You have questions, we have answers...ClearMirror FAQ's

Frequently asked questions


What is a ClearMirror?

A ClearMirror defogger is an ultra-thin electric heating pad that is easy to install. The pad adheres to the back of a mirror to prevent condensation (fog) from forming allowing you to see clearly. ClearMirror is the permanent solution to foggy mirrors. The Shower and ShowerLite ClearMirrors come with a mirror and a transformer to keep you safe in the shower.

How long has ClearMirror been around?

We have been making and selling ClearMirrors since 1999. We are installed in thousands of hotel, residential, spa, motorhome and yacht bathrooms around the world.

How do mirror defoggers (like the Original ClearMirror) work?

How Electric Fog-Free Mirrors Work Just like that dripping wet glass of ice-cold lemonade on a one-hundred degree, ninety-percent humidity day a bathroom mirror is the same. To reverse that process, or rather, keep it from happening in the first place you need to make sure that a surface is the same (or higher) temperature as the dew point. Dew point as defined by Wikipedia: 'The dew point is the temperature to which air must be cooled to become saturated with water vapor. When further cooled, the airborne water vapor will condense to form liquid water (dew). When air cools to its dew point through contact with a surface that is colder than the air, water will condense on the surface. The measurement of the dew point is related to humidity. A higher dew point means there will be more moisture in the air.'* By definition, a mirror would have to be warmed to a temperature warmer than the dew point to promote evaporation vs. condensation (also Wikipedia): 'At temperatures below the dew point, the rate of condensation will be greater than that of evaporation, forming more liquid water. The condensed water is called dew when it forms on a solid surface, or frost if it freezes. The condensed water is called either fog or a cloud, depending on its altitude, when it forms in the air. If the temperature is below the dew point, the vapor is called supersaturated. This can happen if there are not enough particles in the air to act as condensation nuclei.'* Along comes a mirror heater, also commonly known as mirror defoggers. There are many brands to choose from and they are manufactured throughout the world, but they all operate and are installed in a similar practice. A mirror defogger will normally be very thin, less than 1/8" and be made by either wires or a printed circuit laminated between two non-conductive pieces of material like silicon rubber or polymer. Out of the end will be two leads, these leads are neither neutral nor positive (it doesn't matter which side of the power supply is connected to either lead). On one side of the mirror defogger is an adhesive coating like a PSA, covered with a contact sheet. You peel the sheet and press it firmly and evenly onto the back of the mirror. You then connect the leads to a new junction box (hidden behind the mirror) and push the mirror back into place. The mirror defogger is turned on and off with the bathroom light or the bathroom fan. When turned on, the mirror heater gently warms the mirror (usually to 100 degrees +/-). Relative humidity maximizes at 100%, and if the air temperature (not water temperature) is anything less than 100 degrees (temperature of the mirror) the RH will max out at that temperature. In other words, the air temperature will need to exceed the 100+ degrees of the mirror for the fog to form. Highly unlikely in a typical shower, no matter how many shower heads, or how hot the water is. Full Article

How much heat does a ClearMirror produce?

About 100 degrees (+/-) with variations based upon full watt supply, length of time, air temperature, and wall/wall cavity temperature. Read More


How do you install a ClearMirror?

The Original ClearMirror can be installed to the backs of most vanity mirrors. See Original ClearMirror installation instructions for details. Original ClearMirror specifications click here. The Shower ClearMirror comes with a mirror (ClearMirror defogger attached), and a low-voltage transformer and is installed flush with your shower tile surround. Shower ClearMirror installation instructions. Shower ClearMirror specifications click here. The ShowerLite ClearMirror is a Shower ClearMirror but with the addition of LED lights. The ShowerLite is also installed flush with the shower tile surround, and can be installed either horizontal or vertical. ShowerLite installation instructions. ShowerLite specifications click here.

Can I stack more than one ClearMirror alongside another?

Yes you can, but don't overlap them and make sure that the power supply is sufficient for the extra power draw. We can help if you have any concerns or questions.

ShowerLite ClearMirror - are there any controls we need to know about? What is needed for roughing in/electrical? Is it only the cable shown on the supplemental instructions? How is this installed? Do we need to install BEFORE tile or is it installed AFTER tile?

The ShowerLite ClearMirror uses barrel connectors for the LEDs and the heater. They are powered together by the same transformer. The Transformer is plugged into a switched outlet… and could be separate or tied into another switched light in the bathroom.

Electrical rough in depends on local codes. In most cases, the wires can be run through the wall, but you may need a junction box. We provide the extension, so you have approximately 28 ft. The transformer needs to be accessible and have some air flow. Do not store in the wall.

Mirror can be mounted before or after tile. We recommend the mirror be on site to get accurate measurements.

Additional Questions? Please Call or Email

How 'deep' are the Shower and ShowerLite ClearMirrors? Does their installation impact framing?

The Shower ClearMirror is made from high quality 1/4" glass with the heater being less than 1/16" thick, while the ShowerLite ClearMirror is the same glass with added depth of 1/4" for the LED lights. Total mirror thickness plus LED lights is 1/2". The leads for both units exit very near the center of the heater (and mirror). No, the framing should not be impacted. A typical installation includes the removal of the backer board immediately behind the areas of the LED lights in order for the mirror to sit flush (with the tile) in the opening. Call or email us, we look forward to helping you.

What do I use to adhere my Shower or ShowerLite ClearMirror to the shower backerboard?

We can also tell you what not to use! Never, never, ever (did we mention never?) use an aggressive adhesive such as silicone (silicon), or ammonium based cleaners. Neither of these should come in contact with the edges or backs of mirrors. From the Shower and ShowerLite Product Pages, download our: Read Before You Install Page . Always use Palmer or Gunther Mirror Mastic (or other professionally approved mirror mastics that are 100% safe for the backs and edges of mirrors). NOW JUST APPROVED: Kerdi-Fix by Schluter - ClearMirrors work well with Schulter shower system Kerdi-Board!! Some links to purchase mirror mastics: DK Hardware Palmer Mirro-Mastic CR Laurence Royal Adhesives

I don't see any ground wires from the ClearMirror? What should I do with the supply ground?

Since we aren't licensed electricians, about all we can tell you is that you do not need a ground wire connected to a ClearMirror. In fact, make sure that you do not connect a ground wire to a ClearMirror wire lead --- it may cause a short and potentially cause damage to the ClearMirror. Per electrical code, it is usually permissible to cap and leave a ground wire inside the electrical box.

Schluter - Kerdi Board: Can ClearMirrors be used with Kerdi shower systems and be installed with Kerdi Fix adhesive?

Yes. We have done testing with Kerdi Board wall systems and we have tested using Kerdi Fix to adhere/waterproof Shower and ShowerLite ClearMirrors to the walls. The systems including the adhesive work fine with our mirrors and will not damage the silvering. Kerdi - Fix by Schluter

Can Shower or ShowerLite ClearMirror be used with Kerdi shower systems by Schluter?

Yes. We have tested adhering ClearMirrors to Kerdi wall systems with Kerdi-Fix adhesive and they work great! Our standard Shower or ShowerLite ClearMirrors (either 12"x12" or 12"x24") fit perfectly in their standard 12" niches.


Are ClearMirrors safe?

Yes. All ClearMirror products are UL and C-UL approved and listed. The Shower ClearMirror and the ShowerLite are low-voltage and completely sealed to ensure safe operation. All electrical work must be completed to national and local electrical codes.


How do I take care of a ClearMirror?

Use normal glass and mirror cleaners on the surface of your ClearMirror. Do not use any substances which are combustible, toxic, wax or oil-based because these could emit harmful fumes or discolor the mirror surface when heated. Never allow ammonia-based products or silicone adhesives to contact the mirror backing. This will cause the silvering to turn black and will void your warranty.


How do I buy a ClearMirror?

You can purchase directly through us, on Amazon, and by searching the web for other online etailers. Most kitchen and bath showrooms have access to ClearMirror products including the 270+ Ferguson Bath Showrooms throughout the United States. If you are looking to purchase a larger quantity of ClearMirrors for a hotel, apartment, spa or residence please contact us directly at 651.251.9036 for special arrangements and pricing.

Can I buy a standard size defogger and install it on my own mirror in the shower?

You certainly can, we have 8"x10", 10"x10", 14"x14", 16"x16", 8"x22", 10"x22" and others which are usually in stock. Tell us what you are looking for and we will try to match you with the correct heater size and transformer! Email us today....

Do you ship anywhere in the world?

We will ship to most places, best first step would be to contact us either by phone or by email and tell us about your need. We are very accomadating folks! Orders to Canada can be placed directly online.


What are the different types of ClearMirrors?

ClearMirrors come in three versions: The Shower, ShowerLite (with LED lighting) and the Original ClearMirror for the back of your vanity mirror. We make three kinds of mirror defoggers, and each ClearMirror comes in multiple sizes: The Original ClearMirror is a heating pad that is applied to the back side of the vanity mirror. The Shower ClearMirror is a fully assembled mirror and heating pad which is installed flush with a tile or stone shower surround -- great for shaving in the shower. The Shower ClearMirror is also available as a pad only for custom projects. The ShowerLite ClearMirror is a lighted, heated fog-free mirror. Similar to the Shower ClearMirror it installs flush with the tile.

What are the different types of mirror defoggers and are all brands the same?

A mirror defogger is usually 'Tested By' or sometimes 'To' Underwriters Laboratories (UL) standards. This can be a big difference for your safety and overall peace of mind. Sometimes they are tested 'To' or 'By' other safety testing agencies both in the United States and overseas. As long as they are Tested By, Certified By, or Listed By you can have confidence that this electrical device being installed in your shower or over your vanity has met a rigorous safety testing plan as set by a certified testing engineer. All others, be highly suspect before you click 'Buy Now'! A mirror defogger can be round, square, rectangle, big or small. It can be low-voltage (12 or 24 volts), or line-voltage (120 or 220 volts). The number of watts will vary based upon the safety rating of the maximum 'watt density' as permitted by certified safety testing, the country, and the operational need of the individual heater and its application. Low-voltage versions, typically for a recreational vehicle or in wet environments like showers and spas should come with a Class-2 transformer sized for the correct volts and watts. Again for safety, the shower versions and the Class-2 transformer should be Listed or Certified (not just 'Tested To') together, along with the installation procedure. We hope this helps your understanding of the different types of mirror defoggers / mirror heaters. We've been at this since 1998 and have confidence in calling ourselves experts but please reach out to any of the top American Made manufacturers for additional information. They are all very smart, have great products and have only your comfort and safety in mind. Full Article


What kind of warranty do I get with ClearMirror?

ClearMirror products come with a 5-year warranty on materials. We do not warranty parts that we did not include with the original purchase, nor do we cover labor for replacement parts.


Can I customize a ClearMirror?

Absolutely! We do a lot of custom applications including larger, smaller, and round. Tell us, text us, or email us, but send over your custom design so we can put together the perfect application for you and your client.

Can I get a round shaped Shower or Original ClearMirror?

Absolutely. Reach out directly to us in an email and include the following information: 1. Diameter = 2. Behind a vanity mirror (Original ClearMirror) or a shower application (Shower ClearMirror)? 3. Mirror needed or not, and if yes, the size of mirror - Note: For a shower application we suggest providing at least a 1" area of the perimeter of the mirror back to be exposed, i.e. 24" diameter mirror = 22" Shower ClearMirror defogger. For behind a vanity mirror, this exposed area is not required. 4. Lead time = Please keep in mind that round shaped mirrors are not standard shapes that we stock. The lead time on any custom shape or size will typically be a minimum of 4-week. We will do our best to suggest sizes we've built before and potentially saving engineering on costs. But engineering and custom manufacturing costs could add $250 to $500 per design. Call us if you want to talk about the project, we are happy to work with you. 651.251.9036

What about low-iron glass for the shower mirrors?

Low-iron mirror is a generic term in which the iron is replaced in the formation of the glass. Low-iron glass presents less of a green tint. Most low-iron glass types have a green tint still, but less than regular float glass. The primary use for this glass type is in back-painted glass where the naked eye can see the color shift. In every other application, it is because the end user does not want a green edge. For a mirror, it does not really make sense to switch to low-iron because the quality difference is not that great. 99.99% of all mirrors worldwide are made with regular float glass (regular amount of iron). The cost for low-iron glass (mirror) can often times be prohibitive as an option. Availability is difficult at anything less than the wholesale level, and the cost at the retail level could easy be 3 to 4 (or even more) times more expensive than regular float glass.

Professional and Project Pricing

Could my business become a ClearMirror re-seller?

We would be interested in talking to you. On a side-note, we have specialized pricing programs for bath showroom installations --- as long as you share images with us, and on Houzz. Drop us an email, or call us at 877.242.5327 to discuss your business growth interests with ClearMirror.

Do you offer professional and volume purchase discounts?

We sure do. Call us directly for pricing at 651.251.9036​ and we will be happy to work with you on your next project.

Issues and Concerns

Neither of the lights on my ShowerLite ClearMirror turn on!

If both LEDs are not working, it is most likely that the wiring is not correct.

  • The positive wires for the LEDs and the Transformer must all be together in the same connector and then all the negative wires in the other connector.
  • See the image below. All positive wires have writing on them and are together in one connector.
  • It makes no difference for the heater which is why the heater works and the LEDs do not.
  • The mirror comes set up like this and each mirror is tested.
  • The transformer wires are disconnected during installation and if the positive and negative leads are switched when reconnecting, the LEDs will not work… but the heater will.

If you are still having issues, please reach out to us right away!