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Quick Answer: How To Replace Thermocouple On Water Heater

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.

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.

How do you know if your water heater thermocouple is bad?

A worn out thermocouple is one of the most common gas water heater problems. When thermocouples wear out, the pilot light goes out, the burner won’t light, and you will have no hot water.

How much should a plumber charge to replace a thermocouple?

Hot water heater repair cost Service Average cost to repair Leak repairs $100 – $1,000 Pilot light replacement $50 – $200 Pressure relief valve replacement $50 – $300 Thermocouple replacement $100 – $325.

Are water heater thermocouples universal?

Universal Thermocouples. 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.

Who replaces thermocouple?

Honeywell, White Rodgers, and other manufacturers make universal replacement thermocouples, usually with a 30-millivolts (mV) rating for standing-pilot furnaces.

How much does a thermocouple cost for 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.

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 when thermocouple goes 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.

How do you diagnose 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 you troubleshoot a thermocouple?

Importantly, always make sure the tip of the thermocouple is directly in the pilot flame. If the tip is in the flame, you have held the nob on the gas valve down for longer than a minute, the pilot flame is strong and steady, and the pilot still does not stay lit, then you likely have a problem with the gas valve.

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.

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.

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.

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.

Are thermocouples interchangeable?

Commercial thermocouples are interchangeable, economical, and supplied with standard connectors. Unlike most other temperature measurement devices, external form of excitation is not required for thermocouples because they are self-powered.

How do I choose a thermocouple?

How to choose a Thermocouple Determine the application where you will use the thermocouple sensor. Determine the temperature ranges the probe will be exposed to. Determine how important a fast response time is. Consider any chemical, abrasion or vibration resistance. Consider any installation requirements.

Are furnace and water heater thermocouples the same?

While most furnaces and boilers have a thermocouple, in some boilers and gravity furnaces a thermopile (pilot generator) will generate electricity to operate the gas control valve. You can distinguish this device from the metal tube of a thermocouple by the two wires in sheathing that lead to it.

How do I know what kind of thermocouple I need?

A thermocouple should exhibit very low resistance. Attach the negative lead to the red wire, and the positive lead to the yellow. In this case, the reading will be about three ohms. Thus we can conclude that this sensor is a thermocouple.

Is a flame sensor and thermocouple the same thing?

People tend to use the terms “flame sensor” and “thermocouple” interchangeably. In truth, while they basically perform the same job, they’re not the same thing. If your furnace uses an electronic controller, it’s got a flame sensor. Thermocouples are used on standing pilot furnaces that have pilot lights.

Should thermocouple be in pilot flame?

The pilot flame should touch the thermocouple at a specific level. If the flame is blue and weak, and barely reaches the thermocouple, it needs to be stronger. If it extends well above the thermocouple, it’s too strong. Install a new thermocouple by screwing it in, heating it up a bit, and then lighting the pilot.