Noritz Water Heater Error Codes: NR and NRCP Series

Quick Answer

Noritz tankless water heaters display numeric codes like 11, 12, or 90 to indicate ignition or combustion faults. The most common fix is checking the gas supply and cleaning the flame sensor or air intake filters to restore proper operation.

If you're staring at a number on your Noritz remote right now, don't panic. These units throw codes because they're doing their job, protecting themselves before something breaks for real. Ignore it long enough and you're looking at a cracked heat exchanger or a seized fan motor, which turns a $40 fix into a $600 one. Most codes clear in under an hour.

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About These Noritz Waterheater Error Codes

Noritz tankless units are incredibly sensitive to gas pressure and venting fluctuations. I've found that nine times out of ten, a code pops up because a sensor caught something slightly out of spec. Could be a windy day messing with your exhaust. Could be a dirty flame rod. This guide breaks down what each fault actually means so you can figure out if it's a DIY fix or time to call someone.

Most Common Error Codes

No ignition (Code 11)40%

Flame failure during operation (Code 12)24%

Thermal fuse blown from overheating (Code 14)14%

Fan motor failure (Code 20)12%

Gas pressure abnormality (Code 16)10%

Symptoms You May Notice

You turn on a hot tap and get nothing but cold water, with a two-digit number sitting on the remote display
The unit clicks and sparks like it's trying to light, you can actually hear it attempting 3 times, then it just goes quiet and shuts down
Hot water cuts out mid-shower and a fault code appears that wasn't there when you started
The fan spins up for a few seconds, then the whole unit shuts down before any flame ever establishes
Unit worked fine all morning, now it won't fire at all and the error light is blinking in a repeating pattern

Tools Required for Diagnosis

FlashlightPhillips #2 screwdriverFlat-head screwdriverMultimeterScotch-Brite pad (for flame rod cleaning)Small wire brushPhone or camera (for recording LED blink sequence)

How to Identify Your Error Code

Frequently Asked Questions

Where do Noritz error codes display?

Most Noritz units show the code on the RC-7651M or RC-9018M wired remote. If you don't have one of those mounted on your wall, you'll need to pull the front cover off the heater. Look for a small LED on the green circuit board inside. It blinks in a sequence, pauses, then repeats. Count the blinks between pauses to get the code number. Pro tip: video it with your phone so you can count it accurately instead of guessing.

How do I view stored error history on a Noritz?

Hold the Temperature Up and Temperature Down buttons at the same time for about 3 seconds. The display shows 'H0' followed by the most recent code. Use the arrows to scroll through H1 to H9 for older faults. This is honestly one of the most useful features on these units. I've used it to catch intermittent issues that would've been invisible otherwise, like a Code 12 that only fired when the furnace and the water heater were both running at the same time.

Will a Noritz error code clear itself?

Sometimes. Minor nuisance trips from a brief gas pressure drop might clear when you cycle the hot water tap or just wait a few minutes. But safety-critical faults like Code 14 or Code 16 are hard locks. They need you to cycle the main power and, in a lot of cases, actually replace a component like the thermal fuse. The unit won't fire again until that part's physically fixed. Don't waste time resetting over and over if it keeps coming back immediately.

What is the most common Noritz error code?

Code 11. See it constantly. It just means the unit tried to light and couldn't confirm a flame. Usually it's a dirty flame rod coated with carbon residue. Clean it with a Scotch-Brite pad, takes about 10 minutes, and you're done. It can also show up if there's air in the gas line after recent work on your meter or other appliances. Open a gas burner on your stove for 30 seconds to purge any trapped air, then try the water heater again.

Is Noritz the same as Rinnai for error codes?

Similar code numbers, different machines. Both use '11' for ignition failure and '12' for flame failure, but the internal components and voltage specs are different. A Noritz fan motor isn't interchangeable with a Rinnai fan, and the troubleshooting sequence for the same code number can vary between the two brands. Always pull up the manual for your specific Noritz model. Don't cross-reference with a Rinnai guide or you'll end up chasing the wrong part.

How much does it cost to fix a Noritz error code?

Depends entirely on the code. A Code 11 from a dirty flame rod costs you nothing but 20 minutes of your time. A Code 14 thermal fuse runs about $15-30 for the part but you'll probably pay a tech $150-250 to diagnose and replace it since the unit won't reset until it's physically done. Code 29 from scale buildup usually means a descaling flush, which is $100-200 if a pro does it or about $30 in descaling solution if you're comfortable doing it yourself.

Related Noritz Waterheater Error Codes

Code: TROUBLESHOOTINGNoritz Tankless Water Heater Troubleshooting: 8 Common Problems and Fixes Code: CONDENSATE-DRAINNoritz Tankless Water Heater Condensate Drain: Blockage Codes and Fixes Code: 11Noritz Code 11: No Ignition Fix for NR and NRCP Series Code: 90Noritz Code 90: Combustion Abnormality or Exhaust Recirculation Code: 14Noritz Code 14: Thermal Fuse Blown - Overheating Fault Code: 29Noritz Code 29: Heat Exchanger High Limit Exceeded Code: 12Noritz Code 12: Flame Failure During Operation Code: 16Noritz Code 16: Abnormal Gas Combustion or Pressure Fault Code: 20Noritz Code 20: Combustion Fan Motor Failure Code: RESETHow to Reset a Noritz Tankless Water Heater and Clear Error Codes Code: NO-HOT-WATERNoritz Tankless Water Heater No Hot Water: 7 Causes and How to Fix Them Code: PRIORITY-LIGHTNoritz Water Heater Priority Light Flashing: What It Means and How to Fix It Code: IGN-FAILURENoritz Water Heater Ignition Failure: Causes When No Error Code is Shown

Same Fix on Other Brands

Rinnai waterheaterRinnai Tankless Water Heater Error Codes Navien waterheaterNavien Tankless Water Heater Error Codes

Models Known to Experience HUB Errors

This repair applies to most Noritz waterheaters with this error code. Common model numbers include:

NRCP199-DV, NRCP111-DV, NRCP842-DV, NR98-DV, NR83-DV, NR66-DV, NR711, NRC1111-DV

Written by

Raj Patel

HVAC & Water Systems Specialist · 15 years experience

Last verified for technical accuracy on March 14, 2026