What is a thermocouple on a water heater?
A thermocouple is a tiny device found towards the bottom of gas water heaters.It measures temperature.These devices regulate the amount of gas that should pass through them in order for them to function properly.It then makes use of this process to heat up enough hot water to meet the demands of your home.
How does a thermocouple work on a gas fireplace?
The first is a small probe, about an inch long and 1/4 inch in diameter, positioned just above the pilot orifice in such a way that, when the pilot is on, the tip of the probe gets heated by the pilot flame. The other part of a thermocouple is a copper tube that connects to the front or side of the gas valve by means of a small nut.
How do I know if my water heater thermocouple is bad?
Assuming the pilot flame is at least an inch in height and burning blue, any reading less than 20 mV means the thermocouple needs to be replaced. If the water heater pilot won't light at all, or the flame is weak, make sure the gas is on, clear out the pilot tube with compressed air and perform the test again.
Should I Turn Off the gas before replacing a thermocouple?
As is true with any gas repair, it's important to work safely, and that means shutting off the gas before you replace a thermocouple. How Does a Gas Water Heater Thermocouple Work? Sorry, the video player failed to load. (Error Code: 100013) Where Is the Thermocouple?
How do you clean a thermocouple on a gas water heater?
In cleaning a thermocouple, you need some steel wool or 60-grit sandpaper, and a cloth. First, turn off the gas supply, unscrew the thermocouple and then clean it with steel wool or sandpaper then wipe down with a cloth to remove residue. I clean our thermocouple every six months to avoid getting it coated with soot.
Where is the thermocouple on a gas heater?
1:245:18Furnace - Thermocouple | Repair and Replace - YouTubeYouTubeStart of suggested clipEnd of suggested clipThis is the pilot assembly x2 the pilot is the thermocouple. If the thermocouple is dirty then itMoreThis is the pilot assembly x2 the pilot is the thermocouple. If the thermocouple is dirty then it won't warm up and won't produce enough voltage to open the gas valve.
What does a thermocouple on a gas water heater look like?
0:121:42How Does a Thermocouple Work in a Water Heater? | Repair and ReplaceYouTubeStart of suggested clipEnd of suggested clipAnd will ignite the main burner whenever heat is needed next to the pilot is the thermocouple whichMoreAnd will ignite the main burner whenever heat is needed next to the pilot is the thermocouple which generates a small electrical current when heated by the pilot flame.
How do I know if my thermocouple is broken?
After about a minute, when you're sure the probe has gotten hot, place one lead on the shaft of the thermocouple and the other lead on the connector. If the reading is less than 25 millivolts, the thermocouple is bad and needs to be replaced.
Can I replace a thermocouple myself?
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 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.
Do all gas water heaters have thermocouples?
Not all gas water heaters have a thermocouple. Some newer models have an advanced temperature control system. Essentially, it is a microprocessor that constantly monitors and controls burner operation and maintains consistent and accurate water temperature levels. The flashing LED indicates that the pilot is on.
How much does it cost to replace a thermocouple on a 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.
Can you clean a thermocouple and make it work?
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 happens when a thermocouple goes out?
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.
How often should thermocouple be replaced?
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 do you know when you need a new thermocouple?
A working thermocouple will give a reading of between 25 and 30 millimeters. If the reading is less than 25 millimeters, it should be replaced.
How do you replace a thermocouple on a gas heater?
How to Replace a ThermocoupleOpen the Access Cover. Remove the furnace's access cover. ... Remove the Old Thermocouple. Using an open-end wrench, unscrew the nut that holds the thermocouple end fitting into the gas control valve. ... Install the New Thermocouple. ... Connect the Gas. ... Turn on the Gas and Power.
How do you clean a thermocouple on a wall heater?
How to Clean a Pilot Light – A Step-By-Step GuideCut off the gas to your furnace. ... Remove the pilot light and thermocouple assembly. ... Use your pliers or wrench to remove the pilot light and thermocouple from the bracket.Using the wire brush, brush away the carbon buildup and soot from both components.More items...•
Why will my gas heater not 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.
Can you bypass a thermocouple on a furnace?
Realistically, you have just disabled the thermocouple, but you can also reach in and unclip it from its holding bracket where it meets the pilot light. In most cases it will be held on with a gravity clip, but some are held on with a screw that must be removed with a small screwdriver.
Introduction
A hot water heater that doesn't heat might just need a new thermocouple. Learn how to replace this inexpensive part and keep your hot water heater working for years to come.
Vacuum
This is a good time to vacuum out the burner compartment, check for water leaks and remove debris in the burner ports. Attach the thermocouple and reinstall the burner assembly. Light the pilot following the instructions on the water heater.
How to find thermocouple on water heater?
Locate the pilot light on your water heater or furnace and you've found the thermocouple. It consists of two parts. The first is a small probe, about an inch long and 1/4 inch in diameter , positioned just above the pilot orifice in such a way that, when the pilot is on, the tip of the probe gets heated by the pilot flame. ...
How to check a water heater thermocouple?
Connect one multimeter lead to the copper tube with an alligator clip and touch the other lead to the nut that connects to the gas valve. The nut must be disconnected from the valve when performing this test. Start the pilot, hold in the gas control to keep the flame lit and check the meter. Assuming the pilot flame is at least an inch in height and burning blue, any reading less than 20 mV means the thermocouple needs to be replaced. If the water heater pilot won't light at all, or the flame is weak, make sure the gas is on, clear out the pilot tube with compressed air and perform the test again.
Where Is the Thermocouple?
Locate the pilot light on your water heater or furnace and you've found the thermocouple. It consists of two parts. The first is a small probe, about an inch long and 1/4 inch in diameter, positioned just above the pilot orifice in such a way that, when the pilot is on, the tip of the probe gets heated by the pilot flame. The other part of a thermocouple is a copper tube that connects to the front or side of the gas valve by means of a small nut. You can remove the thermocouple by unscrewing this nut and unclipping the probe from the bracket that holds it close to the pilot flame.
What happens if the thermocouple on a water heater fails?
If the water heater or furnace thermocouple fails, you'll still be able to light the pilot, but it won't stay lit, and your gas appliance won't work.
What is the thermoelectric effect?
The thermoelectric effect that makes a thermocouple work is called the Seebeck effect, named after the German physicist who discovered it in 1821. The Seebeck effect works with any two dissimilar metals, but the ones most often used in gas water heater thermocouples are stainless steel and copel, which is an alloy of nickel and copper.
How Do I Know If My Thermocouple Is Bad On My Water Heater?
After a while, soot, dust, and dirt may settle on a thermocouple. This build-up is the leading cause of the thermocouple not detecting heat, thus, not working correctly. And this means that the sensor inside the unit gets improper readings.
How to clean a thermocouple?
This will help to maintain a clean sensing area for optimal performance when heating water later on. Check for corrosion between the terminal and the power wire and wipe it away before the cleaning process. Finish by wiping down the sanded areas with a new microfiber towel to ensure everything is in good working order.
When Should You Replace A Thermocouple?
You should replace your thermocouple when there is no hot water running or the readings on the multimeter are below 25 millivolts. You should also replace it if the build-up dirt on the thermocouple is beyond repair and impairs its function.
Can Water Damage A Thermocouple?
Water can damage a thermocouple. Although, the thermocouple will never contact water or moisture as it’s adequately covered.
What happens when the thermocouple wears out?
When the thermocouple wears out, the pilot stays off too. And consequently, the burner does not light, thus, not heating the water.
How to loosen burner plate on a gas heater?
Then proceed by loosening and removing the nuts that secure the burner plate. Turn the screwdriver a couple of times to loosen any threaded links connecting it to other components.
Why do water heaters need seismic straps?
Source Seismic straps are critical when using water heaters if you live in an earthquake-prone area. They prevent the water heater from tipping backward as the ground shifts. But there is a...
What is a Water Heater Thermocouple?
A water heater thermocouple is a sensor that turns off the gas supply when the pilot light goes out. This operational and safety feature is also known as a flame or heat sensor and its function is to control the flow of gas into the burner.
How Do You Know if Your Water Heater Thermocouple is Bad?
A bad thermocouple is the most common reason for a water heater pilot light that won’t stay lit. And it’s not unusual for it to wear out.
Final Thoughts
A gas water heater thermocouple replacement is a project you can do yourself. But it is important that you follow the safety rules: (1) turn off the gas is priority number one, and (2) don’t touch the thermocouple until it has cooled down.
Call 1-Tom-Plumber
Don’t hesitate to contact us here or call us at 1-Tom-Plumber (1-866-758-6237) if you need help safely maintaining, repairing, or replacing your gas water heater.
