How much is a thermocouple for a hot water heater
Emily Carr
Updated on May 09, 2026
1 cause of pilot lights that won’t stay lit is a worn-out thermocouple. It’s easy to replace and a new one costs $5 to $10. Rather than trying to unfasten the thermocouple inside the water heater’s burning chamber, it’s easier to remove the whole burner and thermocouple assembly.
How much does it cost to replace a thermocouple on a hot water heater?
Thermocouple – $20 to $150 The thermocouple is an apparatus that senses whether the pilot light is lit and triggers the gas control valve. Repairs typically cost about $150 to have it done professionally, though a new thermocouple itself only costs about $20 on average.
How do you know if you have a bad thermocouple?
If you can’t get the flame to light at all, and you’re sure the gas is on, there’s probably an obstruction in the pilot tube. If the flame lights and goes out when you release the gas control knob after holding it in for the recommended 20 to 30 seconds, that’s the sign of a thermocouple malfunction.
How much does a plumber charge to replace a thermocouple?
Calling a professional plumber to install a new thermocouple should only be up to $150. If you do the work yourself, you will only pay the price of the part which is about $20. The thermocouple is responsible for sensing that the pilot light is lit and triggering the gas control valve to continue providing gas.Can you clean a thermocouple on a water heater?
You can use Emery cloth sandpaper to gently clean any debris or build-up from the end of the thermocouple. If present, you should also clean off any corrosion where the power wire connects to the thermocouple terminal. Be aware, you may need to detach the thermocouple from the burner assembly to clean it thoroughly.
How many years does a water heater last?
It would be nice to know when the time is right to replace your water before it springs a leak and causes an inconvenience or worse yet, damage to your home. Typically a residential hot water heater lasts between 6 and 13 years. Beyond 12 years, you are on borrowed time!
Can I replace a thermocouple myself?
The No. 1 cause of pilot lights that won’t stay lit is a worn-out thermocouple. It’s easy to replace and a new one costs $5 to $10. Rather than trying to unfasten the thermocouple inside the water heater’s burning chamber, it’s easier to remove the whole burner and thermocouple assembly.
What causes a thermocouple to go bad?
Changes in temperature can cause regular expansion and contraction in metal, which will cause thermocouples to weaken over time. After enough time, metal fatigue can cause a thermocouple to break. … If thermocouples start to give out unusual readings, it may be suffering from metal fatigue.How often do thermocouples need to be replaced?
How to Tell if You Have a Bad Thermocouple? Thermocouples can last up to 10 years if properly installed and maintained, while furnaces can last 15-20 years, although either may wear out sooner in multifamily units.
Why does the pilot on my water heater keep going out?The most common reason that your pilot light on your water heater keeps going out is a damaged, bent or dirty thermocouple.
Article first time published onWhy would a gas water heater pilot go out?
Some of the most common reasons that water heater pilot lights go out include: A faulty thermocouple. … Over time, thermocouples can begin to malfunction and shut off the gas supply to the pilot light even if it’s burning properly. A bent or dirty thermocouple.
What are signs that your hot water heater is going out?
- Water leaking from the heating tank. …
- Age of the water heater. …
- Running out of hot water quickly. …
- Inconsistent water temperature in the shower. …
- Discolored water coming from faucets. …
- Unusual noises coming from the water heater. …
- Lower water pressure.
How do I know which thermocouple to buy?
You want to get one that is about the same length as the one you have. They are sold in in 6″ increments for the shorter lengths, 18″, 24″, 30″ and so on. For a water heater, 18″ and 24″ are common, although longer ones are possible. Remove the old thermocouple and measure it to see what length you need.
Are thermocouples universal?
Honeywell, White Rodgers, and other manufacturers make universal replacement thermocouples, usually with a 30-millivolts (mV) rating for standing-pilot furnaces. … Electronic flame sensors are much less universal, and you must find the exact part specified for your furnace model.
How much does it cost to replace 40 gallon water heater?
Water heater costs by gallon A standard 40-gallon water heater costs $330 to $1,500 for the unit alone, or $500 to $2,500 including installation labor. *Price for tank unit only, not including installation.
What should it cost to replace a water heater?
Hot Water System TypeAvg. Hot Water PriceAvg. Hot Water Installation CostSolar Hot Water System supported with Electric Power$3650 to $5050+$2050 to $3550Solar Hot Water System supported with Gas$4950 to $6550+$2050 to $3800Heat Pump System$3350 to $4050$1050 to $2550
How long does it take a plumber to install a water heater?
How Long Does the Installation Take? A certified plumber should be able to remove your old water heater and install the new one in approximately three hours. This time frame is under normal circumstances and with no unforeseen issues occurring.
Does cleaning a thermocouple help?
Yes, you can clean a thermocouple, but the task must be done with a light touch. Remove the thermocouple from the process assembly, using a steel wool or emery cloth, lightly clean the tip removing any build up. Cleaning a thermocouple is not a fix for an issue, such as inaccurate readings.
What is a thermocouple on a hot water heater?
The thermocouple is a thermoelectric device that shuts off the gas supply to the water heater if the pilot light goes out. Its function is simple but very important for safety. The thermocouple generates a small amount of electrical current when it has been heated by the flame.
How do you stop a hot water heater pilot from blowing the wind?
You can prevent a faulty pilot light from wind by fixing your thermocouple, gas release, protecting against downdrafts, capping your chimney, and checking your firebox cover.
What does it mean when your pilot light won't stay lit?
If your pilot light won’t stay alight, it might be the thermocouple. Sometimes dust buildup collects on the thermocouple and blocks the sensor. Try cleaning the thermocouple and then relighting the pilot light. If it continues to go out, the thermocouple might need to be replaced.
How do you clean a thermocouple?
The best way to clean your thermocouple is to use either a piece of steel wool or the coarse side of a sponge to gently clean off any soot or other remnants. You can use a pencil eraser to clean between the threads of the screw that connects the thermocouple to the control valve of your system.
Can you use water without water heater?
Yes, with a few caveats. Is there a shutoff valve present on the cold water line to the water heater? If so, just turn it off. But be aware that if water passes through any fixture in the house you could end up with water spewing out of the hot water line where the water heater goes (known as backfeeding).
Should I replace my 15 year old water heater?
Anyway, you should consider replacing your water heater if it’s about 6-12+ years old and when you start running out of hot water faster. However, age and lack of hot water aren’t everything. You could have a 15-year-old water heater that works just fine and wouldn’t need replacing.
How long does it take for a 50 gallon hot water heater to heat up?
A 50-gallon hot water heater with 5,500-watt elements set to 120 degrees takes about 1 hour and 20 minutes to heat water coming in to the unit at 60 degrees. Conversely, when the water entering this same tank is 40 degrees, it takes 1 hours, 47 minutes to heat it up.
How do you know if your thermocouple is bad on your hot water heater?
If the pilot lights but the flame goes out as soon as you release the button after holding it for 60 seconds, then the thermocouple is bad. It’s possible to replace the thermocouple without removing the burner assembly, and many repair people do this.
Do Thermopiles go bad?
Like the other component parts in your furnace, the thermocouple can wear down over time, producing lower voltage than it should when heated. And the worst part is that you can have a bad thermocouple without even knowing. Therefore, inspecting and testing your thermocouple should be part of your furnace maintenance.
Does electric water heater have a thermocouple?
Not all water heaters use a thermocouple. Some of the more recent models use a mercury sensor to shut off the gas valve. An electric water heaters don’t use gas at all, and therefore doesn’t need any kind of emergency gas shut off. Thermocouples can fail and require replacement.