Rinnai Tankless Water Heater Error Code 82: How to Fix It

Easy 15-30 minutes Medium Severity Verified June 2026
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Error Code
82
Brand
Rinnai
Product Type
water_heater
Severity
Medium
DIY Difficulty
Easy
Estimated Fix Time
15-30 minutes
Rinnai error code 82 indicates that the internal humidity inside your tankless water heater is too high. This usually happens due to condensation buildup or blocked vents. Follow these steps to safely resolve the issue and restore hot water.
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Tools You'll Need

How to Fix Error Code 82

  1. Turn Off and Unplug the Heater

    Always turn off gas and power before servicing to prevent electric shock or gas leaks.

  2. Inspect the Intake and Exhaust Vents

  3. Check the Condensate Drain Line

    Condensate is acidic; avoid skin contact and wear gloves.

  4. Dry the Interior Components

    Do not use high heat or direct water; keep hairdryer moving to avoid heat damage.

  5. Reset the Heater

    If error persists after drying and clearing vents, there may be a faulty humidity sensor.

Parts You May Need

Humidity sensor
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Humidity sensor
Check Price on Amazon
Humidity sensor
Check Price on Amazon
Humidity sensor
Check Price on Amazon
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When to Call a Professional

If error code 82 returns after thorough cleaning and drying, or if you notice burnt smells or repeated error codes, call a Rinnai-certified technician to inspect the humidity sensor or control board.

Frequently Asked Questions

How do I reset a Rinnai tankless water heater after error 82?
Unplug the unit or turn off the dedicated circuit breaker for 30 seconds, then restore power. If error persists, check vents and drains.
What causes internal humidity in a Rinnai water heater?
Common causes include blocked vents, a kinked or clogged condensate drain line, or excessive condensation from cold water entering the heater.
Can I use my Rinnai water heater with error code 82?
No, error 82 will prevent the heater from operating to avoid component damage. Fix the issue before resuming use.
Why does error 82 keep coming back?
Recurring error indicates an underlying issue like a blocked vent system, a failed humidity sensor, or improper installation. Professional inspection is recommended.
Does error 82 mean I need a new water heater?
No, error 82 is typically resolved without replacing the unit. Only if internal components are severely damaged would replacement be needed.

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