A central heating system installed beneath the floor is known as underfloor heating. Installing one of these will allow you to add a touch of elegance to your home and free up a room if radiators are being replaced. 

To ensure that the entire room surface is cosy and evenly heated, UFH heats your floor at a low temperature. However, this is not their only advantage. Did you know that underfloor heating can reduce your energy costs by up to 25% compared to radiators? Its greater energy efficiency is the reason. After installation, it also needs little to no maintenance. 

The above factors are strong enough to consider combining your boiler with underfloor heating. In this blog, we’ll look at the options for connecting underfloor heating to your boiler and whether a new boiler is necessary for the in-floor heating to function.

Can a Boiler Run Underfloor Heating? 

It is possible to heat your floors with a boiler. A boiler can heat the water that warms your floor before it passes through the underfloor pipes to heat the space. For underfloor heating, there is no particular type of boiler required. You should be fine if you currently have a standard system or combi boiler. But for a boiler to work perfectly with the in-floor heating system, it might need to suffer a few simple modifications.

Gas Boiler

With a gas boiler, underfloor heating is possible. Nevertheless, some adjustments may be necessary depending on the kind of gas boiler you have. 

Underfloor heating will function perfectly if you have a traditional gas boiler existing. On the other hand, gas combi boilers will only require minor modifications. 

Combi Boiler 

A combi boiler can power underfloor heating. To ensure that your gas combi boiler can run your central and underfloor heating separately, you might need to install a two-port valve.

Your boiler could overheat if you run both systems simultaneously without this valve. A licensed heating engineer can do the installation of this component.

Electric Boiler 

Unlike radiators, underfloor heating doesn’t require high temperatures. The flow temperature in almost all underfloor heating systems is about 50 degrees Celsius. Because of these less stringent restrictions, you can use an electric boiler for underfloor heating or any other type of boiler. Even 6 kW of power can be plenty.

How Much (kW) Power Do You Need For Underfloor Heating? 

It might surprise you to know that when we talk about boiler size, we’re actually talking to the boiler’s power rather than its actual physical dimensions. A boiler’s “size” is actually its output rating, which is expressed in kilowatts (kW). 

Therefore, the concept is fairly similar for boilers, and “sizes” come in output ratings like 23kW, 45kW, etc. Each home will require a specific “size” of boiler to be powerful enough for the property’s specific needs.

A lot depends on the boiler’s size. Your hot water won’t become warm enough if your boiler is too ineffective for your home to heat up fully. On the other hand, if a boiler is overly powerful, your energy costs will unexpectedly increase. 

What kW Boiler Do I Need For Underfloor Heating?

Each household has a different minimum boiler size needed for underfloor heating. That makes it regrettably impossible to provide a simple response. There are a variety of factors that will influence what kW boiler you need, including: 

  • The type of flooring 
  • The type of boiler
  • The arrangement of your house.

As a general rule, determining the output rating (or size) that is best for your boiler may be done with a pretty straightforward estimation. In your home, allocate 1.5 to 2 kW of power for each radiator. For instance, you would require a boiler with at least 20kW of power if your home has 10 radiators. 

This estimate is only a rough guess because different types of boilers can call for a modification. It’s not a precise number; rather, it serves as a general reference to help you decide what is excessively low and excessively high. We have made the straightforward table below as a resource to assist with this. You can see the suggested size range for your home based on the type of boiler you have and the number of radiators you have.

Number of RadiatorsCombiSystemRegular
Up to 1024-27kW9-18kW9-18kW
Up to 1528-34kW18-26kW18-26kW
Up to 20 (and over)35-42kW27-40kW27-40kW

Contact Us

At JCW Underfloor Heating, our clients want the best and easiest experience when purchasing their UHF system. If you have any questions or queries, don’t hesitate to contact our friendly team for help!