Rinnai 11: No Ignition

The unit called for heat but failed to establish burner ignition. It's one of the most commonly reported Rinnai fault codes, and it's almost always a gas-supply or ignition-hardware problem.

Applies to: Rinnai tankless and condensing water heaters (RL, RU, RUC, RE, CU, CX series and similar residential models).

What it means

The unit called for heat but failed to establish burner ignition ("No Ignition"). This is one of the most commonly reported Rinnai fault codes.

Most common causes

Gas shut off at the water heater, meter, or propane tank
Empty propane tank or very low propane level
Incorrect gas type or inadequate gas pressure
Undersized gas line, meter, or regulator
Air trapped in gas lines after a new installation or tank swap
Incorrect DIP switch settings on the control board
Failed igniter, damaged igniter wiring harness, or a fouled burner

What you can safely check yourself

Confirm the gas valve at the water heater and at the meter/tank is fully open
If on propane, check the tank level and refill if empty or very low
Power-cycle the unit (turn off, wait, turn back on) and retry
On a newly installed unit, some air-in-the-line ignition failures clear after a few retries as air bleeds out

When to call a professional

Ignition still fails after confirming gas supply is on and adequate, you smell gas, or the unit is new and repeated retries don't clear it — this points to an igniter, wiring, or gas valve issue that needs a licensed technician.

Gas supply lines, gas control valves, and venting should only be worked on by a licensed plumber or HVAC technician.

What the fix costs

A diagnostic visit for a no-ignition fault typically runs $150–$600 depending on region and what's found (Angi, Fixr water heater repair cost guides). If it's a failed igniter or flame rod, expect a parts-and-labor repair in that range; a replacement gas control valve runs closer to $150–$450 installed. These are national ranges, not quotes — get a written estimate from a local licensed plumber.

Related codes

All Rinnai codes

Every Rinnai water heater fault code — the full list on one page.

Safety. If you smell gas at any point, stop, do not attempt to light the unit, ventilate the area, and call your gas utility or a licensed technician immediately. Do not keep power-cycling a unit that repeatedly fails to ignite.

Sources

Rinnai tankless water heater owner's manual and error code guide (manufacturer documentation)

This site is an independent reference, not a substitute for a licensed plumber or electrician. Gas water heaters can leak carbon monoxide, leak gas, or catch fire if serviced incorrectly. Anything involving the gas line, gas control valve, venting, or main electrical wiring should be handled by a licensed professional. Pages are written with AI assistance from the sources listed on each page and checked against them before publishing.