When you need reliability, fit ThermoSphere Ultimate^® heating cable!

The only underfloor heating cable to combine TwistedTwin cable, and in-line joint technology in one award winning package (2023 Flooring Innovation Winner).

When installing electric underfloor heating, you hope never to go back. ThermoSphere Ultimate^® is quick and easy to install, plus it’s the most reliable underfloor heating cable on the market. That’s because ThermoSphere Ultimate combines a TwistedTwin cable, and in-line joint technology. This removes the risk of damaging the cable during installation, as cutting into the membrane and substrate is no longer required.

For total peace of mind With guaranteed reliability there's little to no chance of the cable failing when installed correctly. We’re so confident about this that should the underfloor heating system fail in the first twelve months of installation because of a manufacturing fault, we will not only replace the system, we'll also replace the floor covering too (available after confirmation of successful warranty registration). So, sit back and relax because we’ve got you covered.
	Speed up installation and reduce risk Unlike most electric heating cables, there's no bulky hot/cold joint that needs cutting into the floor. This transforms installation into a one-step process, making it faster and easier while significantly reducing any chance of accidently damaging the cold tail joint during installation. No cutting also means the membrane’s waterproofing layer stays intact.
Use it with any membrane mat ThermoSphere Ultimate is compatible with all decoupling membrane mats. This means you can use your preferred brand of decoupling mat with the easiest to install and most reliable heating cable.
	Take advantage of in-line joint and TwistedTwin technology ThermoSphere Ultimate is the ONLY heating cable to combine in-line joint technology with TwistedTwin cable construction. This makes it the most robust 'in-line joint' heating cable you can use – giving quick quality workmanship for your customers.

Features and Benefits of the ThermoSphere Underfloor Heating Cable

ThermoSphere Heating Cable Chart

Click the links below to see downloadable data sheets and instructions for this product:

• Click here to see the ThermoSphere Ultimate Underfloor Heating Loose Lay Cables data sheet
• Click here to see the ThermoSphere Underfloor Heating Loose Lay Cables installation instructions

What is ThermoSphere Ultimate

Our in-line joint membrane cables do not have bulky hot/cold joints that are created after the primary manufacturing process. They are the same thickness from the end termination to the cold tail that connects to the thermostat. This makes them stronger, more reliable, and easier to install.

Why is ThermoSphere Ultimate heating cable better?

Our in-line joint membrane cables make installation easier because installers don’t have to cut into the membrane, insulation board, or chase out concrete. Cutting and chasing also makes joints the most common point of failure during installation. Removing the bulky joint removes that risk too.

How easy is it to install ThermoSphere Ultimate?

Very. You can simply press the cable into the membrane mat, covering the whole of the heated area, and you’re done. Because there are no bulky joints or thicker cold tail cables, installation is a one-step process. The membrane and cable are automatically flush and ready for tiling.

What heating cable lengths are available?

There are four new cable lengths: 42m, 55m, 90m and 175m. But all the existing lengths will become in-line joint too, which means you’ll have a cable for every project.

The environment is critically important not just now, but for generations to come. That's why for every electric underfloor heating mat and thermostat combination that we sell, ThermoSphere plant a tree to help reforestation and secure a greener future.

They aim to reduce plastic waste at their headquarters by 50%, re-use or recycle 100% of their cardboard and improve energy efficiency with continued investment in cleaner technologies including LED lighting and electric vehicles.

They recognise and accept their responsibility to be a good steward of the environment and to help achieve a state of sustainable development. In support of these responsibilities, we have established the following commitments:

• Provide electrical heating systems and products that offer minimal environmental impact whenever possible
• Comply with all applicable environmental legislation with an aim of exceeding compliance wherever practical and possible
• Prevention of pollution in all its forms
• Conservation of natural resources, including energy, through resource reduction, reuse and recycling wherever practicable
• Conformance with Environment Agency licences
• Continual environmental performance improvement through the involvement of all employees and the local communities

Delivery Times

Delivery times for all delivery services are Monday to Friday (excluding Bank Holidays) 8am - 6pm. A 'working day' is Monday to Friday, excluding bank holidays. Weekends and bank holidays do not count as working days.

Delivery Costs

For information on delivery costs, please visit the main Delivery page.