Richmond Tankless Water Heater Code 11 [Why+ How To Fix]

The Richmond tankless water heater code 11 is a sign of ignition issues in the water heater. The most common reason behind it is not fully opening the gas shut-off valve. Apart from that, the other potential reasons that cause this issue are:

  • Restricted Gas Flow
  • Bad Igniter
  • Faulty Gas Solenoid Valve
  • Venting Issues
  • Worn Out Igniter Warning Harness
  • Condensation
richmond tankless water heater code 11

Keep on reading to find out all about each of these issues in detail and learn how you can fix them. Without any more ado, let’s dive in!

Richmond Tankless Water Heater Code 11 [Why+ How To Fix]

We’ll discuss all the common reasons behind the error code 11 on your Richmond water heater in this section.

richmond tankless water heater

1. Not Fully Opening Gas Shut-Off Valve

The gas shut-off valve in your Richmond water heater needs to be fully opened so that the heater gets sufficient gas supply and operates properly. If you have recently drained your water heater or had some service done to it, you must have turned off the gas shut-off valve to do it.

not fully opening gas shut-off valve

You must turn it on all the way. Otherwise, there will be ignition issues with your heater and the error code 11 will pop up.


Thankfully, this problem is an incredibly easy one to fix. Just locate the gas shut-off valve and turn it all the way. The gas shut-off valve must be completely parallel to the gas pipe when it is fully turned on.

The gas shut-off valve being perpendicular to the gas lines indicates that it’s closed. If it’s already fully open, that means another issue is causing the error code. You need to keep on diagnosing the issue in that case.

2. Restricted Gas Flow

While not opening the gas shut-off valve is by far the most common way of blocking out the gas supply, it is not the only one. There are many other issues that can lead to restricted gas flow. Check whether gas is flowing to the main burner. If not, this is the issue that’s causing the trouble.

 gas lines leak

The first thing you need to keep in mind is that dirt and debris can get in the gas lines. They can obstruct the gas supply as it won’t be passing freely due to these things. Dents or kinks in the gas lines can also get in the way of them flowing freely. 

Air getting into the gas lines due to any leak can also block the proper flow of gas. If you’re using liquid propane as the fuel for your heater, your tank may be empty and that can cause this issue. Finally, the gas shut-off valve itself can be defective and that can also lead to restricted gas flow.


If you suspect that gas blockage could be the main culprit behind this issue, you need to contact your local gas supplier. It’s important that everything is checked out as issues with gas are always a serious matter.

Start by inspecting the gas lines and if there are any blockages, they need to clean out. If there’s air leaking into the gas lines, they need to be bled and replaced to solve this issue.

If you’re using LP and you’re running low on it, the solution is simple – fill up the tank and your heater should work fine again. For a bad gas shut-off valve, you simply have to replace it.

3. Bad Igniter

One of the most common reasons behind the Richmond tankless error code 11 is a bad igniter. The job of the igniter is to create a spark so that the burner lights up. A defective igniter will not generate this spark properly and that’s what leads to the error code.

richmond tankless water heater bad igniter

There are many ways in which you can diagnose whether you have a bad igniter. The first and easiest method is to remove the front panel of your tankless water heater and inspect it for damage.

Sometimes, a visual inspection will reveal that the igniter is cracked. If you’re not sure whether you have a bad igniter, you can test it by cycling your heater to start the ignition.

The voltage across the wires of the connector should be in the range of 108 and VAC. If the multimeter reading is in a normal range, that means your igniter is working properly. However, if the reading is out of that range, you can be sure that the igniter isn’t working properly.

When you have confirmed that there are issues with the igniter, it usually means one of two things – either the igniter is dirty or it’s completely damaged.


It’s possible that the igniter is just dirty and not yet damaged. In that case, you can get it to work again after cleaning it. Turn off the hot water to make sure that no accidents occur when you attempt to clean the igniter.

Remove the front cover and locate the electrode of the igniter. It’s always the electrode that will get dirty due to the build-up of carbon deposits and dirt. Rub it with 100-grit sandpaper to get rid of the carbon deposits from it.

Once you’re done, put your heater back together. Give it a power supply and gas supply, and check if the error code goes away. If the heater works properly now, your problem is solved. You may still have to replace the igniter soon as it can go bad with time.

However, if cleaning the igniter doesn’t do the trick, it means you’re dealing with a defective igniter. There is only one solution for it – you have to replace it. Follow these steps to do it:

Step 01 – Turn The Power Off

  • Make sure you turn the heater off by flipping the circuit breaker and also unplug the power outlet from the heater after removing the front panel.
  • Shut off both the cold water inlet and the hot water outlet lines.
  • Drain the water remaining in the heater using the relief valve.

Step 02 – Remove The Igniter

  • Locate the igniter coil in the heater.
  • Pull out one end of the igniter coil by pulling the plastic insert
  • Remove the igniter coil from the heater by removing the screw on the other end that’s holding it in place.

Step 03 – Replace The Igniter

  • Place the new igniter in place of the old one and tighten it by securing the screw in place.
  • Put the plastic insert back in and give power to the heater.
  • Turn on the cold water line, hot water line, and gas supply.

That’s how you can easily replace the igniter on your own. When you turn on the heater and let it run for a while, the error code should go away if the igniter was causing the issue. If the issue still persists, there’s most likely another reason behind it.

4. Faulty Gas Solenoid Valve

If you see the error code 11 on your Richmond tankless water heater where the igniter and the fan seem to be working properly but the main burner doesn’t ignite, the issue most probably lies with one of the gas solenoid valves.

Get a multimeter and start checking the resistance of the solenoid valves. Start by inspecting the gas inlet solenoid valve and see if the resistance value is between 0.8 to 2.4 ohms as that’s the normal range.

If there is no resistance, it means that the gas inlet solenoid valve is defective. But if the resistance of the gas inlet solenoid valve is within the acceptable range, check the other solenoid valves.

If any of them are out of range, that also means that there’s an issue with the gas control assembly. However, if they are in the normal range, that means there’s nothing wrong with them and there’s most likely another issue causing the error code.


If your diagnosis reveals that you have faulty gas solenoid valves, you have to replace the gas control assembly. It can be a tough job. So, we recommend taking the help of a qualified technician to do it.

5. Venting Issues

Another common reason behind your Richmond on-demand water heater showing the error code 11 is venting system issues. There are many regulations that you must adhere to so that your heater functions properly and you can be safe while using it.

richmond tankless water heater venting issues

You can find all of these regulations in the owner’s manual of your water heater. For example, you are supposed to use pipes of a specific diameter and it should be the same for both intake and exhaust pipes.

Even if you have set up everything correctly, plenty of things can still go wrong with the venting system. If there are leaks anywhere, it can lead to all sorts of trouble. Exhaust gases can get mixed with the intake port and get sent back to the combustion chamber.

There will be less oxygen in the combustion chamber and that can lead to the error code 11. Using the venting adapter of the wrong size can also cause several issues. Cobwebs or insects getting into the venting can also be the reason behind getting the error code.


There’s such a wide range of things that can go wrong with the water heater that it’s impossible to give a standardized solution. It requires a thorough inspection of the venting system.

If there are cobwebs and other dirt blocking the smooth flow within the vents, they need to be cleared. The pipes should be of the same diameter and made of the right material.

If the exhaust gases are getting mixed in the intake port, they need to be adjusted to fix this issue. Once you check all the boxes as per your owner’s manual, the error code 11 in your on-demand Richmond tankless water heater should go away.

6. Worn Out Igniter Wiring Harness

The wiring harness of the igniter supports it. The wiring harness is subject to wear and tear if it’s used for a long period. When the wiring harness wears out, it can trigger error code 11.

worn out igniter wiring harness

You can easily inspect the wiring harness by removing the burner cover. If there are visible signs of damage to it, you have found the culprit. Otherwise, you need to keep it moving with the diagnosis.


Whether the wiring can be repaired or needs to be replaced depends on the severity of the issue. We recommend hiring an expert to do this job if you don’t have a deep knowledge of working with electronics.

7. Condensation

When there’s condensation inside your water heater, it can lead to a serious issue and cause error code 11. Even if there’s a little bit of it inside your heater, it can go into ignition failure mode.

richmond tankless water heater condensation

You have to inspect the inside of your water heater to know if you’re facing this issue. Flip the circuit breakers, turn off the gas supply, and remove the front cover of your heater. If there are traces of water inside the heater, you have just found the culprit causing the error code.


You need to dry the condensation inside the error so that you can get rid of the error code and it starts working properly. Use a hair dryer to get all of the condensations out and put the heater back together.

Turn off the water heater and if the error code goes away, you’re good to go. It’s a good idea to inspect the condensate drain at regular intervals and make sure it’s working properly to avoid this issue in the future.


How long does an igniter last in Richmond tankless water heaters?

The igniters of the Richmond tankless heaters usually last for 10 years. But if you take good care and maintain your heater well, the igniter can last as long as the heater itself.

Is there a reset button in Richmond tankless water heaters?

There is no reset button in Richmond tankless water heaters. You have to turn the unit off, keep it turned off for a while, and turn it back on to reset it. Learn more from our ultimate guide on how to reset the Richmond water heater.

Can an ungrounded power supply lead to ignition failure in Richmond tankless water heaters?

When the power supply of your water heater isn’t properly grounded, there are two major risks. Firstly, you can get shocked and secondly, the heater can go into ignition failure. Get a professional to do the earthing to solve this issue.

What is the right gas pressure for Richmond tankless water heaters?

If you’re using natural gas, the acceptable range of gas pressure is 4″ w.c to 10.5″ w.c or 1.0kPa to 2.6kPa. For LP gas, it’s between 8″ w.c to 13″ w.c or 2.0kPa to 3.2kPa.


The Richmond tankless water heater code 11 represents ignition failure. If you face this issue, you need to deal with it quickly and get it fixed if you want to get hot water from your heater soon.

We’ve shared the most common reasons that can cause this error code and how you can fix it. Let us know what turned out to be the problem with your Richmond tankless water heater and how you fixed it by leaving a comment.

Note: Read our guide on why Richmond tankless water heater code 12 and how to fix it.

About David

David is a man who loves doing research and finding out the best solution to any type of heating appliance issues like heaters and fireplaces. Whenever he finds the perfect solutions to any issues of heating appliances after doing in-depth research, he loves to share them with his readers. In fact, his aim is to help his readers to fix the issues with their heating appliances easily.More about us .

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