A person standing on pipes under which the parquet is removed, attempting to feel if there is any warmth coming from them.

Underfloor heating has become one of the many wonders of the world. Not only does it remove the downside of radiators not heating up an entire room, but it is also much more economical and sustainable. However, if you've invested in one of these systems and find that it isn't heating up, this can become a bit disheartening.

But don't worry; it might not be a big issue at all. In fact, there might be an easy fix. Before you look at getting help from a professional, there are a few common causes and fixes you can consider yourself.

Continue reading to find out why your underfloor heating takes ages to heat up or isn't warming up at all and what you can do to fix it.

Key takeaways

  • Troubleshoot common underfloor heating issues by checking thermostat settings, bleeding the system, examining water flow, testing electrical components, and inspecting insulation.
  • Seek professional help if troubleshooting steps don't resolve the problem or if you're unsure about handling electrical components.
  • Ensure proper maintenance and repairs to enjoy the benefits of an efficient underfloor heating system and the comfort it provides.

Types of underfloor heating systems

A collage featuring a collector from which pipes of the underfloor heating system branch out, along with rooms with installed underfloor heating pipes.

Before we get started on determining the issue of your underfloor heating system, we need to determine what type it is. There are two main types of underfloor heating systems:

Water underfloor heatingElectric underfloor heating

Wet underfloor heating works in almost the same way as electric, however instead of cables or heating mats, it uses a series of pipes and tubes. When turned on, warm water will flow through these pipes, eventually heating up the area above. These systems are much more economical in the long run and are, therefore, better for heating up an entire property.

Electric underfloor heating is exactly what it says in the name. It is a central heating system that warms up a room from below through a series of cables or heating mats. These are installed underneath the floors, and when turned on, electricity flows through the system, and heat radiates upwards. These systems are best for individual rooms rather than an entire property.

Signs your underfloor heating system isn't working

Illustration of underfloor heating pipes with temperature sensor for cold spot detection.

Properties face various common underfloor heating problems, and they can lead to undesirable results. Here are some signs you might be facing that, apart from your underfloor heating not getting hot entirely, that indicate it isn't working:

Uneven heating

If you're walking across the floor of your property and you're finding that some areas are warmer than others, you might be suffering from uneven heating. This can be uncomfortable, especially if some areas are too hot that it burns the soles of your feet or you can't get as warm as you wish.

Cold spots on the floor

If there are places on your underfloor heating that are not warming up at all, these are known as cold spots. They are specific spots on the floor that remain cold at all times, even though the system is turned on. This makes it hard for the system to run at its full capacity and provide you with the comfort you want.

System not reaching the desired temperature

Suppose you're finding your underfloor heating taking ages to warm up and never reaching the temperature you've set on the thermostat. In that case, this is another indication that there's a problem with the system. It causes frustration and makes it hard to relax and feel warm enough during the colder months.

Unusual sounds or malfunctions

If you're sitting and trying to relax but hearing strange sounds coming from your underfloor heating system, this can be a sign of a problem. You might hear anything like clanking, banging, or hissing. If it is too loud and makes it hard to concentrate in your daily life, you must fix it.

Common causes of underfloor heating issues

3D illustration of broken underfloor heating pipes due to air pockets, indicating malfunction.

So, what might be causing your underfloor heating to not heat up? Here are some of the common causes to consider:

Air pockets in the system

Air pockets are spots of trapped air in your underfloor heating system and can be found anywhere throughout the series of pipes in a water floor heating system. The reason this common problem is bad is that they can disrupt the proper flow of water going through the pipes, which in turn disrupts efficient heat circulation for the space above.

If there are any air pockets in your hydronic/water system, you probably won't experience no heat at all, but at least uneven warmth. You might also experience reduced system efficiency, which means you could see higher electric bills even when the system isn't reaching the desired temperature.

Water flow problems in hydronic systems

Another problem that's specific to water/hydronic underfloor heating systems is a problem with the water flow. While air pockets like those mentioned above might cause this, there can be a number of reasons why the water isn't flowing properly. For example, the pipes might have built up debris, which stops the water from circulating properly.

If there is a blockage in the underfloor heating system, it will cause the same issues as air pockets. You might experience uneven heating or cold spots that lead to discomfort. If left for too long, it can also potentially damage the entire pump, meaning the whole system will need to be replaced.

Electrical issues in electric systems

If you have an electric underfloor heating system, the last two causes won't apply to you. However, if you are still experiencing minimal or no heat, it could be due to an electrical issue. If there is an issue with any of the electrical components in the system, this can lead to a complete failure of the underfloor heating and potential safety hazards on your property.

If you're not experiencing any heat at all, it might be because the electrical issues have led to a complete system failure. If there is uneven heating, it might be that only certain components have been targeted. Either way, if you have an electric system and are not experiencing much heat, you should get it fixed immediately to avoid any safety hazards.

Thermostat malfunctions

When your underfloor heating system isn't warming up, it might not even be due to the system below the surface at all. In fact, it could actually all be down to the thermostat not working. When there's a malfunction in your thermostat, it can make it harder to control the temperature of your system, and therefore, it won't be able to reach your desired heat.

Thermostat malfunctions can result in inaccurate temperature settings. For example, it might say that it's 23 degrees on the system, but it might feel as though it's only 15 degrees because that is what your thermostat has told the system.

Insufficient insulation

If your heating engineer promised you that your system would provide you with a certain amount of warmth and you're not feeling it, it could actually be due to not enough insulation. Either it wasn't installed adequately at first, or the insulation has managed to deteriorate or experience damage over time.

When your insulation isn't working correctly, it will reduce the overall energy efficiency of the underfloor heating system. This can lead to heat loss and cause uneven warmth throughout the property. You might also find that the heating times are much longer with insufficient insulation, meaning you can't get comfortable quickly.

Troubleshooting underfloor heating problems

Illustration of a man reviewing the plan of an electric underfloor heating system, trying to understand why it's not working.

If you are experiencing any of the above problems, how can you fix them? Depending on the type of UFH system you have, you can try various troubleshooting methods to bring your heating back to its optimal standard.

Check thermostat settings

If you believe that there is a problem with your thermostat and not the actual underfloor heating system, there are a few things you can do to try and fix it. First, start off by checking that the thermostat is actually set to the temperature you want. This might seem like an obvious step, but it is worth checking, just in case.

If the temperature is at your desired heat, then you want to ensure the thermostat is properly calibrated. If it isn't, this could be what's preventing the system from reaching the right warmth. If the settings are inconsistent, it might be worth trying to recalibrate the thermostat or replace it entirely.

Bleed the system to remove air pockets

For water systems, if there's a chance there are air pockets in the pipes which are preventing circulation, you should bleed your system. Start by turning off the system, as it can be dangerous to do this while it is on. You then need to find the bleed valve in each heating circuit of your system and open it to let the air out.

Allow an adequate amount of time for the air to escape. If possible, see if you can spot the water starting to flow consistently again. If you're feeling confident that you have dealt with the problem, close all of the valves and restart the system to see if it is operating efficiently again.

Examine water flow

If you have bled your water underfloor heating system and still aren't experiencing the desired heat, you should examine the water flow. You can do this by actually inspecting the individual pipes and seeing if any blockages are preventing the water from coming through. You should also check to see if the pump is operating correctly, allowing the water actually to go through the pipes in the first place.

The best thing to do in this case is to balance the whole water underfloor heating system to ensure water is being distributed evenly.

Test electrical components

For electric underfloor heating systems, there are different methods you need to try to troubleshoot any problems. The best thing to start with is turning off the system completely to ensure there is no electricity going through. You should then check the system for any damage or faulty heating cables or mats.

It's also a good idea to look and ensure that there are proper electrical connections and a secure voltage supply for the system. Once you've done all this, turn the system back on and test the thermostats and sensors for accuracy, double-checking whether it is a system or thermostat issue.

Inspect insulation

If you've gone through every possible check for your underfloor heating system and it still isn't working, then you need to check the insulation. Examine the insulation beneath the floor for any potential gaps or damage. If there is any, it's best to add or improve the right insulation material as needed immediately.

Go through any weak points your insulation might have to prevent as little heat loss as possible. This means no warmth will escape when the underfloor heating is on, so you can experience the system in full force.

When to seek professional help

3D image of a question mark symbol composed of water underfloor heating pipes on tiles, symbolizing uncertainty about when to call professionals for underfloor heating repair.

For any of the troubleshooting solutions above, getting help from a professional is always recommended. This ensures that the job is completed at a high quality, and you won't have the risk of the issue resurfacing again. It also helps prevent any potential hazards from occurring when doing the repairs yourself, such as when handling electrical wires and mats.

We only believe you should try to fix heating issues in your underfloor systems by yourself if you are confident you have the complete know-how and expertise. However, if you have completed all the recommendations above and your system still isn't heating up or working, you should still contact a professional and consult them anyway.

Final thoughts

Underfloor heating systems are becoming increasingly popular each year, especially with the benefits they offer, from energy efficiency to better heating across larger areas. However, it can be a bit disheartening if the system isn't heating up properly and you can't experience the comfort you deserve.

Often, many easy fixes can help you relax and enjoy the warmth again, and Next Level are always here to help. We have an expert team of engineers who are always ready to assist, maintain, and repair when needed. All you need to do is contact us, and we'll attend to your underfloor heating system as soon as possible.

Collage showing underfloor heating system installation; craftsman pouring concrete screed over pipes on the left, completed result on the right.

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