What Are Signs Of Radiator Problems
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- Admin
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- Signs Of Radiator Problems, Why Your Radiators Are Not Working, Bleeding a radiator
- Posted date:
- 26-07-2022

What Are Signs Of Radiator Problems?
What are signs of radiator problems? We look at how to tell if your radiator requires an expert heating engineer to help fix your problem.
The Radiator Leaks
Radiators work by distributing heat (and water in some cases) throughout a structure in order to warm the property.
One of the biggest issues with older radiators is that they can begin to crack after many years of constant use. This will then lead to the radiators becoming inefficient very quickly and will require either a full radiator repair or a total replacement.
The most common indication of a cracked radiator is an accumulation of water on the floor around the installed unit.
Though it can sometimes be common for a radiator to release a small amount of moisture, a large puddle of water on the floor is an indicator of a totally broken unit. The majority of home radiators require an annual inspection as well as maintenance.
If your radiator is currently leaking then you should call an engineer or technician as soon as possible so they can take a look at the unit and see if it needs to be replaced.
The Radiator is Cold
A radiator that does not function as it is designed can cause all kinds of frustration and unnecessary stress within your home. Another common issue that can suggest a malfunctioning radiator is when the unit is cold while running.
There are several different issues that can cause this to happen, but the positive news is that most of these issues can be solved without needing to replace the unit. Older thermostats in radiators are almost guaranteed to break at one point or another, this means that it may be to replace the competent as a malfunction will render the unit worthless.
The condensate pipe is another area that can need some attention. This pipe can back up and freeze during the cold winter months and can require defrosting to restore the radiator's ability to heat properly. A cold radiator can also require the system to be bled. This is because too much air has built up in the unit.
The Radiator Overheats
This can be a horrible side-effect of a radiator going bad. In order to ensure that the unit is saved, quick and comprehensive action is necessary. A radiator will overheat when the flow is blocked, or there is a buildup of debris somewhere within the unit.
This can, unfortunately, result in the radiator wasting a lot of energy or cracking in the worst-case scenario. In order to minimise the chances of having to replace the unit, you should contact a qualified and trained technician at the first sign of the radiator overheating.
My Radiator Is Cold at the Top but Hot at the Bottom
If your radiator is not warming up at the top, then the chances are that there is air trapped inside the unit. It is easy to let the air out of the unit by bleeding the radiator with a radiator key. These can be purchased from DIY stores.
My Radiator Is Cold at the Bottom but Hot at the Top
This can be the result of sludge or rust blocking your pipes and radiator. It can be a tricky fix, so it is best to enquire for a Gas Safe registered engineer to take a look at the unit for you. The professional may need to power flush your entire central heating system in order to ensure the blockage is removed. Once the blockage has been dealt with, the engineer may add an inhibitor solution in order to stop buildups in the future.
My Radiator Is Making Strange or Loud Noises
Noisy radiators are usually not much of a concern. A clicking or ticking noise from the metal of the radiator is very normal. The sound is simply the metal expanding or contracting as the material warms up or cools down.
If the noise is coming from underneath the flooring, it is likely to be the pipes contracting or expanding.
You may also hear your radiator whistling occasionally if the water flow rate is too high. Try switching the radiator valve fully on. In most cases, this should stop the whistling.
Clanking, banging, and gurgling noises can sound very worrying but are usually caused by air in the radiator.
Bleeding your radiators can fix this issue. Some noises can be due to loose pipes under the floorboards. If you believe this may be the case, it will be best to ask a Gas Safe registered engineer to take a look at the issue.
Reasons Why Your Radiators Are Not Working
Air pockets in the radiator
If you have noticed that your radiator is cold at the top and some heat at the bottom, then this is an indicator of air trapped in the system. When this happens, the trapped air will take the space in the unit designed for hot water, preventing the proper circulation of the radiator.
To fix this issue, you will need to bleed the radiator. Unscrew the bleed screw using a radiator key until you can hear the trapped air hissing out. Keep this going until water begins to flow. Once you notice water, ensure the screw is properly tightened.
The radiator thermostat not working properly.
The issue can simply be that the valve for thermostatic radiator control has been switched off. If a higher temperature has been selected, it would not be unusual for the valves to be seized in a closed state. This can easily be checked by taking the top cover off the valve. A knurled nut is commonly used for securing the valve. This can be undone with a hand.
Ensure that you do not undo any other nuts found on the valve though, or you may end up with water pouring right out of the unit and onto the floor.
Once the cover of the valve has been removed, ensure that the centre pin can be easily moved up and down by a few millimetres. If the pin cannot be moved, it means that the pin has seized. Try tapping on the component to free it. If you are unable to do so, then you may need to substitute the valve completely. You should always have a professional do this.
Sludge, debris, or blockages
On rare occasions, you may notice that your radiator is cold at the bottom and yet warm at the top. This is a sign that there is some kind of blockage which has accumulated in the radiator.
Hot water is not able to circulate correctly because of the buildup at the bottom of the unit.
The most efficient way to deal with this issue is to seek help from a professional. An engineer will provide is known as a power flushing service. This is the process of removing debris from the central heating system that is stopping the unit from functioning as designed.
Some other signs of a power flushing service being needed are if certain rooms are colder than others, your central heating takes quite a while to warm up, or if you need to bleed your radiators frequently. If you do not have access or very limited access to hot water, then this can be a sign of sludge buildup.
Bleeding a radiator
- Firstly, you will need to turn off your heating. You cannot bleed a radiator when your heating is switched on, as the unit may be too hot to touch. It can also result in hot water spraying out of the unit.
- Use the radiator key to turn the valve at the top of the radiator. Attach the radiator key to the square groove in the centre of the valve, and twist the key slowly anticlockwise. You should hear a hissing noise. This is the trapped air escaping from the unit. We recommend using a cloth to catch any water that dribbles out of the unit.
- Retighten the valve once the hissing stops and only liquid is coming out of the valve. You should do this quickly to stop water from escaping.
- Now, you should turn the central heating back on.
- Be sure to check the pressure by looking at the gauge on your boiler. Bleeding your radiator can lead to pressure drops. If the pressure is too low, then you will need to top it back up. This should be done by using the tap or lever on your boiler. This is known as the filling loop.
- Check if your radiator is now heating up properly. If the heat is evenly distributed throughout the radiator, then you have fixed the issue.
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