How does Underfloor Heating Work?

Underfloor heating is becoming increasingly popular, and not just in individual rooms but across entire homes.

We can understand why. There’s a feeling of luxury that comes with underfloor heating but, more importantly, having the heat spread across the floor rather than concentrated into a single radiator (or other source) can help to save both energy and money.

Below we will look at the two most common forms of underfloor heating, water (also known as wet) and electricity, to help you better understand how they both work.

How does Underfloor Heating Work?

Underfloor heating is simply a network of pipes laid underneath the floor of a room (or multiple rooms). These pipes then heat up, in the same way as radiators, and this heat radiates through the floor and naturally rises throughout the room.

In some cases underfloor heating can be 10-20% more efficient than traditional radiators. However this efficiency doesn’t always necessarily mean cheaper costs, as homeowners will need to factor in the initial installation costs.

The pipes are typically laid in spiralling patterns, in order to cover as much surface area as possible, and are then covered in what’s known as a “screed” which is a liquid mortar that sets in a smooth surface (to allow for flooring on top) and helps to regulate and transmit an even temperature across the floor.

Water Underfloor Heating (Wet Underfloor Heating)

Setting Up

Underfloor heating is essentially like a large radiator underneath the floor instead of against the wall. Whether electric or water powered, the mechanisms and infrastructure are the same as they would be for traditional radiators.

The only caveat is that you need to ensure your floor is suitable for underfloor heating. If pipes are buried too deeply, or sit beneath particularly thick tiles or floorboards you will waste energy and money, as more will naturally be required.

Step 1 – Boiler

The first stage of your underfloor heating begins with the boiler. Almost all homes will use a boiler as the main source of central heating.

In most homes, the boiler is either oil or gas-powered and uses a form of fossil fuel. But, more homes are moving towards an electric boiler.

However, the concept is the same wherever your boiler gets its energy from. Water is heated up, and this hot water travels through the home via a network of pipes. With underfloor heating you are adding an additional (or replacement) network of pipes that sit underneath the floors of all or specific rooms within your home.

Step 2 – Getting the Temperature

Depending on where you live and the nature of the seasonal weather you experience, you will probably want the water to be hotter at certain points of the year and colder at other times. That’s where the thermostat comes in.

The thermostat acts as a link between two wires and, in doing so, allows you to control how hot you want your underfloor heating to be. Most thermostats are attached to the wall, and newer modern models can also connect to your phone as a smart device.

Step 3 – Wiring Centre

The wiring centre is like the control panel for central and underfloor heating. It controls the heating as it travels throughout your home.

For example, a cold room on the ground floor may require more energy and heat than a warmer room on the top floor. Or, rooms with underfloor heating may need less energy overall as the constant temperature is slightly higher in general.

The wiring centre controls what is known as the “zone valves”.

Step 4 – Zone Valves

The zone valve is just a valve that opens up and sends water from the boiler into the manifold. Its purpose is to obey the instructions from the wiring centre and separate the water for different rooms.

Step 5 – Manifold

The manifold is controlled by flow meters, which govern the flow of hot and cold water. Most people will set up their manifold when they first get their boiler.

In the blending valves (part of the manifold), hot water is combined with cold water to make it your desired temperature set at the thermostat.

Step 6 – Pump

The final step is getting the water to the underfloor heating. A pump will push the water to the room it’s supposed to be in and continue to pump it around the underfloor heating so the room becomes warm and raises or maintains a certain temperature.

Electric Underfloor Heating

In many homes with underfloor heating, the heat does not come from the boiler but from the mains electricity.

This heating is in the form of wires linked to the home’s electricity supply. It must be covered in a material that will allow heat to get through, won’t melt or burn, and won’t electrocute those walking over it.

When the heating is switched on, the mains supply the wire with enough electrical energy to cause them to become incredibly hot. This heat is then transferred to the floorboards, thus heating the room.

Like water-powered underfloor heating, electric underfloor heating also usually comes with a thermostat. This thermostat controls how much electricity goes into the wires. If you want a warmer room, turning up the thermostat causes the electrical flow to increase, which makes the cables hotter.

Naturally the opposite is also true.

If you want one room to be warmer than another, you will need to control the thermostat of each individual room. Hence, the temperature is regulated on a room-to-room basis rather than centrally, as it is with a water-based underfloor heating system.

Many modern homes and self-builds now come with underfloor heating as the idea of passive homes, and energy-efficient homes, become more popular.

We hope this helps in your understanding of underfloor heating, and for everything else home heating stick with