- Boilers
- Tankless gas water heater
11
Rinnai 11 on a tankless water heater: no ignition
Risk level
High
Professional inspection is recommended.
Urgency
High
Quick answer
The heater tried to light the burner and did not ignite. Check that gas is turned on at the heater and the meter and that a propane tank has gas. If it still will not operate, turn off gas to the heater and call a licensed professional.
Safety first
Stop and check this first
- Do not try to light the burner by hand: Rinnai states the heater lights it automatically with an ignition device. Do not remove the front panel to look for a flame.
- If you smell gas: do not try to light any appliance, do not touch any electrical switch and do not use any phone in the building. Call your gas supplier from a neighbor's phone and follow its instructions; if you cannot reach it, call the fire department.
Safe checks you can perform
- Gas turned on at the heater and the meter
- Propane tank level, if you use propane
- Recent code history on the controller
- Turn off gas to the heater if it will not operate
Leave these tasks to a qualified professional
- Do not attempt this professional task: Test the igniter, electrode and flame rod
- Do not attempt this professional task: Check gas valve, venting and board ground
- Do not attempt this professional task: Measure inlet gas pressure and confirm gas type
What a technician must be able to justify
Technician visit
These are the steps they must carry out and show you. Tick them as they work: if steps are skipped, do not accept a part swap.
These are not instructions for opening or handling the equipment yourself. They are the checks that should support a technical conclusion.
Test the igniter, electrode and flame rod
What they doWith gas off, the professional checks for spark, tightness of the electrode and flame rod, wiring and carbon build-up, and the voltage to the ignition system during the ignition cycle against the Technical Data Sheet.
They must show youphotos of the electrode and flame rod and the measured voltage against the data sheet.
In writingpart replaced and why.
Check gas valve, venting and board ground
What they doIf supply and ignition parts are correct, the professional checks the gas solenoid valves, the vent system and the PC board ground wire.
They must show youseveral successful ignitions after the repair.
In writingwhich check failed.
Measure inlet gas pressure and confirm gas type
What they doWith a manometer at the heater's test port and all gas appliances at the site firing on high, the professional compares inlet pressure with the rating plate and checks that gas type matches the plate and the gas type setting.
They must show youthe measured inlet pressure against the rating plate.
In writinggas type confirmed, pressure measured and whether the line was purged.
Before accepting a part or repair
Nothing has been shown yet. Do not accept a part swap based on the code alone.
Follow these steps
Note: Follow the documented order. An error code identifies the affected system, but it does not prove by itself which part has failed.
Gas turned on at the heater and the meter
- Who:
- you.
- How:
- without removing any panel, look at the manual gas valve on the side of the heater and at the valve by the gas meter. Rinnai's owner remedy for 11 is to check that the gas is turned on at the water heater, gas meter or cylinder.
- Result that matters:
- whether a valve was closed.
- If a valve was closed:
- follow Rinnai's operating instructions: power off, valve to OFF, wait five minutes and smell for gas, including near the floor. If there is no smell, turn the valve fully ON, power on and open a hot tap.
- If both valves were already open:
- the gas supply branch is still not ruled out; continue with the next check.
- Evidence to keep:
- photo of each valve position.
Evidence: Rinnai Value Series tankless water heater installation and operation manual
Propane tank level, if you use propane
- Who:
- you.
- How:
- read the tank gauge or ask your propane supplier. Rinnai lists an empty propane tank among the first causes of 11.
- Result that matters:
- whether there is gas in the tank.
- If the tank is empty or very low:
- have it refilled. Rinnai lists bleeding air from gas lines as a licensed professional task, so tell the technician the tank ran out.
- If the tank has gas or you use natural gas:
- continue with the next check.
- Evidence to keep:
- gauge reading and refill date.
Evidence: Rinnai Value Series tankless water heater installation and operation manual
Recent code history on the controller
- Who:
- you.
- How:
- on the MC-91-2 controller of Value Series models, press and hold On/Off for 2 seconds and, while holding it, press the up button. The last 9 codes flash one after another. Repeat the same keys to exit.
- Result that matters:
- whether 11 repeats and which other codes appear.
- If only 11 repeats:
- the problem is consistent and the technician starts from this code.
- If 11 alternates with 10, 12 or 14:
- note every code, because they change the diagnosis.
- Evidence to keep:
- a photo or video of the code sequence with the date.
Evidence: Rinnai Value Series tankless water heater installation and operation manual
Turn off gas to the heater if it will not operate
- Who:
- you.
- How:
- follow Rinnai's "To turn off gas to appliance": turn off electric power with the On/Off button, set the thermostat to the lowest setting and turn the manual gas valve on the side of the heater clockwise to the full OFF position.
- Result that matters:
- the heater stays off and isolated until a licensed professional or the gas supplier checks it.
- If you smell gas at any point:
- stop and follow the gas warning on this page.
- If you do not smell gas:
- leave it off and call your licensed professional or gas supplier, as Rinnai's operating instructions say.
- Evidence to keep:
- time you turned it off and the last code shown.
Evidence: Rinnai Value Series tankless water heater installation and operation manual
Still not solved
If the error persists, stop here. See what the technician must do and show you.
Where this code applies
A code is meaningful only inside the right product and version context.
Primary scope
- System
- Boilers
- Brand
- Rinnai
- Product type
- Tankless gas water heater
Known code variants
- 11
- Ariston Velis 11
- calentador Rinnai 11
- código 11 Rinnai
- E11
- E:11
- Er 11
- error 11 Rinnai
- Fujitsu 11
- Fujitsu E11
- Rinnai 11
- Rinnai 11 no ignition
- Rinnai code 11
- Rinnai code 11 tankless
- Rinnai error 11
- Toshiba 11
- Toshiba error 11
- Velis error 11
What it means
Rinnai defines code 11 as no ignition: the burner did not light during the ignition sequence. Its owner remedies start with the gas supply at the heater, meter or propane tank. The professional list continues with grounding, gas type and inlet pressure, air in the gas line, gas line and regulator sizing, igniter and wiring, flame rod, gas valve, burner seating, venting and the PC board ground. The code does not say which one failed.
Warnings and stop conditions
- Higheditorial warning
Do not try to light the burner by hand: Rinnai states the heater lights it automatically with an ignition device. Do not remove the front panel to look for a flame.
Evidence: Rinnai Value Series tankless water heater installation and operation manual
- Criticalsource verified
If you smell gas: do not try to light any appliance, do not touch any electrical switch and do not use any phone in the building. Call your gas supplier from a neighbor's phone and follow its instructions; if you cannot reach it, call the fire department.
Evidence: Rinnai Value Series tankless water heater installation and operation manual
Symptoms and causes
Probable causes · in order
- Gas turned off or propane tank emptyPossible
Rinnai's first owner checks. Fits if gas was recently shut off, the meter was worked on or the tank ran low.
Evidence: Rinnai Value Series tankless water heater installation and operation manual
- Air in the gas line or insufficient inlet pressurePossible
Typical after a new installation or gas work, or with an undersized gas line or regulator. Only a professional with a manometer can confirm it.
Evidence: Rinnai USA troubleshooting tankless water heater diagnostic codes · Rinnai Value Series tankless water heater installation and operation manual
- Igniter, electrode or flame rod problemPossible
No spark, loose electrode or flame rod, damaged wiring or carbon on the flame rod. Rinnai notes that a loose flame rod or electrode can cause code 11 or 12.
Evidence: Rinnai USA troubleshooting tankless water heater diagnostic codes
- Gas valve, venting or boardPossible
Rinnai checks gas solenoid valves, venting and the PC board ground after the supply and ignition parts.
Evidence: Rinnai USA troubleshooting tankless water heater diagnostic codes · Rinnai Value Series tankless water heater installation and operation manual
Virtual technician
Does 11 still appear after these checks?
Answer a few questions to narrow down the likely cause and the safest next action. Guidance only - it never replaces a professional.
Sources and technical references
- 1
Rinnai USA troubleshooting tankless water heater diagnostic codes
Rinnai America · 2024 · manual
- 2
Rinnai Value Series tankless water heater installation and operation manual
Rinnai America · 2019 · manual
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