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Understanding Rinnai Error Codes: What They Mean & What to Do
Rinnai tankless water heaters are among the most reliable on the market, but like any appliance, they can occasionally run into issues. When that happens, your unit may display an error code. This guide will help you understand what those codes mean—and when it's time to call in the pros.
Error Code
Meaning
What You Can Do
When to Call a Pro
Error Code 10
Air Supply / Exhaust blockage
Check for blockages in venting system.
If issue persists after clearing vents.
Error Code 11
Ignition Failure
Ensure gas is on and reset unit.
If unit won't ignite or is still showing this code.
Error Code 12
Flame Failure
Check gas supply and flame rod.
If no flame visible or frequent error repeats.
Error Code 16
Over Temperature Warning
Flush unit and check for scale buildup.
If unit overheats or error reappears.
Error Code 25
Condensate Drain Blocked.
Inspect condensate line for clogs.
If line is blocked or water is pooling.
Error Code 70
PCB Fault
Reset the unit.
If code returns, circuit board may be faulty.
Error Code LC
Scale Buildup
Descale your unit with vinegar or a flush kit.
If you're unsure how or it reoccurs often.
What You Can Do
-
Power cycle the unit (turn off for 30 seconds, then back on)
-
Check your gas and water supply valves.
-
Ensure the air intake and venting are clear.
-
Reset the unit using the controller.
Avoid
-
Opening the units internal components
-
Trying to fix gas or electrical issues by yourself.
Still seeing an error?
Let us handle it.
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