series. Find your model number on the rating plate before you look anything up. Rinnai's diagnostic guide puts that plate on the side of the water heater.

You can also pull up the last nine codes. On the RU and RUR models, the manual says to turn the water heater off with the On/Off button, then press and hold On/Off for 2 seconds and the Up button together. The codes flash one after the other. Repeat the same press to exit, then turn the heater back on.

On the RL and V models with the MC-91-2 controller, hold On/Off for 2 seconds and, while holding it, press the Up button. Press the same pair again to leave the code history.

If you smell gas, stop. Every Rinnai manual we opened says the same thing: do not try to light any appliance, do not touch electrical switches or use a phone in the building, and call your gas supplier from a neighbor's phone. If you cannot reach the gas supplier, call the fire department. We would add one thing: leave the house first and make the call from outside.

Rinnai error code list

This table covers every code in the owner's diagnostic tables of four Rinnai residential manuals: the RU and RUR condensing models (the SENSEI N series) and the RL and V non-condensing models. Where the series name a code differently, the meaning column says which series uses which wording. The "what you can check" column holds only the steps the manuals give owners.

Codes and owner steps from Rinnai's RU series installation and operation manual (100000467, section 5.6), its RUR series manual (100000508, section 5.6), the VC series manual for the RL models (100000244) and the Value Series manual for the V models (100000258), all opened October 2026. Each manual warns that some checks should be done only by a trained or licensed professional, and that consumers should never attempt anything they are not qualified to do.

Rinnai codes 10, 11, 12 and 14

People search for these four more than any other Rinnai code. Each has a short summary here, and three have a full guide of their own.

Code 10: air supply or exhaust blockage

The water heater cannot move enough air in or exhaust out. On the RU and RUR condensing models, a full condensate trap sets the same code. Start outside at the vent terminal, then check the condensate line and, on indoor RU and RUR units, the internal air filter. Our Rinnai code 10 guide walks through each check.

Code 11: no ignition

The heater tried to light and could not. Rinnai's first checks are that the gas is on at the water heater, the meter or the cylinder, and that a propane tank has gas in it. Everything past that involves gas pressure or ignition parts. See our Rinnai code 11 guide for the owner checks and what a technician does next.

Code 12: no flame

Rinnai calls code 12 "No Flame" in its owner tables and "Flame Failure" in its diagnostic guide. The owner checks match code 11: gas on, propane in the tank, and on RL and V models, nothing blocking the flue outlet. Our existing guide covers resolving Rinnai error code 12.

Code 14: overheat or thermal fuse

Rinnai's diagnostic code guide says code 14 is a sign of overheating and should be taken seriously. The overheat switch resets itself once the heat exchanger cools, but it keeps tripping until the cause is fixed. The manuals' checks for it include scale in the heat exchanger, the wrong gas type and airflow restrictions. Clear anything stacked around the unit or vent, then call a technician.

Other Rinnai codes with owner steps

The manuals give owners a step for a handful of other codes. Here they are in the manuals' own order.

Code 03: power cut during bath fill

This one appears if the power went off while the heater was filling a bath, and the manuals say water will not flow when the power returns. Turn off all hot water taps and press On/Off twice.

Code 25: condensate pump

RU and RUR models can drive an accessory condensate pump. Rinnai's diagnostic guide says code 25 appears when condensate backs up and trips the float switch, or when the pump stops working. Check that the pump is plugged in and running, and that its reservoir is empty. In the RU manual's test of this switch, you plug the pump back in, confirm condensate is flowing, then turn the heater off with On/Off, wait five seconds and turn it back on. That clears the code.

Code 65: water flow control

The water flow control valve failed to close during the bath fill function. All four manuals say to turn off the water immediately, stop the bath fill and have a qualified professional service the unit.

Code 79: water leak detected

On RL and V models, code 79 means water has been detected at the bottom of the unit. Turn off the water supply. The manuals then say to check all the plumbing inside the unit for leaks. That means taking the front panel off, so we suggest leaving it to a technician.

LC and SS: time to flush

An LC code (LC0 to LC9, logged as 00) on RL and V models means scale is building up in the heat exchanger. Rinnai says to flush it to prevent damage and to treat hard water. Pressing On/Off 5 times lets the heater run for now, but repeated LC codes eventually lock it out. Rinnai's diagnostic guide says the heater then runs for 70 hours before it locks out with another LC code.

RU and RUR models use SS instead, a service reminder set at installation. Push On/Off 5 times in 5 seconds to reset it, then book the flush. Rinnai's FAQ says to flush mineral deposits at least once a year. Our guide to water heater maintenance covers why.

No code, no hot water

If nothing happens when you open a hot tap, the manuals say to clean the inlet water filter and make sure the flow is above the model's minimum. Their filter steps: close the cold and hot isolation valves, put a bucket under the filter at the bottom of the unit, unscrew it, rinse it, refit it and open the valves. Our page on common water heater problems covers other causes.

When to stop and call a technician

Stop at any step that involves gas, electricity or taking the unit apart. Rinnai's V53De manual puts it plainly: call a licensed professional for any remedy that involves gas or electricity, or if you have any doubt about doing it yourself. Rinnai's diagnostic guide, which holds the full repair steps, says only trained and qualified professionals may follow it.

Have the code, the model number from the rating plate and the code history ready. Rinnai Customer Care is at 1-800-621-9419, as listed in its FAQ as of October 2026.

Which Rinnai models this list covers

• RU (SENSEI N series): RU199i, RU180i, RU160i, RU130i and the outdoor "e" versions. Manual 100000467, revision dated January 2021.
• RUR (SENSEI with pump): RUR199i, RUR160i and the "e" versions. Manual 100000508, January 2021.
• RL (VC series): RL75i, RL94i, RLX94i, RL75e, RL94e. Manual 100000244, August 2019.
• V (Value series): V65i, V75i, V94i, V94Xi and the "e" versions. Manual 100000258, April 2021.

Rinnai makes other tankless lines with codes of their own, including the SENSEI RX, the RE series, the V53De, the older KB and VB models and its commercial units. Rinnai's diagnostic guide covers those lines too, and it lists codes such as 02, 13, 18, 30 and 57 that appear in none of the four owner tables above. If your code is not in our table, check your own manual or call Rinnai. If you are choosing a replacement, our tankless water heater guide compares current models. If you own a Navien instead, our Navien error codes page covers that brand.