Why Won’t My Radiator Heat Up?

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Radiators are essential parts of our homes. They provide us with heat, keeping us warm during winter. But, sometimes they don’t seem to work properly – and there can be a variety of reasons why that might be.

If you’ve clicked on this article, you might be wondering why your radiator isn’t heating up. As we’ve already mentioned, there are several reasons why radiators fail to function properly, but the main reason is usually due to a faulty thermostat.

If you suspect that your thermostat is malfunctioning, then you should call a professional heating engineer or electrician to fix it.

Needless to say, if you’re currently in this predicament and you’re not sure whether, or not, your thermostat is causing problems, here are some other possible causes and solutions. Whenever you’re ready, let’s jump right in!

Why Won’t My Radiator Heat up?

First, let’s take a look at some reasons why your radiator may not be heating up.

Your Radiator Isn’t Heating Up

The most common problem when it comes to radiators is that they aren’t working at all. This could mean that there is something blocking the flow of water through the pipes.

Your Radiator Hasn’t Been Placed Properly

This is less to do with the radiator not heating up, but more with it not efficiently heating the room. The issue is that your radiator hasn’t been placed correctly. For example, if your radiator has been installed in the wrong place, this will affect its efficiency.

If for example, it’s been placed next to a lot of glazing, it could be losing a lot of heat straight out of the window! Something else that is worth knowing is that radiators tend to have a worse performance when placed on external walls with poor insulation, as the heat is sucked straight into the cold wall.

Another issue is that your radiator could be undersized for the room that it’s in and cannot deliver enough heat into the room.

Your Thermostat Might Be Malfunctioning

If your thermostat doesn’t seem to be functioning properly, then it may be malfunctioning. In such cases, you should contact a professional heating engineer or electrician who can replace the thermostat for you.

Unless you have experience, you shouldn’t attempt to fix this yourself as it could cause more damage to the heating system…and that could be costly for you!

Your Water Pressure May Be Too Low

If your water pressure seems to be lower than it usually is, then you should increase it as this could be a reason why it’s not heating up. A low water pressure means that the radiator isn’t getting enough water to keep the temperature high. To solve this problem, all you will need to do is add more pressure to the boiler.

Your Radiator Needs Maintenance

Your radiator needs maintenance from time to time, so it could be the reason it’s not working properly. Perhaps the pressure needs to be readjusted. Also, you should regularly check the condition of the radiator to prevent it from rusting and deteriorating.

Not many people know or do this, but a radiator should be replaced every 25 years for best performance. This is one reason why many people choose to have underfloor heating installed or retrofitted, as a good underfloor heating system should have a good 300 year lifespan.

If you are interested in this definitely look at our WundaTherm system, which can be easily retrofitted and is great for new builds giving rapid response, on demand heat. With all the control of radiators and even greater energy saving benefits of a traditional UFH system.

Your Radiator Could Have Leaks

Why Won't My Radiator Heat up (1)

Leaks in your radiator can cause serious issues. If your radiator has leaks, then you should get them fixed immediately. Otherwise, you risk having water damage inside your home and it will affect the pressure in your heating system.

If you can see that your radiator is leaking, turn it off and seek professional assistance from a plumber, or consider replacing it yourself.

Steps to Take When Your Radiator Isn’t Heating Up

If your radiator isn’t heating up, follow the steps below to fix the problem.

Step One: Check Other Radiators

The first step is to check the other radiators to see if they are warming up. This will let you know if it is just an issue with the radiator, or whether there is a problem with the boiler or thermostat.

Step Two: Use A Bleed Key

The next step is to use a bleed key on the affected radiator, as this will let out any collected air so that the hot water can spread evenly through the radiator panels. Just ensure that before you bleed the radiator, you have made sure that the heating is off and the thermostat and boiler is not pumping. If the heating has been on, then let the radiators cool down before tackling any bleeding problems.

Step Three: Check Boiler Pressure

Then, you are going to want to check the boiler pressure. If the pressure is too low, then the hot water will not be able to flow around the heating circuit. The correct boiler pressure is typically 1-2 bar, but you should check your own boiler manual. Once you have bled the radiators, it is necessary to then top up the boiler pressure.

Step Four: Check Your radiator valve

Check the thermostatic radiator valve or lockshield valve on your radiator to see if it’s working properly. If it’s not, then you should call plumber to fix it for you.

Step Five: Check The Boiler Pressure

Boiler Pressure plays an important role in the performance of your radiator. Make sure that the Boiler Pressure is sufficient so that your radiator heats up quickly.

Step Six: Clean Out Your Radiator

Clean out your radiator for any blockages. This way, you’ll be able to get rid of any clogs and blockages impacting your radiator’s ability to get hot.

Step Seven: Check The Pipes

You should check the pipes attached to your radiator to make sure that they’re not leaking. If there is a leak, then you should seek the help of a plumber.

Step Eight: Check The Connections

You should check the connections between your radiator and the wall. If they don’t look good, then you should seek assistance from a plumber who will be able to safely assess the problem for you.

Step Nine: Replace/ Clean The Filter (If Your Heating System Has One)

A dirty filter can reduce your radiator’s efficiency. So, you should replace your old filter with a new one. This is relatively easy to do, and shouldn’t require the help of a plumber.

Step Ten: Turn Off The Hot Water Supply

If nothing seems to be working, then you should stop trying to figure out what’s going wrong and instead isolate the radiator by turning off the valves, using decorators caps if necessary.

Step Eleven: Call A Professional

Though this one should certainly go without saying, we still think that this is a very important point to note.

After troubleshooting with the steps we have provided you with above, if you’re still unable to get to the bottom of why your radiator isn’t heating up, then you should immediately call a professional plumber to repair your radiator and determine what the issue is that is causing your radiator to be unable to heat up as it normally would.

Wrapping Up

Thank you for taking the time to read through this guide, we hope that it has been a help in determining some possible reasons why your radiator might not be heating up currently! We also hope that you found our guide helpful in learning how to diagnose and fix your own radiator problems as they arise.

Nevertheless, if, after troubleshooting with the advice we have shared above, your radiator is still not working – then you should be sure to contact a plumber for their professional assistance and service.

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