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Rinnai Boiler: Open the installer level (code C123)

Updated · by Aurora Star Tech Inc.

Open the installer level (code C123) on a Rinnai boiler: The Control Tower hides installer chapters behind an access code. Once entered, PARA, SERV and the rest become available; the control drops back to user level after 20 minutes without a key press.

Homeowner with a boiler problem? Call (647) 657-2977 or book a service call — licensed technicians across Vaughan and the GTA.

Applies to: E50CRN; E75CRN; E75CRP; E110CRN; E110CRP

How to fix open the installer level (code c123): step by step

  1. Hold MODE for 5 seconds until COdE shows
  2. Use + and - to dial C123
  3. Press STORE to confirm
Safety: Gas, electrical and refrigerant work must be done by a licensed technician. Turn off power and gas before servicing, never bypass a safety control, and always follow the manufacturer's manual for your exact model.

If the unit shows an error code, look it up: Rinnai Boiler codes

Source: Rinnai E-Combi Series Installation & Servicing Instructions (8U516009 V0116), p.56 (10.1). Written in our own words as a summary; always check the original manual.

General guidance for qualified technicians. The manufacturer's installation and service manual and local codes always take priority. Aurora Star Tech is not affiliated with, endorsed by or sponsored by any equipment manufacturer; brand and model names are used only to identify equipment and belong to their owners.

Emergency Boiler Repair

647-657-2977