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.
What can go wrong with a thermocouple?
- Gas flow. The thermocouple may be hampered by a clog in the gas line or some other issue which prevents the gas from reaching it. …
- Sudden loss of heat. …
- Loose wires.
Can a water heater work without 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.How much does it cost to replace a thermocouple 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.
Can a thermocouple be cleaned?
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 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.
Are thermocouples for water heaters universal?
Universal thermocouples, as the name implies work on most water heaters. They are available online and in home supply stores for a reasonable cost. The length and the thread type are the two concerns when purchasing one.How do you bypass a thermocouple?
- Move the tilts switch wire aside.
- Remove your thermocouple from the heater using an 8mm wrench.
- Pull the valve housing aside using your 13mm socket wrench. …
- Remove the valve using your pliers. …
- Put your thermocouple back into position.
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 onWhat causes water heater pilot to 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.
Does pressure affect thermocouple?
The absolute pressure effect on thermocouple EMFs at high temperatures was studied up to a pressure of 3.5 GPa until 1970 (Getting and Kennedy, 1970); however, after this study, there has been no substantial progress for more than 40 years.
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 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 does it mean when your pilot light keeps going out?
A faulty, misaligned, dirty, or damaged thermocouple is often the culprit behind your pilot light going out. The thermocouple is an automatic safety shutoff device that prevents the gas valve from opening if the pilot light is out.
Will a pilot light stay lit with a bad thermocouple?
A thermocouple senses the heat of the pilot and allows gas to flow to the burner. A bad thermocouple will shut off gas to both the pilot and the burner so the pilot light won’t stay lit.
How do you clean a thermocouple on a 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.
What's a thermocouple look like?
The thermocouple looks like a piece of metal tubing smaller than a soda straw. To find it, first locate the gas control box. This is the box that the main gas line enters, where you turn the gas on in the furnace. (On most furnaces, it also houses the button that you hold open or push to relight the pilot.)
Which type of thermocouple is best?
Type N – Nicrosil-Nisil: This thermocouple has very good thermoelectric stability, which is superior to other base metal thermocouples and has excellent resistance to high temperature oxidation. The Nicrosil-Nisil thermocouple is ideally suited for accurate measurements in air up to 1200°C.
Can I relight the pilot light by myself?
If your pilot light goes out, your furnace will not be able to produce heat because its burners will not ignite. Often, homeowners can relight the pilot themselves.
How much does it cost to relight a pilot?
Most service providers will charge a standard fee per visit that typically covers the cost to relight a gas water heater. This service call price can range from $80 to $100.
What is capacitance manometer?
Baratron capacitance manometers measure true pressure (defined as force/unit area). This means that the measurement is insensitive to the type of gas being measured. Other gauges, such as Pirani, thermocouple and ion gauges, do not measure true pressure and therefore their readings will be gas-type sensitive.
What is the thermocouple gauge?
The thermocouple gauge is one of a group of gauges working on the thermal conductivity principle. … The metal strip is heated by passing a current through it and its temperature is measured by a thermocouple. The temperature measured depends on the thermal conductivity of the gas in the tube and hence on its pressure.
What is Knudsen gauge?
Knudsen gauge is a type of manometer that works with the interaction of particles with a surface. Particles that interact with a hotter or colder surface will exert a force on that surface. … In order to measure Knudsen force, experimental work and numerical studies were done by Strongrich et al.
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!
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.
How much does it cost to have a water heater flushed?
How much does it cost to flush a water heater? If you’re not confident doing the job yourself, expect to pay around $100. This is really a minimal expense considering how damaging sediment can be for your water heater.
