Updated on 10th May, 2023 by Martin Astley
Controlled by a PCB (printed circuit board), a boiler gas valve is a crucial component of your central heating system that controls the flow of oil and gas to the burner and the pilot light. It regulates and maintains the correct pressure for efficient operation, ensuring that the right temperature is reached with minimal waste of energy.
Modern boilers typically utilise electronic gas valves, which offer advanced features such as automatic shut-off in case of malfunction or insufficient gas supply. They can also be adjusted remotely based on sensor readings and temperature set points, providing fine control for optimal performance.
Gas valves must be maintained and checked regularly to ensure they work correctly. If this isn’t done, dangerous things like gas leaks or fires can happen. Therefore, trained professionals must handle all aspects of boiler gas valve repair and replacement.
But how do you know that your boiler’s gas valve is faulty? What are the symptoms of a defective boiler gas valve? This article will answer these questions, so continue reading!
How Does a boiler gas valve work?
Understanding how a boiler gas valve works is crucial for ensuring proper heating in your home. The gas valve on the boiler controls the flow of gases into the burner and pilot light, which are essential for igniting the boiler. When you press the heating and hot water buttons on your gas boiler, the PCB (printed circuit board) detects whether the fan is operational. The PCB is a critical component as it controls the gas valve, which adjusts the gas flow based on changes in thermostat settings and water usage.
However, if the PCB detects that the fan is not functioning correctly, the boiler will lock out, resulting in interrupted or no heating. Therefore, it is essential to regularly check and maintain the gas valve and fan to ensure optimal performance and prevent any potential issues. Understanding how the gas valve works and its importance in the heating process can provide you with a comfortable and warm environment in your home or workplace.
What are the reasons behind a faulty boiler gas valve?
Boiler gas valves can malfunction for various reasons. However, to troubleshoot a gas boiler valve, it is imperative to seek the assistance of a Gas Safe Engineer. Nonetheless, it is crucial to comprehend the underlying issues to determine when to contact an engineer. Below is a list of common problems faced due to a faulty gas valve on the boiler.
1. PCB Problem
The problem with the gas valve in gas boilers is a common one, and it frequently results from a printed circuit board (PCB) issue. The PCB oversees various boiler functions, including managing the temperature and pressure through sensors installed in the system. When a fault occurs in this component, it can disrupt communication with critical components such as the gas valve, causing it to remain closed regardless of heating demands or open even when there is no need for heat.
This malfunction can cause serious safety risks and reduce energy efficiency. Professional maintenance and repair should be sought to ensure that any issue with the gas valve or PCB is adequately resolved and to prevent future incidents by performing routine inspections and servicing.
Sometimes the issue is not only with the gas valve but also with the PCB. Before you decide to get your PCB replaced, consider getting yourself a new boiler or a boiler replacement if your boiler is more than 12–15 years old, as the replacement of the PCB costs a lot.
2. Sticking Valve
Facing a boiler gas valve problem due to sticking valves is common in heating systems that require careful attention. Various factors, such as dirt, debris, or corrosion in the valve mechanism, can cause sticking valves. Over time, these impurities gradually accumulate and cause the valve to stick or fail altogether.
Sticky valves may decrease the system’s efficiency, leading to higher energy bills. Timely inspection and maintenance of boiler gas valves are essential to prevent sticky valves and ensure reliable operation.
Regular cleaning and lubrication can help prolong the valve’s life and improve efficiency. It is highly suggested that if you face a problem related to your gas valves, you should immediately contact an expert. Experts have the capabilities and qualifications to ensure the safety of your home and central heating system.
3. Wire connection problem
Gas valve problems can also be caused by issues with the wire connection of your boiler, making it operate inefficiently.
The gas valve regulates gas flow into the boiler to ensure it operates safely and efficiently. Wiring problems, such as loose connections, damaged wires, or an incorrect voltage supply, can interfere with the valve’s operation and cause fuel supply interruptions, low heating levels, or possibly dangerous conditions.
It is crucial to promptly identify and address wiring problems by checking all loose and damaged connections and establishing proper electrical ground.
It is suggested that you get professional assistance from experts. They not only have in-depth knowledge about the components used in your specific boiler system but also have the capability to ensure proper installation while meeting local safety regulations.
4. A faulty gas valve
Sometimes the reason behind the gas valve problems is the valve itself. Especially if your boiler is old or beyond economic repair, in this case, you should contact a gas safe engineer. They will visit your site to check your valve and recommend whether to replace it or repair it.
5. Gas valve not closing
Another problem is that the gas valve doesn’t close properly. This indicates that gas is leaking into the burner of your boiler. You might notice a variety of fault codes if this is the case. These could be due to the gas valve getting stuck, letting by, or, more often, “flame detection,” even though there is no gas demand. A gas valve that is leaking gas is not safe. If you smell gas, the best decision is to shut off the gas valve, contact a Gas Safe engineer, and let him inspect the problem.
If you are having difficulty understanding the error codes, then for further details, we have a detailed guide on boiler fault codes for some famous brands:
- List of Worcester Bosch Boiler Fault Codes
- List of Glowworm Boiler Fault Codes
- List of Baxi Boiler Fault Codes
Replacement Cost of a Gas Valve:
The cost to replace a gas valve can vary depending on the location, type of valve, and complexity of the installation. Generally, the total cost includes both labour and materials needed for the replacement. Most residential installations’ average costs range from £180 to £220. Most of this cost is usually attributed to labour charges, as gas valves are intricate components that must be installed properly to prevent leaks or hazardous situations.
Sometimes the issue is quiet and only requires freeing a stuck valve to continue the boiler’s efficient operation, which might cost less than £100. And sometimes, the parts are expensive, and the overall cost may go up to £300.
Should I replace my boiler with a new one?
It may be wise to consider investing in a new boiler if issues with a gas valve arise due to the wear and tear of costly components such as the burner, heat exchanger, PCB, ignition leads, fan, and pump, and your boiler is ageing.
To ensure optimal functionality and safety, promptly addressing any problems with your gas valve is crucial. Neglecting these issues can lead to more significant and costly repairs down the line, as well as potential safety hazards.
Investing in a new boiler may seem daunting, but it can ultimately save you money in the long run by improving energy efficiency and reducing the need for frequent repairs. Also, modern boilers have higher efficiency ratings, which help you save money on energy bills and reduce your carbon footprint.
Get a new boiler
Get your new boiler and save your heating bill yearly with new energy efficient boiler.
I hope you can now deal with multiple gas valve faults and know when to contact a Gas Safe engineer. However, if you want to replace your boiler with a new one, we can help! Contact 24|7 Home Rescue at 0345 3192 247, and our team will help you find the right boiler according to your needs.