How to check and replace the thermocouple for a gas stove

Maintaining the correct operation of your gas stove is necessary for a cozy and secure living space. The thermocouple, a tiny sensor that determines if the pilot light is lit, is an essential part of a gas stove. The pilot light may abruptly go out and the stove may not ignite correctly as a result of a malfunctioning or defective thermocouple. We’ll walk you through the steps in this guide to maintain dependable and efficient operation of your gas stove by inspecting and replacing the thermocouple.

Understanding the thermocouple’s function in the operation of the gas stove is important before you begin the process of checking and replacing it. The thermocouple is essentially a safety mechanism that cuts off the gas supply when it senses that the pilot light is out. By doing this, the possibility of a gas buildup is avoided, which could be extremely dangerous. Your gas stove will function smoothly and safely if the thermocouple is routinely inspected and maintained.

A common sign that the thermocouple needs service is if you’re having trouble maintaining the pilot light’s illumination. An intermittent failure of the pilot light to extinguish quickly after ignition may indicate a thermocouple malfunction. Furthermore, if the burner flames seem weak or erratic, this might also be a sign of a thermocouple problem. Taking quick action to address these symptoms can help stop more issues from developing and guarantee that your gas stove will continue to function.

Let’s now examine the procedures for inspecting and changing the thermocouple. Even though it might initially seem overwhelming, with the correct direction and resources, this task is actually fairly manageable. Obtain the required tools before beginning, such as a wrench, a replacement thermocouple that fits your stove model, and any additional tools the manufacturer suggests. Furthermore, make sure the stove’s gas supply is off to avoid mishaps while performing the task.

You can start the process of checking and replacing the thermocouple once you’ve gathered the required tools and made sure the gas supply is off. This usually entails finding the thermocouple close to the pilot light assembly, taking it out of its mounting bracket, and disconnecting it from the gas line. The replacement thermocouple can be installed by following the same procedures after the old thermocouple has been carefully removed. To prevent any damage, it is essential to handle the parts carefully and make sure they are positioned correctly.

Why do you need a thermocouple?

Protective systems, in which a thermocouple serves as the primary temperature sensor, are used today to create safe operating conditions for gas stoves with an open flame.

When the burner’s gas supply is open during gas combustion, the high temperature creates TEDD between the primary sensor’s contacts. The fuel supply is cut off when the torch is disconnected from the burner, causing the gas flame to go out, the thermocouple to cool down, the TEMP to vanish, and the gas valve to close due to spring action.

A thermocouple is part of the gas control system found in many contemporary Western gas stoves. Users also report that, when it is completely unnecessary, the system frequently falsely triggers and cuts off the gas supply.

The thermocouple specifically triggers and turns off the gas when liquid gets on the gas stove or there is a draft in the kitchen. Consequently, owners of contemporary gas stoves must comprehend how the safety mechanism works and know how to change the stove’s thermocouple in the event that it breaks down.

What is a thermocouple

The international standard defines the terminology of a thermocouple as two welded conductors of different alloys with opposite thermo-EDS signs, in relation to which the largest potential difference is produced.

Thermocouple device for gas stove:

• thermoelectrode, which has a "hot" junction of two different metal alloys, attached by a nut to the mounting plate next to the burner of the stove;
• An extension wire placed inside a copper tube that acts as a negative contact in parallel;
• positive terminal, protected by a washer made of dielectric material, installed in the body of the gas shut-off valve and secured with a nut.

Thermocouple characteristics for common gas stoves:

• Thermocouple for gas stove Hansa, country Poland, length – 45 cm, price – 950 rubles.
• Thermocouple for gas stove Indesit, country Italy, length – 45 cm, price – 800 rubles.
• Thermocouple for gas gas stove Gefest, country Russia, length – 45 cm, price – 700 rubles.
• Thermocouple for gas stove Bosch, country Germany, length – 55 cm, price – 902 rub.

Operating principle

In a thermocouple, the thermoelectric effect is produced at the intersection of two conductors composed of various metals and alloys that are joined to form a current collector ring. The potential difference is zero when the soldering zone liquids are equal.

A voltage proportional to the temperature delta will arise as soon as one of the ends is in a region of higher or lower temperature. For different alloys, the coefficient of this relationship varies.

The interconnected operation of the fundamental protection components forms the foundation of the gas control system’s operation principle:

1. The user by pressing, turning and holding the knob on the working panel of the gas stove, which has a built-in gas control system, opens the gas, which is ignited by the igniter.
2. In the burner zone, the temperature begins to rise, from the products of combustion, as a result of which the end of the sensor heats up.
3. Thermocouple in the gas stove gives an electric signal to the electromagnetic valve – cut-off valve.
4. The valve is in the open position during stable operation.
5. When the flame on the burner is extinguished in an emergency, e.g. due to spilled liquid, the thermostatic sensor cools down, the cut-off valve does not receive a signal from it, so the emergency protection is triggered and it closes, cutting off the gas supply to the burner.

The gas stove must be turned on within a specific amount of time after the protection is triggered because the sensor takes some time to heat up. It takes roughly 5 to 20 seconds to complete various modifications; in the interim, it is not possible to turn on the stove.

Usually, the thermo-electric sensor has one hot tip that is positioned close to the flame spreader. There are versions with two or three temperature control points. They are utilized in variously modified ovens.

One peculiarity of these multi-point sensors is that the shut-off valve will still close even if just one of them fails.

Varieties of temperature sensors

Thermoelectric sensors are made from a variety of noble and common metal alloys. For particular temperature ranges, specific metal categories are utilized.

Thermocouples are divided into several types according to the metal pairs that are utilized in their manufacturing. The most popular pairs for using with gas stoves are these ones:

1. Type E, production marking THCn, is made of chromel and constantan, for operating temperatures from 0 to 600 C.
2. Type J – alloy of iron and constantan, TZhK grade, for working temperatures from -100 to 1200 C.
3. Type K, mark TKHA, produced on the basis of chromel and alumel plates, for working temperatures from -200 to 1350 C.
4. Type L, brand TCK, produced on the basis of chromel and copel plates, for operating temperatures from -200 to 850 C.

K/L/J type TCA temperature sensors are typically utilized in the protection systems of gas-fired boilers, stoves, and boiler units. Noble metal alloy thermocouples are available for high temperature ranges that are feasible in power generation and metallurgical production.

Cleaning

Don’t replace the sensor right away if it stops signaling the shut-off valve; instead, check and possibly clean the thermocouple.

The following actions can be used to determine the specific sign of such a failure:

• Press the igniter button;
• the burner ignites;
• The torch burns, as long as the finger rests on the button;
• as soon as the hand is removed from the button, the flame disappears.

This indicates that the thermocouple is dirty. The thermostatic sensor’s end is positioned directly next to the flame and burner. It’s also near the flame-spreader at the chamber’s top in the oven. This section of the thermocouple ought to be devoid of any flaws, deposits, and soot.

Sandpaper should be used to clean the temperature sensor’s working area if it has soot buildup. Less heat energy is delivered to the sensor and less electromagnetic field is produced the more substantial the fouling layer.

It’s likely that the millivolts produced are insufficient to activate the shut-off valve. It is essential to examine the thermocouple’s performance if this action is ineffective.

Functionality check

In the event that the fuel supply to the appliance is cut off, you must perform revision, repair, and replacement of the temperature sensor by hand.

After that, the thermocouple repair procedures can be completed. Similarly, if the stove uses energy, the user must remember to unplug the power source.

When heated over a paraffin candle, a functional thermocouple for a gas stove should produce an EMF at a level of 20 mV after 30 seconds. The thermocouple has to be changed if this value drops.

For a gas stove to operate effectively and safely, maintenance is essential in any home. A crucial element to consider is the thermocouple, a tiny but important safety device. You can guarantee that your gas stove will continue to function and avoid potential hazards by doing routine checks and replacements on time.

It’s crucial to comprehend the function of the thermocouple before checking it. In the event that it detects a pilot light failure, the thermocouple functions as a safety feature by cutting off the gas supply to the stove. This system keeps gas from dangerously building up in your house. Therefore, it is a proactive step that every homeowner should take to regularly check the thermocouple for any signs of wear or malfunction.

Thankfully, replacing and inspecting a malfunctioning thermocouple is a reasonably easy procedure that doesn’t call for specific knowledge. To begin, turn off the stove’s gas supply and give it time to cool fully. Next, find the thermocouple, which is typically located close to the pilot light. Look for any indications of damage, corrosion, or a weak flame sensor. It is recommended that the thermocouple be replaced right away if any problems are found.

The thermocouple must be replaced by taking out the old one and putting in a new one in its place. Make sure the thermocouple you buy is appropriate for the model of gas stove you own. To ensure correct functionality during installation, carefully follow the manufacturer’s instructions. After installation, test to make sure the gas flow is restored as intended and the pilot light ignites.

Maintaining your gas stove on a regular basis improves safety and extends the life of the appliance. This includes checking and replacing the thermocouple when needed. Maintaining a well-maintained gas stove in your home can provide you with comfort and convenience, provided you are attentive and take quick action when necessary.

Our "How to check and replace the thermocouple for a gas stove" guide will take you through a series of easy steps to make sure your gas stove runs comfortably and safely. An essential safety component that determines whether the pilot light is on is the thermocouple. Your stove may not function properly or, worse, could be dangerous if it is malfunctioning. Initially, we will demonstrate how to test the thermocouple’s signal to see if it is malfunctioning. Then, if it becomes necessary, we’ll walk you through the process of safely replacing it to make sure your gas stove keeps your house reliably heated.

Video on the topic

Oven burner goes out, thermocouple replacement.

Replacing the thermocouple of a gas stove

Why does not work gas control on a gas stove?. How to repair gas control with your own hands.