Question: How Do I Know Which Thermocouple To Buy?

Are most 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..

Can you replace a thermocouple yourself?

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. … Then unfasten the three nuts that hold the thermocouple and the two gas tubes to the valve.

How do you check if a thermocouple is working?

Place one test lead on the side of the thermocouple and the other to the end that screws into the gas valve. If the thermocouple has proper continuity, a small resistance reading should be visible on the multimeter. Many multimeters also indicate continuity with an audio alert.

Can I 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.

Can I use any thermocouple?

Typically the thermocouple sensor is mounted right in the flame of the pilot light on gas fired heating equipment. But not all of these systems use a thermocouple. Some gas fired heating equipment relies on an electronic ignition to ignite the flame. Those devices generally will not use a thermocouple.

What’s the difference between a thermocouple and a thermocouple?

The main difference between Thermocouple and Thermopile is that the Thermocouple is a thermoelectric device and Thermopile is a device that converts thermal energy into electrical energy. … Thermocouples are a widely used type of temperature sensor.

Are 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.

How long does a thermocouple last?

one yearIn effect, new thermocouples were installed into contaminated tubes, causing the degradation of the sensors and generating greater than a 100°F shift in accuracy. In this scenario, thermocouple life, which should have been close to one year, was shortened to within a week.

Can a thermocouple be cleaned?

The best way to clean your thermocouple is to use either a piece of steel wool or the coarse side of a sponge to gently clean off any soot or other remnants. You can use a pencil eraser to clean between the threads of the screw that connects the thermocouple to the control valve of your system.

What is the difference between K and J thermocouples?

Whereas a J Type thermocouple is made up of iron and constantan, K type thermocouples are composed of a nickel/chromium alloy (chromel) and a nickel/aluminium alloy (alumel) which gives them much better protection against oxidation and acidity than the iron limbs of the Type J.

How many types of thermocouples are there?

four different classificationsThere are four different classifications of thermocouple pairings, most distinguished by a capital letter heading.

How do I choose the right thermocouple?

How to choose a thermocoupleDetermine the application where the thermocouple will be used.Analyze the temperature ranges the thermocouple will be exposed to.Consider any chemical resistance needed for the thermocouple or sheath material.Evaluate the need of abrasion and vibration resistance.More items…

What size thermocouple do I need?

Universal thermocouples come in lengths from 15 to 36 inches. An 18 or 24 inch will suffice for all residential water heaters using universal kits. Almost all older waters heaters and many of the newer style units with a sealed burner compartment and a viewing window will use this thermocouple.

What causes a thermocouple to go bad?

The presence of oxygen causes a reaction in the thermocouple that can wear down the part and make the wires become thinner and more brittle. Oxidation can be caused by a small amount of oxygen making its way into a sealed environment and reacting with the pure metal of the thermocouple.

Can you fix a thermocouple?

If the pilot remains lit, but the main furnace doesn’t stay lit, it’s time to replace the thermocouple. Replacement thermocouples are in stock at most hardware and home improvement stores. Because they come in different sizes, take your faulty thermocouple to the store with you so you can make a correct match.

Is there a difference in thermocouples?

Thermocouple vs. Temperature range: First, consider the difference in temperature ranges. Noble Metal Thermocouples can reach 3,100 F, while standard RTDs have a limit of 600 F and extended range RTDs have a limit of 1,100 F. … RTDs are also more stable and have better linearity than thermocouples.

Is it hard to replace a thermocouple?

If no flame is present, the sensor stops or prevents the flow of gas from the gas valve, thus preventing the dangerous situation of gas flowing into the appliance when there is no flame to burn it. Flame sensors and thermocouples are simple parts that wear out and fail over time, and most are easy to replace.

What does a bad thermocouple look like?

Before jumping to the conclusion that the thermocouple is at fault, look at the pilot flame. If it appears small and has an orange-yellow tinge, it may be too weak to heat the thermocouple. The likely problem, again, is an obstruction in the pilot tube.

Can a thermocouple be too long?

The length of a thermocouple has no effect on its measurement accuracy or its ability to transfer the signal to the instrument. In other words, thermocouples do not experience “voltage drops” or power loss along its length as a high current power line might possess.

Should the flame touch the thermocouple?

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.

Can a thermocouple work intermittently?

a safety device that has started to go bad, or has failed permanently. In this client’s case, the thermocouple was initially working intermittently, and then finally failed. … This allowed the gas to flow long enough to heat up the thermocouple and generate some electrical current flowing back to the gas valve.