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ErrBase

Noritz Code 11: No Ignition Fix for NR and NRCP Series

Quick Answer

Noritz Code 11 means the water heater tried to ignite three times and failed on all attempts. The most common cause is a dirty or corroded flame rod that cannot sense the flame even when gas is present. Other causes include gas supply that is off or at low pressure, a failed spark igniter, or a faulty gas valve.

Noritz Code 11 means the water heater tried to ignite three times and failed on all attempts. The most common cause is a dirty or corroded flame rod that cannot sense the flame even when gas is present. Other causes include gas supply that is off or at low pressure, a failed spark igniter, or a faulty gas valve. Clean the flame rod with fine steel wool as the first repair step. If the unit clicks during ignition attempts, the igniter is working and the problem is likely the flame rod or gas supply.

NoritzWaterheaterSeverity: highDifficulty: intermediate78% DIY Success
Time to Fix
30–90 min
Difficulty
intermediate
Parts Cost
$12 – $280
Tools Needed
Phillips screwdriver, Multimeter
Wrong code?

Not seeing 11 on your display?

Select what your appliance is actually doing and we'll take you to the right guide.

error code on display
HUB
flame lost during use
12
will not ignite
IGN-FAILURE
error code on display
RESET
no ignition
Rinnai11
no ignition
NavienE003

What Does the 11 Code Mean?

Three ignition attempts failed with no flame detected. Start with flame rod cleaning before replacing parts.

Most Likely Causes

Based on aggregated repair data, here is the probability breakdown for this error code:

Dirty or corroded flame rod preventing flame signal40%
Gas supply off, valve closed, or pressure too low24%
Gas valve solenoid coil failure22%
Failed spark igniter not generating spark14%

Symptoms You May Notice

  • No hot water with Code 11 on display
  • Audible clicking during startup with no flame
  • Unit cycles through ignition and shuts down
  • Cold water at all fixtures

Can you reset a Noritz waterheater to clear the 11 code?

Press the power button to turn the unit off, wait 30 seconds, then press it again to restart. If Code 11 returns immediately, the root cause has not been resolved. After cleaning the flame rod or replacing a part, always perform a reset before testing.

Tools Required for Diagnosis

Phillips screwdriverMultimeterFine steel wool (000-0000 grade)Combustible gas detector

Diagnostic Checklist

Follow these steps in order. We start with the easiest external fixes before opening up the machine.

1

Verify gas supply

Verify gas supply: confirm the manual gas shutoff valve at the unit is fully open (handle parallel to pipe). Turn on a gas stove or other gas appliance to confirm active gas service.

2

Remove the front access panel (2-4 screws)

3

Clean the flame rod tip with fine steel wool (000 or 0000 grade)

4

Listen during an ignition attempt

5

Test the gas valve solenoid coils with a multimeter set to resistance

Replacement Parts

If your diagnostic testing proves the component has failed, you will need a replacement. We recommend OEM parts over aftermarket for water-handling components.

Part Name
Flame Rod (Flame Sensor)100001706 · $12–$25
Spark Igniter Assembly100001714 · $20–$35
Gas Valve Assembly100161840 · $150–$280

Repair vs. Replace Calculator

Appliance Age (Years)7 Yrs
Labor Approach
Our Verdict
REPAIR
Estimated Cost: $146 (Parts) vs $1150 (New Machine)

Frequently Asked Questions

What does Noritz Code 11 mean?
Code 11 means the unit attempted to ignite three times and failed on every attempt. The flame rod never detected a flame signal. It is not a lockout that requires a service call by itself - cleaning the flame rod resolves the fault in about 45% of cases.
Can I clean the Noritz flame rod myself?
Yes. The flame rod is accessible after removing the front panel. Disconnect the single wire connector, unscrew the rod, and rub the tip with 000-grade steel wool until it is bright metal. Reconnect, reset, and test. The process takes about 15 minutes.
How do I know if the Noritz spark igniter is working?
During an ignition attempt, you should hear rapid clicking. If you hear clicking but the unit still gets Code 11 after flame rod cleaning, the igniter is likely working and the problem is gas supply or the gas valve. If there is no clicking at all, the igniter or igniter control circuit has failed.
Noritz Code 11 vs Code 12 - what is the difference?
Code 11 means the unit never ignited at all during startup. Code 12 means the unit successfully ignited but the flame went out during operation. They share some causes (dirty flame rod, gas pressure) but Code 12 also points to flow-related issues or pressure fluctuation mid-cycle.
How long does gas valve replacement take on a Noritz?
A licensed plumber typically spends 1 to 2 hours on a gas valve replacement, including pressure testing afterward. This repair should not be performed by untrained homeowners because it involves disconnecting and reconnecting live gas lines.

Related Noritz Waterheater Error Codes

Code: HUBNoritz Tankless Water Heater Error Codes: Complete NR and NRCP Series GuideCode: 12Noritz Code 12: Flame Failure During OperationCode: IGN-FAILURENoritz Water Heater Ignition Failure: Causes When No Error Code is ShownCode: RESETHow to Reset a Noritz Tankless Water Heater and Clear Error Codes

Same Fix on Other Brands

Rinnai waterheater11: Rinnai Code 11: No IgnitionNavien waterheaterE003: Navien E003 Error Code: Ignition Failure

Models Known to Experience 11 Errors

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

NRCP199-DV, NRCP111-DV, NR98-DV, NR66-DV, NR711

Last verified for technical accuracy on March 14, 2026