The difference between electric & water underfloor heating

Published: 11th March 2020 Read time: 6 minutes
Underfloor Heating

Great start, you have considered underfloor heating as part of your project. Underfloor heating is a solution that is cost effective, environmentally friendly and a little touch of luxury!

Underfloor heating provides an even distribution of heat around the room whilst freeing up walls from radiators.

When selecting an underfloor heating system, the first consideration is an electric or water based system. As you will imagine, an electric system includes a 2mm heated cable that radiates heat into the floor covering (i.e tiles), which heat the room. Water systems pump warm water from the primary heating system (ie. the boiler) under the floor covering again radiating heat into the room. Each system can include a number of zones, where temperatures can be individually controlled by digital or wifi thermostats.

Each system has its benefits, and in this article today we are going to look at both in a bit more detail to help to provide guidance through your decision making process.

What is the size of the room(s) that you would like to heat?

The size of the heated area is fundamental when deciding between electric or water underfloor heating. Electric underfloor heating products start from 0.5sqm. Water underfloor heating systems start from 10sqm. Where the area is <15sqm electric underfloor heating is typically more suitable for the project (for example, bathrooms or kitchens) and for rooms >15sqm water underfloor heating becomes the better option.

The reason for this is the balance of the cost of the products and installation versus the cost of running the system. As the area gets larger, the water system becomes a lower cost solution.

Which is more expensive out of Water or Electric Underfloor Heating?

To answer this question, we must consider the cost of acquisition, the cost of installation and the running costs.

The cost to purchase electric or water underfloor heating systems

For areas <15sqm, electric underfloor heating systems are cheaper to purchase. As the size of the area increases above 15sqm water underfloor heating becomes cheaper than electric underfloor heating to purchase.

The cost to install electric or water underfloor heating systems.

The cost to install water underfloor heating systems is typically higher than the cost to install electric underfloor heating systems.

To install an electric underfloor heating system is very simple and can be completed within as little as 30 minutes. The system can be laid following the product instructions by anyone within minutes. Connecting the product to Mains (voltage 230/240v) must be completed by a suitably qualified person to conform with IEE Edition Part P Regulations, but does not take long.

To install a water underfloor heating system requires plumbing experience, but not necessarily underfloor heating installation experience. The installation can take one to three days, depending on the size of the area. It is not recommended to commence such a project without such plumbing experience.

The cost to run electric or water underfloor heating systems

Water underfloor heating is cheaper to run per sqm than electric underfloor heating systems. Water systems are heated using the primary heating source in the property (ie. Gas Boiler) and are typically cheaper to run that heating your home with radiators. Water flows through the system at 35’C – 60’C, being a lower temperature than domestic radiators (45’C – 80’C). Alternative heating sources (ie. Heat Pumps) can help lower the running costs even further.

Electric underfloor heating systems are more expensive to run, but for areas less <15sqm the incremental cost is very small. The growing popularity of Solar PV and Battery Storage makes electric underfloor heating a much lower cost option and can influence the decision of electric or water based underfloor heating.

What is the impact on floor height elevation of electric versus water underfloor heating systems?

Underfloor Heating

Both water and electric systems can be installed into screeded floors during a build phase of a house or extension. An inscreed solution has no impact on floor height.

If the project is a renovation, installing both electric and water systems will raise the floor height, but the impact is very minimal.

Electric systems raise the floor height by 2-10mm depending on the thickness of the insulation board used (if any).

Water systems offer a low profile solution for retrofit projects, which increase the floor height by 15-18mm.





City Plumbing can help you get what you need to install an underfloor heating system

No matter what type of underfloor heating you are looking to install, here at City Plumbing we are happy to offer a wide range of high quality underfloor heating solutions at competitive trade prices with a market leading hassle free service.

  • Bespoke quotation within 24 hours
  • Free Next Day Delivery (to branch or site)
  • 6 Days per week Technical Support
  • Warranties & Guarantees

Contact your local branch today for further information.