Rinnai Error Code 79: Fan Current Detection

Severity
Warning
Type
digital display
Where to look
front panel
Estimated repair cost: $250 — $600 (parts + labor)
Warning: Your Rinnai water heater is experiencing a fan current issue. It's safe to troubleshoot, but call a professional if you're unsure.

How to Fix Rinnai Code 79

  1. Check for any visible damage or disconnection in the fan wiring
  2. Ensure the fan is not clogged with debris or lint
  3. If safe to do so, try resetting the unit by turning off the power at the breaker, waiting 30 seconds, then turning it back on

How to Reset Rinnai Code 79

  1. Turn off the unit using the power button on the front panel.
  2. Turn off the gas supply valve.
  3. Turn off the circuit breaker supplying power to the unit. Wait 30 seconds.
  4. Restore power at the breaker, then open the gas valve.
  5. Turn the unit back on. If the error returns, the underlying issue needs repair.

Resetting clears the code from the display but does not fix the underlying fault. If the code returns after reset, proceed to the diagnostic steps above.

What Does Rinnai Error Code 79 Mean?

Error code 79 on your Rinnai water heater indicates a problem with the fan current. The fan is crucial for venting combustion gases and maintaining proper operation. This error might be due to a faulty fan, fan motor, or wiring issue. The digital display will show '79' and the unit will lockout, preventing hot water production until the issue is resolved.

Common Causes

  • Faulty fan motor
  • Wiring issue between the fan and control board
  • Clogged fan or venting system
  • Control board malfunction

Diagnostic Steps

If... Check Expected
Fan is not spinning Fan motor resistance using a multimeter Less than 10 ohms
Wiring is intact and fan motor is good Control board for error codes or signs of damage No visible damage or error codes

Applicable Rinnai Models

Replacement Parts

Part OEM Number Est. Cost Where to Buy
Fan Motor RIN-100142800
Control Board RIN-100142700

Related Codes on Same Models

Other codes that affect the same Rinnai model families as 79.

Code Description Severity
02 Stagnant Water Detection Warning
10 Air Supply/Exhaust Blockage Warning
11 No Ignition Warning
12 Flame Failure Warning
14 Thermal Fuse Warning
16 Over-Temperature Warning
19 Electrical Grounding Warning
25 Condensate Overflow Warning
29 Condensate Neutralizer Warning
31 Inlet Thermistor Failure Warning