Rinnai Rinnai RL94iN RL Series Tankless Water Heater 11 Error Fix: No Ignition

Error code 11 on the Rinnai Rinnai RL94iN RL Series Tankless Water Heater means: No Ignition. The unit attempted ignition but no flame was detected by the flame sensing rod. This is the most common Rinnai error code. The ignition sequence ran (fan spun up, gas valve opened, igniter activated) but the flame rod did not detect a flame. Causes include: (1) No gas supply — verify the gas meter is active, the manual shutoff valve at the unit is open, and for propane systems, the tank has fuel. (2) Dirty flame rod — the flame sensing rod is a small metal probe positioned in the burner flame path. It detects flame by sensing ionization current. Carbon buildup, corrosion, or a cracked porcelain insulator prevents flame detection even when flame is present. Remove and clean the rod with fine emery cloth or steel wool. (3) Faulty igniter — if no spark or glow is produced, replace the igniter. (4) Gas valve malfunction — the gas solenoid valve may not be opening. (5) Insufficient gas pressure — pressure must be at least 5 inches WC for natural gas. Have a technician check manifold gas pressure with a manometer. After correcting the cause, the unit must be power-cycled (unplug for 30 seconds or press the ON/OFF button twice) to clear the error and re-attempt ignition.

The most successful fix is "Test and Replace Igniter or Gas Valve" (hard difficulty, ~90 minutes). Estimated DIY cost: $15-$20. HomeMD has 2 community-ranked fixes for this error.

This error is rated critical severity. It is generally not urgent and can often be resolved with a simple DIY fix.

Yes — the top-ranked community fix ("Test and Replace Igniter or Gas Valve") is rated hard difficulty and takes about 90 minutes. Tools needed: T20 Torx screwdriver, Multimeter, Needle-nose pliers.

DIY cost: $15-$20. Professional repair typically costs $150-$250. Many homeowners save money by trying the top-ranked community fix first.

The Rinnai Rinnai RL94iN RL Series Tankless Water Heater has 8 other known error codes, including: 02 (Ignition Failure), 03 (Bath Fill Function Abnormality), 05 (Blocked Exhaust / Air Supply), 10 (Blocked Exhaust — Air Pressure Switch), 12 (Flame Failure), and 3 more.

Error code 11 also appears on 8 other Rinnai models: Rinnai RE180iN RE Series Non-Condensing Tankless Water Heater, Rinnai RL75iN RL Series Tankless Water Heater, Rinnai RSC160iN Condensing Combi Boiler, Rinnai RU130iN Sensei Super High Efficiency Plus Tankless Water Heater, Rinnai RU199iN Sensei Super High Efficiency Plus Tankless Water Heater, Rinnai RUR199iN Sensei Recirculating Tankless Water Heater, and 2 more. The fix may vary by model, so check each model's specific page for tailored repair steps.