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Heat Mat Mirror Demisters

Mirror demister pads for steam-free bathroom mirrors.

Mirror Demisters

A simple to install solution to ensure mirrors remain permanently steam-free. 

Mirror defoggers are a low cost luxurious edition to a new build bathroom or renovation project. They are ideal for hotel developments or projects with multiple bathrooms. Mirror demisters should be controlled by a switch, they can be wired through the lighting circuit to only heat when the bathroom is in use and clear all condensation from showers or baths.

  • Automatically ensures mirrors are clear of steam and can be used at all times
  • Makes life easier 
  • Uses up to 50% less power consumption than the leading alternative
  • Regularly used in hotels, new build and refurbishment projects
  • Ideal for bathrooms, ensuites, wet rooms and leisure facilities
  • 17 different standard 230V sizes held in stock, over 400 different options to ensure a perfect fit
  • 12V SELV, 24V and 110V options available
  • Transformers available for SELV versions
  • Bespoke sizes and Voltages are available on request
  • No thermostat required in standard installations
  • Mains Voltage operation, removes the need for transformers
  • Independently BEAB approved and made in the UK

The mirror defogger or demister must not be run continuously, it should either be on a timer or wired up through the lighting circuit so it only heats when the bathroom is in use. A 50cm by 50cm unit uses only 50 Watts of power per hour.

Mirror demisters in various sizes

Selecting the correct sized heater

Normally the Mirror Demister closest in size, but smaller than the mirror in question should be selected. The area covered will remain condensation free plus an additional margin around the edge of the mirror heater.

Combining multiple units

Multiple units can be combined to ensure complete coverage for the mirror in question. When units are combined there must be a 10mm gap between each heater, and they should be wired in parallel.


Although a Mirror Demister is usually installed covering the majority of the mirror, there is no requirement for this to be the case and some people prefer the look of a smaller panel in the centre of the mirror to be clear, surrounded by an area of condensation. To obtain this effect, select a mirror heater significantly smaller than your mirror.

Simple installation

Mirror Demisters have a self-adhesive backing enabling it to be easily attached to the reverse of a mirror. The mirror can then be affixed to the wall and the mirror heater can be covered with mirror adhesive, which must be solvent free. If being used with a safety-backed mirror the backing should be earthed, as should all metal parts surrounding the mirror.

Suitable for nearly all mirrors

Glass is a good conductor of heat and Mirror Heat is suitable for all recognised thicknesses of mirror. The thicker the mirror, the longer it will take for the heat to permeate. Care should be taken with mirrors which have cut outs as the mirror will be weakened in that area. The possibility of weakness will be reduced if the corners of any cut-outs have radii.

Hotel projects

Mirror Demisters are particularly suitable for use in hotel projects where it can be wired in through either the bathroom lighting system or the key-card operated circuit. Mirror Demisters are specified as standard in most new hotel complexes or refurbishments.

Bespoke mirror heaters

Bespoke units can be manufactured to order as required. Alternative requirements for panel sizes, lengths of coldtail or Voltages can be easily accommodated.

Approved and guaranteed

Heat Mat's Mirror Demister systems are BEAB approved, manufactured in the UK in a BEAB approved factory and supplied with a 10 Year Warranty.


Self-adhesive backing secures the mirror heater in place. For larger mirrors 150W/m mats and loose 3mm cable can be used for demisting if they are encased in a tile adhesive and used with a thermostat.

Technical Data

  • Heating Element: Carbon with copper connections
  • Supply Voltage: 230V +/- 10%
  • Power Output: 200W/m2
  • Alternative voltages: 12V & 24V units are available
  • Housing: IP44
  • Insulation: Double insulated
  • Dimensions: Varies between products
  • Coldtail lead: 1m 0.75mm2 double insulated cable


Mirror demisters can be wired through the lighting circuit, or to a separate switch if preferred. The circuit must be protected by a 5 Amp fuse or circuit breaker, and the wiring circuit must contain an all pole disconnection. Mirror heaters are not suitable for use with power supplies controlled via a dimmer switch.


Heat Mat Mirror demisters are BEAB Approved and supplied with a Lifetime warranty. We supply a range of standard sizes or can specify a bespoke solution depending on your requirements.  

Product codes and sizes for standard 230V units 

 Product Code Size   Wattage (W)Resistance (Ω)
7015L025 150 x 250mm  6 8747
7020L025 200 x 250mm  9 5977
7030L025 300 x 250mm  13 3842
7030L081 300 x 810mm  48 1153
7040L025 400 x 250mm  18 2831
7040L045 400 x 450mm  33 1544
7040L081 400 x 810mm  61 849
7040L101 400 x 1010mm  76 679
7050L053 500 x 530mm  50 1034
7050L077 500 x 770mm  73 708
7050L105 500 x 1050mm  100 517
7060L029 600 x 290mm  32 1590
7070L077 700 x 770mm  103 499
7070L089 700 x 890mm  120 863
7070L101 700 x 1010mm  136 379
7070L113 700 x 1130mm  152 339
7070L129 700 x 1290mm  174 296

We have over 400 different sizes of Mirror demister available including 150, 200, 300, 400 and 500mm options. Product data for these sizes can be downloaded below:

150mm Mirror demister technical information

200mm Mirror demister technical information

300mm Mirror demister technical information

400mm Mirror demister technical information

500mm Mirror demister technical information

600mm Mirror demister technical information

700mm Mirror demister technical information

Bespoke sizes are also available, please contact us.

  • Simple to install
  • Ensures mirrors remain condensation free
  • Ideal for hotel projects
  • Low power consumption
  • Various Voltages and sizes available
  • Mix and match to ensure the perfect fit
  • Bespoke sizes can be manufactured
  • Low Voltage models and transformers are available
  • Resistant to moisture, vibration and ageing
  • Supplied with a Lifetime Warranty