Rinnai Error Code 11: No Ignition, What to Check

What Rinnai error code 11 means

Every Rinnai residential manual we opened names code 11 the same way. The RU series manual and the RUR series manual call it "No Ignition (Heater Not Turning On)". The VC manual for the RL models and the Value Series manual for the V models use the same words.

In other words, the heater is not turning on, so a hot tap runs cold while 11 flashes on the controller. A close cousin is code 12, "No Flame", which shares most of the same owner checks. Our full Rinnai error code list shows how the two compare across all four series.

If you smell gas, do not try to relight anything. Rinnai's manuals say not to touch electrical switches or use a phone in the building, and to call your gas supplier from a neighbor's phone, or the fire department if you cannot reach the supplier. Leave the house first and make the call from outside.

Owner checks Rinnai allows for code 11

The manuals list the remedies for code 11 in order. On the RL and V models, the VC and Value manuals mark everything after the first few lines "licensed professional only". The gas checks below sit above that line, and they match the first steps in the RU and RUR manuals. A grounding check also sits above it in the VC table, but it means testing wiring, so leave that one to the technician.

1. Check the gas valve at the water heater

Rinnai's maintenance section says the manual gas control valve is usually located immediately below the water heater. Make sure it is open. A valve closed for earlier work is easy to miss.

2. Check the gas meter or the propane cylinder

The manuals say to check that the gas is turned on at the meter or the cylinder as well as at the heater. If your other gas appliances have stopped too, we would call the gas utility first and leave the meter to them.

3. Make sure a propane tank has gas in it

For propane homes, the manuals add one line: if the system is propane, make sure that gas is in the tank. If the gauge shows the tank empty, call your propane supplier.

4. Look at the condensate line on RU and RUR models

The RU and RUR manuals end their code 11 list with "ensure condensate line is not blocked". These condensing models have a condensate drain line, and the same manuals say to keep it free of snow and ice and make sure condensate is flowing freely. If you can see the line, check it is not blocked or frozen.

5. Try the hot water again

Once the gas is on, open a hot tap and watch the controller. The owner tables do not give a separate reset step for code 11. If the code comes straight back, stop there. Our general guide on resetting a tankless water heater covers power cycling, but cycling the power will not fix a gas or ignition fault.

If the heater lights but code 11 returns now and then, write down when it happens and tell the technician. Rinnai's diagnostic guide notes that condensate, debris or a faulty mechanical part inside the gas valve can stop it opening once in a while, which gives an on-and-off code 11. For hot water trouble with no code at all, see our list of common water heater problems.

When to stop

Stop once the gas is confirmed on and code 11 still shows. Everything else on Rinnai's list involves gas pressure, gas lines or electrical parts. The manuals' own warning is that some of the checks should be done only by a trained and qualified professional, and that consumers should never attempt anything they are not qualified to do.

Rinnai's V53De manual is the most direct: call a licensed professional for any remedy that involves gas or electricity, or if you have any doubt about doing it yourself. Do not open the front panel, bleed gas lines or test the igniter.

What a technician does for code 11

Rinnai's diagnostic code guide is written for professionals only, but it shows what a service visit should cover. In broad order, the technician:

• confirms every gas valve is open and a propane tank is sized for the heater
• checks that air was purged from the gas lines after installation
• measures inlet gas pressure against the rating plate, with every gas water heater at the location firing
• confirms the gas type matches the heater and its gas type setting
• tests the igniter for a spark and checks the electrode and flame rod are tight
• removes the igniter and flame rod to look for carbon or white build-up
• inspects the venting, its length and the high-altitude setting
• checks the wiring harnesses for moisture

If those pass, the guide's remaining suggestions include replacing the gas valve or the circuit board, and on non-condensing models, reseating burners that shifted. The guide also points to undersized gas piping or a faulty regulator. In that case it says to have the gas system checked by a gas technician who handles system sizing.

On a new installation, three items on that list trace back to the install itself: air left in the gas lines, the wrong gas type, and inlet gas pressure that falls below the rating plate minimum.

Code 11 vs code 12 vs code 10

These three codes often get mixed up. Here is how Rinnai's manuals separate them and where each owner check starts.

Codes from Rinnai's RU (100000467), RUR (100000508), VC (100000244) and Value Series (100000258) manuals, opened October 2026.

Calling Rinnai

Rinnai's FAQ says error codes vary by product and points owners to Rinnai or their local installer to find the root cause. Rinnai Customer Care is at 1-800-621-9419 as of October 2026.

Before you call, note the model number from the rating plate on the side of the heater and the code history. On RU and RUR models, turn the heater off with On/Off, then press and hold On/Off for 2 seconds and the Up button together. On RL and V models, hold On/Off for 2 seconds and press Up while holding it. The last nine codes flash in turn. If the same 11 keeps showing up, tell the technician how often.