Rinnai Tankless Water Heater: Lock or unlock the KCM controller (LOC)
Lock or unlock the KCM controller (LOC) on a Rinnai tankless water heater: Locking one controller locks every controller in the system.
Applies to: Rinnai KCM tankless with MC-601-US controller
How to fix lock or unlock the kcm controller (loc): step by step
- To lock: press Priority and Up together for 5 seconds; a beep confirms it.
- To unlock: press Priority and Up together for 5 seconds again.
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 Tankless Water Heater codes
Source: Rinnai KCM Series Manual (U328-0700X04), p.55. 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.