Richmond Water Heater Pilot Light Won’t Stay lit

Richmond Water heater pilot light won’t stay lit! Then, the thermocouple is at fault. Yes, in most cases, thermocouple is the mail culprit. But it doesn’t mean this part will be the culprit every time. 

There are other reasons too that can cause the pilot light to not stay lit. For example, a failed limit switch, plugged flammable vapor screen, or a faulty gas valve can also prevent the pilot light from staying lit. 

And this guide will introduce you with all the possible reasons that can cause the pilot light to go out. The best part is- I will als0 walk through the troubleshooting steps to solve them. So, let’s dive in. 

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Richmond Water Heater Pilot Light Won’t Stay Lit [7 Easy Solutions]

Your Richmond Water Heater pilot light won’t stay lit due to several reasons. These include a bad thermocouple, a tripped limit switch, plugged flammable vapor sensor, and a faulty gas valve. 

Besides, bad thermistor, tripped thermal release device, and blocked air intake are other caveats that prevent the pilot light from coming on. 

Below, I will break down how you can troubleshoot each of them. So, keep scrolling. 

01. Thermocouple Goes Bad

A bad thermocouple is one of the main culprits that prevent the pilot light from staying lit. Besides, you can’t light the pilot if the thermocouple gets dirty or bent. 

Testing the thermocouple electrically, you can easily determine whether the thermocouple gets bad or not. 

Testing the thermocouple
*Testing the thermocouple*

First off, use an adjustable wrench to remove the thermocouple from the gas control valve. 

Secondly, grab a multimeter and set it to the Volt DC option. Now, attach the red wire to the copper and the black one to the end of the thermocouple. Set the gas valve to pilot and hold down the pilot button. 

You can find the voltage starts rising as the thermocouple heats up. A healthy thermocouple should read 20 millivolts. If you don’t get this reading, you must replace the thermocouple. 

How To Fix: 

To replace the thermocouple, you should remove the burner assembly out of the unit. So, make sure you turn the gas supply off to your water heater. 

Then, remove other connections like the pilot line and the gas line from the gas valve. Finally, pull out the burner assembly from the unit. Locate the thermocouple and ensure it’s free from dirt & debris. 

If it’s at fault, remove the thermocouple from the burner assembly. Then, get a new thermocouple and install it. Now, assemble the burner again. Before replacing the gas burner into its place, ensure the thermal release device is intact. If it gets broken, you can’t light the pilot. 

Also, clean the combustion chamber area. Otherwise, it will cause the pilot light to not come on. Finally, put the burner assembly back into the unit and connect all the lines to the gas control valve you unhooked. 

02. A Failed Limit Switch

The limit switch on a water heater is a built-in safety feature. It will shut the water heater off when it senses too hot water or the temperature rises above 180 degrees F. Therefore, bad heating elements, loose wiring, and bad thermostat are some caveats that cause the limit switch to trip. If the limit switch gets tripped, the pilot light won’t come on. 

How To Fix: 

I highly recommend you check the continuity of the limit switch. Don’t forget to press the limit switch in before testing it. If you are not electrically inclined, it would be best to hire a professional to inspect the limit switch and replace it if needed. 

03. Flammable Vapor Screen Gets Plugged

Most 0ften times, everyone overlooks the flammable vapor screen if they encounter the pilot light issues. But it can also be a reason behind this problem. A plugged or clogged screen prevents sufficient amounts of combustion air from going into the combustion chamber. And without air or oxygen, it’s impossible to light the pilot. 

How To Fix: 

Just clean the screen and reinstall it. Though it is pretty straightforward to tidy up the screen, you can find it a bit difficult to clean the rear. Once you clean the screen, light the pilot maintaining the manual guideline. If the pilot light still won’t come on, you should hire a professional.  

04. Faulty Gas Valve

If the limit switch is okay and the thermocouple doesn’t get bad, I bet the gas control valve is at fault. A defective gas control valve can’t supply the right amount of fuel to the combustion chamber. And without sufficient gas supply, you can’t light the pilot. 

How To Fix: 

Replacing the gas control valve is the only solution to fix the pilot light issues. Fortunately, I broke down the step-by-step guide on changing the gas valve in this article: Richmond Water Heater Gas Valve Problems. So, check out that article and make a replacement successfully. 

05. Pilot Thermistor Is Bad

A bad pilot thermistor can also cause the pilot light to go out. You can easily detect if the thermistor goes bad. Turn the gas on, and hold down the pilot light button. Then, light the fire and press the button for another 10-20 seconds. If the pilot light goes out when releasing the button, I am pretty much sure the pilot thermistor is at fault. 

How To Fix: 

Fortunately, the pilot thermistor is a cheap replacement. Just get a new one and install it. If you don’t know how to replace this part, call a professional.

06. A Tripped Thermal Release Device

Every gas water heater, including the Richmond Water Heater, has a thermal release device. You can find this device in the combustion chamber. Once you remove the burner assembly, you can see it right behind it. 

Thermal Release Button
*This is how the Thermal Release Button looks like*

Because of the thermal resistance device, the water heater can breathe. The air makes its way through the vents and oxygen goes into the combustion chamber. And the flame will be there where the burner is. 

If the thermal resistance device gets broken, the little glass bulb will pop. When the little pin comes through, it closes the vent and your heater can’t breathe. As a result, the pilot light won’t stay lit anymore. 

Igniting paint or stain fumes can cause the thermal resistance device to trip. 

How To Fix: 

You must replace the broken thermal release device to solve the pilot light issue. I recommend you watch the following tutorial for what to look for if you want to do it yourself. 

Alternatively, you can hire a professional plumber to do this replacement for you. In this case, you may need to spend $150 to $200 including the part and labor costs.  

07. Blocked Air Intake

Gas water heaters like the Richmond or others have an air intake screen. The air goes through the screen into the combustion chamber and helps the pilot light to stay lit. Without sufficient oxygen, you can’t light the pilot. And a blocked air intake means air can’t pass through it. As a result, the pilot light won’t come on. 

How To Fix: 

Unblocking the air intake of your water heater will be a pain in the ass. You need to pull the burner out and clean the air intake screen from inside. You can use a shop-vac to blow away dirt and debris from the combustion chamber as well as the air intake screen. 

Either way, you can use a bristle brush to clean around the water heater. Also, make sure you clean the base of the water heater as well. 


Every homeowner encounters the pilot light issues on their water heater. Luckily, I mentioned all the possible reasons behind this problem. So, what you need to do next is to follow the troubleshooting steps and figure out the source that keeps the pilot light from staying lit. Then, take the proper steps to solve the problem. Good Luck!

Read Also:

Richmond Water Heater Troubleshooting

Richmond Water Heater Reset Button

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