May 20, 2024 
Gas Stovetop Cooker Hob Repair Guide
In this repair guide, we will walk you through the dismantling of a gas burner top or hob and explain how each component works. The principles remain the same, whether you are using a bottle or natural gas and irrespective of whether the appliance is a countertop or freestanding.
Our guide includes common questions and faults that people have asked us about their gas stovetop hobs:
- gas hob not clicking 🚫🔊
- gas hob has a low flame 🔥➡️🔽
- gas hob not lighting 🚫🔥
- gas hob not staying lit 🔥➡️🚫
- gas hob not igniting 🚫🔥
- gas hob not sparking 🚫✨
- gas hob not working 🚫🛠️
We would recommend you watch our video since we’re showing related components and possible problems about gas hobs and cooker hobs.
Additionally, you can visit our web store to buy genuine spare parts: https://shop.how-to-repair.com/collections/cooker-oven-parts
Understanding the Gas Stovetop Components
Your gas enters the appliance via a rail to the gas valves. The number of these valves will depend on the number of burners on your appliance. The gas is then ignited either by a manual button that you press or individual switches which are activated when you turn the knob on. As you turn the knob, you’ll hear a clicking sound, indicating that the spark has been lit. These valves then regulate the amount of gas going through to the burner cup.
The burner cup has a small jet in it, the size of which depends on the size of the burner and the type of gas going to the appliance. In natural gas appliances, the jet will be bigger than in bottle gas appliances.
We suggest you watch our video to learn how to fix gas burner not lighting.
Understanding the Flame Safety Device (FSD)
The gas is controlled and made safe via the Flame Safety Device (FSD), which consists of three components – the gas valve, the spark, and the thermocouple. When you press the gas valve down, it allows the gas to flow to the burner head. If you release the gas valve before the thermocouple reaches the correct temperature, the gas goes out.
The thermocouple generates a small amount of millivoltage electricity when heated. This energy holds the gas safety device open once it’s at the correct temperature, allowing you to remove your hand from the knob and keep the gas lit. If the flame goes out due to wind or a spillage, the tip cools, stops producing electricity, and shuts off the gas supply, making the appliance safe.
Accessing the Gas Components
To begin, remove the griddles, burner caps, and tops. This will expose some screws. Please note that these screws can become quite stiff on used appliances due to corrosion caused by electrolysis from dissimilar metals. To loosen these screws, we recommend you tighten and loosen them a bit at a time, potentially using WD40 for assistance. Always remember to turn off the gas and electricity to the appliance before starting.
After removing the screws, take off the knobs. Be careful not to damage the electrodes. Depending on the appliance, you may need to remove mounting bolts from underneath the appliance.
Gas Hob Ignition System
Firstly, we’ll tackle the ignition system. In some appliances, there is an ignition button that you press when you turn on a gas valve. However, since 2008-2009, there has been an increase in safety systems on appliances.
These safety systems work such that when you turn the knob, it activates an individual switch that ignites the burner. These systems are also equipped with a Flame Safety Device – the gas valve will not open unless the ignition switch is activated.
If you face issues with the ignition system, the most likely cause is a faulty spark generator or ignition switch. You would need to replace these components.
First, disconnect the wires from the faulty spark generator and connect them to the new one, ensuring the wires match up correctly. Similarly, for the ignition switch, remove it from its holder, disconnect the wires, and replace it with the new one.
On the other hand, over time, the burner cup can become blocked with food residues and grease. This can lead to uneven flame. To clean it, remove the burner cup and soak it in a solution of warm water and dish soap. Use a brush to scrub off any stubborn dirt. Rinse it thoroughly and let it dry completely before reassembling.
Maintaining and repairing your gas stovetop can extend its lifespan and ensure optimal performance. However, always remember that working with gas appliances requires caution and expertise. If you’re unsure or uncomfortable with any procedure, it’s always safer to call in a professional.
For all your gas appliance parts and more information on part names, you can visit our repair guide for a complete guide to understanding common faults.
Related Repair Guide: Gas Hob Not Lighting Or Igniting
Related Repair Guide: How To Replace Solid Plate Elements On Hobs?
Related Repair Guide: How To Test Hob & Oven With Thermocouple?
1. Gas Stovetop Cooker Hob Repair Guide
5. Cleaning a Blocked Gas Jet on Cooker Hob
2. Accessing Gas Components of Cooker Hob
6. How a Thermocouple Works on Gas Burner
3. Gas Hob Ignition System
4. Gas Valve & Burner System Explained