lc
Moderate
Rinnai · Tankless Water Heaters
Scale buildup warning in heat exchanger.
Quick Answer
Error code LC on your Rinnai Tankless Water Heaters means: Scale buildup warning in heat exchanger.. This is usually fixable — see the step-by-step guide below.
Affected Models
Likely Causes
How to Fix It
1
Flush/descale the heat exchanger per Rinnai service procedure.
2
Install or service water treatment/softening where needed.
3
Reset code after successful flush per model instructions.
4
Track recurrence interval to assess water quality severity.
5
Schedule preventive annual maintenance.
Pro Tip
This fix requires some technical knowledge. If you're unsure about any step, consider contacting support or a qualified technician.
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