The airlock is a situation in which air is trapped in your central heating system, which disrupts the flow of water, preventing hot water circulation into your radiators, leaving your radiators cold, and interrupting heating. This problem sounds simple, but it significantly impacts your central heating system. The central heating system is responsible for circulating hot water from your boiler to your radiators. If the air is trapped in between, it will restrict the water flow and derange your home’s temperature.
So, knowing how to clear an airlock in a central heating system is essential. Apart from that, symptoms of central heating air lock include heat loss in radiators, no hot water, cold spots in radiators, banging noise from your heating system, low boiler pressure, and inconsistent water flow. Airlock in water pipes and central heating system affects your winter peace and energy bills. The good news is that you do not necessarily require professional assistance to solve this problem; sometimes, you can solve it by yourself.
In this article, we will discuss what causes an airlock and how to clear an airlock in central heating systems and hot water systems. along with possible preventive measures to avoid future problems.
Causes of Airlock:
- The central heating system, as previously noted, oversees the distribution of heat and hot water throughout your home. The surplus water vapour occasionally produced by this process has a lower density than water, so it sometimes rises to the top of your system when heated. and it causes an airlock, resulting in your heating system not working.
- When the water in your central heating system is first filled, dissolved air that takes up much of the volume may be present. If the trapped air in the central heating system is not released within a few days, airlock problems may result. It is important to remember that occasionally the “air” causing these issues might not be air alone.
- If you haven’t added any corrosion inhibitor chemicals to your system, chemical corrosion can occasionally result in the formation of gases as part of the corrosion process. This kind of airlock may cause a wide range of issues with your central heating system, including a complete loss of warmth across your house and a lack of heat from specific radiators.
- Also, you can encounter an airlock in the heating system rather than in specific radiators, which might lead to a complete loss of heating due to your system being refilled improperly, typically due to filling the downstairs radiators. In contrast, the upstairs ones have not been shut off.
- Your central heating system’s flow and return pipes may occasionally run vertically on walls or in cabinets, with the direction of the flow varying from upward to downward. The air will typically be pushed out of the vertical pipe when the average flow direction is upward. Thus, this is not a problem. However, the air cannot be cleaned quickly while the water flows downhill. When you combine this with a reduced pump pressure, the conditions become ideal for airlocks to form, causing some or all of your radiators to fail.
How to remove the airlock from your Central heating system?
Now that you know the causes of the airlock in your system, it’s time to discuss how you can remove the airlock from your system. Clearing the air in a central heating system is a relatively simple procedure, but it should be done carefully to achieve the desired results.
Warm up your central heating system:
Run the heating system for at least 15 minutes to warm up your radiators and boiler.
Identity which radiators need bleeding:
Then recognise which radiator needs bleeding, spot the cold radiator, check for gurgling and bubbling sounds, or feel which radiators are cold from the top and hot at the bottom.
Shutdown your central heating system:
After that, turn off your central heating system for 25–30 minutes, allowing your radiators to cool down completely.
Cover the area around your radiators:
Before bleeding the radiators, place a towel cloth below them to catch excess water.
Locate the bleed valve:
Locate the radiator bleed valve, which is usually placed at the top of the radiator. Make sure your towel or cloth is placed below this valve, as the bleed valve is the source from which the water is released.
“Take extra care while bleeding the radiators as, at this point, the radiators will be hot, so if you touch them accidentally, there is a chance your hand can get burned.
Use a Radiator key:
Use the radiator key, attach it to the bleed valve, and rotate anticlockwise not more than half a turn. After doing this, you will hear a hissing sound, indicating that the trapped air is escaping. This will guarantee that all the trapped air has been released.
Let the water drain completely:
Hold the radiator key until you see or feel water pouring out. Let the water sputter and wait until there is a consistent stream. If the water colour is black, it may indicate that there is dirt buildup, which means you will need to powerflush your central heating system, plus you might also need a professional’s assistance.
Retighten bleed valve:
After this, tighten the bleed valve. This time, turn it clockwise. Ensure no more water is escaping, and try not to overtighten the bleed valve.
Bleed out all the radiators:
Repeat the process with all the radiators that were having issues.
Turn the heating back on:
Now turn your heating back on. Hopefully, the airlock in your system will have been removed. If not, the issue might be not just an airlock and something more complex that you will have to contact a professional expert; in that case, we can help.
How to remove the airlock from the Hot water system?
Stop the flow of water
Locate the stopcock valve, which is usually located beneath a kitchen sink; turn it clockwise and stop the water supply.
Drain the water supply
After closing the stopcock, it is time to remove the remaining water from your system. It is advised that if you have two or more floors, you should always start from top to bottom. Open all the taps one by one, and eventually, the water will drain out and no water will be left.
Drain out your toilet flushes
To completely drain the internal water supply at your home, drain the water from your toilet flushes by repeatedly flushing the toilets until there is no water left.
Turn on the taps slightly on
After draining out all the water completely, please turn off the taps and slightly open them up to allow a small amount of water to flow. This will allow the trapped air to pass out. As suggested before, start from top to bottom in your home. Then close the taps back off.
Restart the water supply
After thoroughly draining the water, it’s time to let water flow again through your taps by turning the stopcock back on by rotating it anticlockwise.
Turn on the taps
After restarting the water supply, turn off the half-open taps, then continue all of your home’s faucets at maximum flow to remove any last bits of trapped air. Please turn off all fixtures after the water is effectively flowing from them, and the system should be free of an airlock.
The airlock is an aspect that occurs naturally and cannot be prevented. But preventive measures should be taken to avoid the problem in the future. The preventive measures include inspecting your pipework to ensure there is no defect in the installation. Additionally, regularly bleed out your radiators to enjoy uninterrupted heating and hot water.
If, in some cases, the problem is still not solved and your heating system is still not working, Then it is advised to contact a professional. And if you don’t know whom to contact, then feel free to call 24|7 Homerescue on 0345 3192 247 and get immediate assistance.