ThermoSphere Ultimate Underfloor Electric Heating Cable — main packshot of the loose-wire heating cable on its reel.
A close-up of a person's hand fixing a yellow heating wire into a blue Thermsophere ultimate mat with a small black component near the top left, against a white background.
A close-up of a person's hand fixing the yellow Thermosphere ultimate heating cable into place on the ultimate matting
A close-up of a person's hand wearing a red work glove, pressing down on Thermosphere ultimate yellow heating cables to place it into the ultimate matting.
A close-up of a hand using a grout float to place Thermosphere Ultimate heating cable into place on the ultimate matting.
A close-up of a bright blue Thermosphere ultimate matting with a repeating circular pattern, overlaid with three vertical yellow heating cables.
Close-up of a blue Thermosphere ultimate mat with a raised grid pattern, partially covered by wet gray self levelling compound, with yellow heating cables visible along the bottom.
A close-up of a person's hand using a trowel to apply tile adhesive over a blue Thermosphere ultimate mat with yellow and black heating cables.
A blue and green striped L-shaped bath mat on a white tiled bathroom floor, positioned in front of a white freestanding bathtub and a gray floor drain, with a tile cutout showing the Thermosphere Ultimate underfloor heating in place.
ThermoSphere Ultimate Underfloor Electric Heating Cable — technical detail view showing the cable construction and connection.
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ThermoSphere Ultimate Underfloor Electric Heating Cable — main packshot of the loose-wire heating cable on its reel.A close-up of a person's hand fixing a yellow heating wire into a blue Thermsophere ultimate mat with a small black component near the top left, against a white background.A close-up of a person's hand fixing the yellow Thermosphere ultimate heating cable into place on the ultimate mattingA close-up of a person's hand wearing a red work glove, pressing down on Thermosphere ultimate yellow heating cables to place it into the ultimate matting.A close-up of a hand using a grout float to place Thermosphere Ultimate heating cable into place on the ultimate matting.A close-up of a bright blue Thermosphere ultimate matting with a repeating circular pattern, overlaid with three vertical yellow heating cables.Close-up of a blue Thermosphere ultimate mat with a raised grid pattern, partially covered by wet gray self levelling compound, with yellow heating cables visible along the bottom.A close-up of a person's hand using a trowel to apply tile adhesive over a blue Thermosphere ultimate mat with yellow and black heating cables.A blue and green striped L-shaped bath mat on a white tiled bathroom floor, positioned in front of a white freestanding bathtub and a gray floor drain, with a tile cutout showing the Thermosphere Ultimate underfloor heating in place.ThermoSphere Ultimate Underfloor Electric Heating Cable — technical detail view showing the cable construction and connection.

ThermoSphere Ultimate Low Wattage Decoupling Membrane Heating Cable

ThermoSphere
Size: 12lm - 1.2m² - 68W
Price:
£59.99

Description

The ThermoSphere Ultimate Low Wattage Decoupling Membrane Heating Cable is a reduced-output version (approximately 57W/m²) of the popular Ultimate cable, designed to install into ThermoSphere Decoupling Membrane where a gentler supplementary warmth is preferred over well-insulated or underfloor-heated properties.

Key Benefits

  • TwistedTwin cable construction with in-line joint technology — no bulky hot/cold joint to cut into the floor
  • Lower output than standard Ultimate cable, ideal for well-insulated new-build floors
  • Installs directly into ThermoSphere Decoupling Membrane dimples, no fixing tape needed
  • Available in 12 lengths from 12lm (1.2m²) up to 200lm (18.5m²)
  • IP68 rated, safe for use in bathrooms, showers and wetrooms
  • Requires a compatible thermostat for installation

Applications

Suited to bathrooms, kitchens and living spaces in well-insulated or new-build properties where a lower background heat output is sufficient, as a primary or supplementary heat source under ceramic, porcelain and natural stone tiles.

Performance & Features

The twin-conductor cable clips into the membrane's dimpled profile without cutting or taping, and the in-line joint sits within the cold tail rather than the floor, speeding up installation and removing a common failure point.

Compatibility

Designed for use with ThermoSphere Decoupling Membrane (HDM and HDM-SA ranges) and a compatible ThermoSphere thermostat, such as the T-MO.

Supplied by Millcot as part of our full ThermoSphere underfloor heating range.

Downloads

FAQs

What's the difference between this and the standard Ultimate cable?
This low wattage version outputs around 57W/m² compared to 130–195W/m² on the standard Ultimate cable, suiting well-insulated floors where less heat input is needed.

What membrane does it install into?
ThermoSphere Decoupling Membrane (HDM-001, HDM-005, HDM-015) or the Self-Adhesive Membrane (HDM-SA-001, HDM-SA-015).

Do I need a thermostat?
Yes, a compatible electric underfloor heating thermostat such as the ThermoSphere T-MO is required to control the cable.

Can it be a primary heat source?
It can be used as a primary or supplementary heat source, but its lower output is best suited to well-insulated rooms.

Is it suitable for wet areas?
Yes, the cable is IP68 rated and suitable for bathrooms, showers and wetrooms when installed correctly.