Table of Contents
The thermocouple is part of the pilot burner assembly and connects to the gas control valve on the outside of the water heater. It is a simple device that converts the heat from a burning flame into a small electrical current, allowing it to work as a switch to control the flow of gas from the gas supply valve.
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.
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.
Where is a thermocouple located?
Your furnace’s thermocouple is usually located right in the flame of the furnace’s pilot light. Its copper tubing makes it easy to spot. The thermocouple is made up of a tube, a bracket, and wires.
Is it difficult to replace a water heater thermocouple?
Thermocouples are designed to detect a pilot light’s loss of heat and close the gas valve to prevent a gas leak. Replacing a thermocouple is a relatively easy fix that can take less than two hours.
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.
Can you bypass a water heater thermocouple?
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.
Why does my pilot light keep going out after replacing thermocouple?
If your water heater pilot won’t stay lit even after replacing the thermocouple, you most likely have a faulty gas control valve. It is a sign that the valve is failing to open and allow gas to flow to the pilot. You could also be dealing with a tripped or faulty thermal switch.
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 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.
How do you bypass a thermocouple?
To bypass the 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.
Do all water heaters have a thermocouple?
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 water heater thermocouple?
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.
What causes water heater pilot to go out?
Over time, thermocouples can malfunction, accumulate dust buildup, or the device can get bent away from the pilot light’s flame. In either case, the thermocouple will struggle to sense the pilot light and stop the gas supply.
Does an 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.
Who replaces thermocouple?
Honeywell, White Rodgers, and other manufacturers make universal replacement thermocouples, usually with a 30-millivolts (mV) rating for standing-pilot furnaces.
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 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.
