Rinnai 11 Error: No Ignition / Burner Failed to Light
Diagnose Rinnai error code 11 (no ignition).
Ignition failure (Code 11). The water heater attempted to light the burner upon water flow demand, but flame was not detected at the ionization sensor.
Probable Causes
Yellow gas shutoff valve below unit partially or fully closed.
Air in new gas supply lines following installation or bottle change on propane systems.
Contaminated flame rod or cracked spark electrode ceramic insulator arcing to ground.
Diagnostic & Testing Steps
- •Code 11 flashes on digital temperature controller accompanied by audible beeper.
- •Water heater fan spins, but water flowing from faucets remains unheated.
- •Unit attempts ignition 3 times before locking out.
Tools & Equipment Required
- ✓Digital Multimeter (µA DC & Resistance)Measure flame rod microamp current (min 1.0 µA DC) and gas solenoid valve coil (30 - 50 Ω).
- ✓Digital Gas ManometerCheck dynamic operating gas supply pressure at inlet test point (5.0 - 10.5 in. W.C.).
- ✓Phillips #2 Screwdriver & 10mm SocketRemove outer casing screws to access combustion chamber and igniter assembly.
- ✓Non-Metallic Abrasive Pad (Fine Scotch-Brite)Polish flame sensing rod without scratching protective electrode alloy.
- ✓Gas Leak Detection Bubble SolutionVerify zero leakage around gas pressure test screws.
Fast Reset Sequence: Universal 5-Minute Power Isolation Reset
Before unmounting panels or beginning diagnostic procedures, attempt this manufacturer reset to clear transient microcomputer lockouts:
- 1.Press the Power or Cancel button to interrupt the active cycle.
- 2.Completely unplug the appliance or trip the dedicated wall circuit breaker.
- 3.Leave disconnected for 5 minutes to discharge internal power supply capacitors and reset microcontrollers.
- 4.Reconnect power and run a test cycle to confirm whether the error is transient or hardware-related.
- 1
Step 1: Verify Gas Valve Position and Tank Supply
[ ] DoneConfirm gas shutoff valve handle is parallel with piping and verify other gas appliances operate normally.
Verification:Gas is present at inlet test port; no upstream emergency regulators have tripped. - 2
Step 2: Inspect Spark Igniter and Flame Rod Probes
[ ] DoneUnbolt electrode mounting plate from combustion chamber. Polish flame rod with fine emery cloth.
Verification:Electrode ceramic body has zero cracks; spark gap is between 3.5 mm and 4.5 mm. - 3
Step 3: Test Gas Solenoid Valves and Clear Code
[ ] DoneMeasure resistance across gas valve solenoid coils (nominal 30–50 Ω per valve stage). Reconnect and press Power button.
Verification:Unit sparks, burner lights with crisp blue flame, and water heats to programmed setpoint.
Repair Solutions
Ensure manual gas valve handle is parallel with the copper/iron pipe.
Bleed air from gas line by performing 3 consecutive power resets.
Clean flame rod probe with steel wool to remove non-conductive oxidation.
Frequently Asked Questions
How do I clear Rinnai code 11 after turning on the gas valve?
Turn off the hot water tap, press the On/Off button on the controller twice to reset, and turn on the tap again.
Can improper venting cause Rinnai error 11?
Yes. If exhaust gases recirculate into the intake terminal, oxygen starvation prevents the burner from sustaining flame.