Rinnai tankless water heater error codes

All Rinnai codes

Meanings are quoted from Rinnai's manuals. The "Who" column is our reading of the manual's remedy: whether an owner can do the first checks, or the fix belongs to a licensed technician.

How to read a Rinnai code

The code appears on the temperature controller. Most Rinnai codes are two digits, such as 11 or 79. Three of the codes listed here are letters: LC (shown as LC0 to LC9) means scale build-up, SS is a time-based service reminder, and FF marks maintenance done by a service provider Value manual, p. 35; RU manual, p. 75.

To see the last nine codes, turn the heater off with On/Off, hold On/Off for 2 seconds, then press Up while still holding it. Do the same to exit, then turn the heater back on RU manual, p. 73. In the history, “00” stands for LC RE manual, p. 52.

Code tables by manual: RU, pp. 73–75; RUR and RSC, pp. 72–74; RE, pp. 49–52; REP, pp. 48–51; Value (V65, V75, V94), pp. 34–35; V53De, pp. 28–29; VC (RL75, RL94, RLX94), pp. 37–38. The RX manual has no table and points to the tech data sheet inside the front cover SENSEI RX Installation and Operation Manual, p. 58, quoted here from the SENSEI RX/CX Tech Sheet.

Clearing a code

Rinnai has no single reset. What the manuals say, code by code:

• 03: turn off all hot water taps, then press On/Off twice RU manual, p. 73.
• 15 and 54: the RU table lists resetting the main power supply to the heater RU manual, p. 74. For 15, the other remedies in that row, the venturi motor and the gas valve assembly, are technician work.
• 25: the table row has no reset step. The RU manual’s installation test clears the code by turning the heater off with On/Off, waiting five seconds and turning the power back on RU manual, p. 55.
• SS: press On/Off five times within 5 seconds RU manual, p. 75. On RX models the reset is holding the A button until SS disappears SENSEI RX Installation and Operation Manual, p. 50. That button is on the PC board behind the front panel p. 67, the panel comes off only for service or maintenance p. 6, and the RX manual tells owners who see SS to contact their local service provider p. 50.
• LC: five presses of On/Off keep the heater running until a flush Value manual, p. 35. Clearing it after the flush differs by model; see the LC page.

If the heater will not operate, turn off the gas to the appliance and call a service technician or the gas supplier RU manual, p. 68.

When to stop and call a professional

If you smell gas, do not light any appliance, touch an electrical switch or use a phone in the building. Call the gas supplier from a neighbor’s phone, or the fire department if you cannot reach the supplier RU manual, p. 6. The Value and V53De manuals add “Leave the premises” Value manual, p. 28; V53De manual, p. 22.

If the heater overheats or the gas does not shut off, turn off the manual gas control valve by hand, never with tools. Do not use the heater if any part has been under water RU manual, p. 8.

Installation, service, the annual inspection and parameter changes belong to a trained and qualified professional RU manual, pp. 6, 8, 76. The Value, V53De and VC tables mark many remedies “licensed professional only” Value manual, p. 34. The troubleshooting guide behind the technician checks on these pages is for trained and qualified professionals only Troubleshooting Tankless Water Heater Diagnostic Codes, p. 3.

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