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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 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 do I know if my thermocouple is bad on my 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.
How long does a thermocouple last on a water heater?
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.
How much is a new thermocouple for a water heater?
Thermocouple replacement cost on a water heater The cost to replace the thermocouple on a water heater is $100 to $325. The thermocouple detects whether the pilot light is lit and signals the gas control valve to turn on the gas flow. Thermocouple replacement is the most common repair needed for gas tank water heaters.
How much does it cost to fix a thermocouple?
It costs $150 to $250 to replace a thermocouple. It checks to make sure the pilot light is on. It will shut the gas off if it’s not.
What causes a thermocouple to fail?
METAL FATIGUE Like everything, thermocouples can’t stay new forever. 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.
What happens if thermocouple is bad?
Normally when the thermocouple malfunctions or isn’t working, it simply shuts off the gas to your heater. This is important, particularly if the pilot light is out, because it prevents harmful gas from leaking into your home.
Can you clean a thermocouple?
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.
How do you clean a thermocouple on a hot water heater?
Clean the thermocouple – using the emery cloth sandpaper, sand the ends of the thermocouple and then give it a finishing touch with the lint-free cloth. Hopefully, you can get to the ends of the thermocouple without having to detach it from the assembly, but you may have to do that.
Can I replace a thermocouple myself?
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. Then detach the thermocouple from the burner and take it with you to the home center or hardware store to ensure you buy the right replacement.
What is the job of a thermocouple?
Thermocouples are sensors used to measure temperature. It is a device used inside a gas furnace in Kansas, to assist the pilot light in keeping your furnace running and safe. It works rather like a fail-safe to keep unburned gas from accumulating and burning, exploding or causing another type of health risk.
Which is better RTD or thermocouple?
RTDs are superior to thermocouples in that their readings are more accurate and more repeatable. Repeatable means that users reading the same temperatures produce the same results over multiple trials.
Why does my gas water heater keep going out?
Thermocouple Issues If it senses that your water heater pilot light keeps going out, the thermocouple will shift off the gas supply to the heater. Over time, thermocouples can malfunction, accumulate dust buildup, or the device can get bent away from the pilot light’s flame.
How long should 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!Apr 19, 2012.
Why does my water heater flame 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.
Where is a thermocouple located on a hot water heater?
The thermocouple is part of the water heater’s burner assembly and is positioned next to the pilot light. It slides into a bracket and is held in place by a couple of clips. The thermocouple line runs outside the heater and is connected to the gas control valve, which is located on the outside of the tank.
Can you damage a thermocouple?
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.
How do you maintain a thermocouple?
A temperature indicator or recorder should be checked, either with a potential divider or a standard thermocouple at least once a month, whether it is used much or little. Terminals must be kept clean, insulation must be checked, and thermocouples themselves must be recalibrated.
What is the most common thermocouple failure mode?
The most common failure mode for thermocouples is for them to fail open, this is known as thermocouple burnout. Burnout can result from a variety of reasons including the thermocouple experiencing a temperature in excess of that for which it was designed, metal fatigue, and oxidation.
