FAQ

RADIANT FLOOR HEATING 101

Do you have questions about radiant floor heating? We have answers. If you can not find what you are looking for, ask us!

What is radiant floor heating ?

Radiant floor heating consists of directly heating a mass rather than the ambient air. The feeling of comfort is far superior to conventional methods such as baseboards, wall heaters or the forced air system. With warm feet, the occupant is more comfortable while enjoying substantial energy savings.

On which surfaces is a floor heating system installed ?

Depending on the chosen product, FLEXTHERM systems are installed on most subfloors including: plywood, smooth concrete, concrete panels, ceramic, acoustic membrane, uncoupling membrane, crack bridging membrane, wire mesh under a scratch coat, mortar bed or even buried in a concrete slab. Just follow the recommendations in the installation guide provided by FLEXTHERM to get the best performance from your installation.

Which floor coverings are compatible with a floor heating cable ?

Depending on the product chosen, FLEXTHERM systems are compatible with a wide variety of floor coverings including: ceramic, natural stone, engineered wood, vinyl, floating floors, linoleum, parquet flooring and carpet.

For coverings other than ceramic or natural stone, it is important to always check with the manufacturer about the compatibility of their product with a floor heating system. Just follow the recommendations provided by FLEXTHERM to get the best performance from your installation. FLEXTHERM does not recommend the installation of heating cables under hardwood or cork.

Is it necessary to insulate the floor before installing the floor heating system ?

In the case of a smooth concrete installation and to maximize the benefits of radiant floor heating, the concrete slab must be insulated to prevent heat loss. There are a variety of products available on the market to create a thermal barrier. The suppliers of insulation products will be happy to give you advice.

How much does heating cost if using a floor heating system ?

The cost varies from one installation to another. It depends on several factors including: local electricity rate (KwH), heat loss and insulation of the room, the level of comfort desired by the occupant and the duration of the heating. A radiant floor heating system can provide energy savings of up to 28% compared to conventional approaches. 

Can a floor heating system act as the primary source of space heating ?

Radiant floor heating can act as the primary source of space heating. Several factors are involved including: the level of insulation of the subfloor, the size of the room, the exposure of the external walls, the windows, the desired level of comfort as well as the power emitted by the system.

FLEXTHERM floor heating systems are available in two common voltages : 120V or 240V

FLEXTHERM products can be installed on 120 VAC or 240 VAC circuits, also commonly known as 110 or 220. On special order, 208 VAC systems can be delivered for special projects. In all cases, it is mandatory to have a dedicated circuit for heating.

Who can install a heating cable system ?

FLEXTHERM floor heating systems come with detailed installation instructions. A skilled handyman can install the heating cable by following the installation guide. You must ensure that the installation is done in accordance with the appropriate Electrical Code in your area. The thermostat must be connected by a qualified person where required by law.

You can find Certified Flexpert here!

FLOOR HEATING SYSTEM

You have questions about electric floor heating systems? We have answers. If you can not find what you are looking for, ask us!

Can FLEXTHERM floor heating systems be installed outdoors ?

No, FLEXTHERM products are designed for indoor floor heating in both dry and wet environments.

Can a cable be cut, shorten or extended with another cable ?

Never! FLEXTHERM heating cables are manufactured to very high quality standards which are applied at the factory to maintain its integrity, its security and ensure a long service life. The cable is calibrated at the factory to meet the heating needs of a specific floor area surface. Cutting it will render it unusable and the warranty will be void. Splicing (joining two cables) should not be done under any circumstances.

How do the cables stay on the floor ?

Three options are possible:

  • The Green Cable Surface or Green Cable Surface XL can be installed using FLEXTHERM’s Universal Snap-in Gauges™. Their design facilitates the installation of cables and ensures uniform spacing according to your type of installation. This is the only cable attachment method that keeps the FLEXTHERM warranty in effect.
  • The Green Cable Surface or Green Cable Surface XL can also be installed using the FLEXSnap+ installation system which allows the cable to be installed while standing. This system offers many benefits, including the possibility of installing the floor heating system and ceramic tiles all in one day.
  • The Green Cable Surface XL is designed to be inserted into an uncoupling membrane.  In the case of the Surface Mats, the substrate is self-adhesive and adheres easily to the installation surface.
Can we staple the cable to the floor ?

Never! This will void the warranty. Always use the FLEXTHERM Universal Snap-In Gauges™, the FLEXSnap+ system or an uncoupling membrane.

How to repair a cable that has been severed or damaged during an installation ?

FLEXTHERM has repair kits available for order to repair the severed or damaged cable. If necessary, FLEXTHERM offers support for the repair; please contact our Customer Service team.

Can FLEXTHERM heated floor systems be installed in a 3-season sunroom or solarium ?

Yes, the systems are approved for installation in a sunroom or solarium. Depending on the insulation of your solarium, the loss of heat due to windows and location, an additional heating system may be advisable to ensure better comfort during peak periods in winter.

Can FLEXTHERM heated floor systems be installed in a bathroom ?

Yes, the systems are manufactured using very stringent quality procedures and they meet the CSA and UL standards for wet installation. Rigorous manufacturing methods give the FLEXTHERM cable a distinctive advantage unmatched by competition.

Can FLEXTHERM heated floor systems be installed in a shower ?

Yes, the systems are manufactured using very stringent quality procedures and they meet the CSA and UL standards for wet environment installation. Rigorous manufacturing methods give the FLEXTHERM cable a distinctive advantage unequaled by the competition. A separate cable from the one covering the floor of the bathroom is recommended in the shower.

How long before installing the tiles after the heating system has been installed ?

The time required before installing the tiles after the first coat will be dictated by the products used. In general, between 3 and 24 hours of drying are necessary. Check with the supplier or manufacturer of the products used.

How long before starting the floor heating system after the floor has been installed ?

The curing time (cure) varies from one product to another. Mortars and self-leveling underlayment’s take some time to fully cure. They can take up to 28 days to cure completely. Consult the supplier or manufacturer of the product for their recommendations. It is not possible to accelerate the curing by heating. The consequences could be detrimental to the final quality of the cured product.

How much does the heated floor per square foot cost ?

The cost per square foot is difficult to calculate because many factors influence the price. First of all, you will need a thermostat regardless of the area covered, whether it is a room of 20 sq. Ft. or 200 sq. Ft. You will have to absorb the cost of the thermostat.

Thereafter, will you be installing with the use of a membrane? What will be the spacing of the cable? The type of floor covering? What will the subfloor be? Which cable model/size? The larger the area, the lower the price per square foot.

For the purpose of giving you a realistic price contact our customer service or make an online quote.

Can floor heating cause a fire ?

No, the system is protected by a built-in GFCI (Ground-Fault Circuit Interrupter) at the thermostat which will shut off the power in the event of a fault. In addition, as the cable or mat is buried in the concrete / mortar there is no oxygen, so no risk.

Who can install a floor heating cable system ?

FLEXTHERM floor heating systems come with detailed installation instructions. A skilled handyman can install the heating cable by following the installation guide. You must ensure that the installation is done in accordance with the appropriate Electrical Code in your area. The thermostat must be connected by a qualified person where required by law.

You can find Certified Flexpert here!

THE THERMOSTATS

Do you have questions about our programmable or non-programmable thermostats? We have answers. If you can not find what you are looking for, ask us!

What is the FLEXTHERM Thermostat for ?

The FLEXTHERM thermostat is used to precisely regulate the temperature of the floor of the room where it is installed using a probe (sensor) in the floor. Also, thanks to the built-in Ground-Fault Circuit Interrupter (GFCI), it will protect the occupants of the room and the heating cable itself in the event of a system malfunction.

How to program my FLEXTHERM thermostat ?

Consult the programming guide provided with the thermostat, or contact our Customer Service team for assistance.

Can the thermostat control and regulate the floor temperature for a period of time ?

Yes, if you have purchased a programmable thermostat (FLP35), a WI-FI thermostat (FLP55) or a programmable Touch screen thermostat (FLP60), simply program it following the instructions supplied with the thermostat.

It is possible to program up to 4 or 6 periods per day for each day of the week.

Can a thermostat support more than one heating cable system ?

A thermostat can accommodate multiple sets of heating cables that do not exceed 15 amps of load current in total. Beyond this level, expansion units in combination with a thermostat will take over. Each room must have its own thermostat.

How can I remove the childlock on the FLP35 model thermostats ?

To remove the childlock (padlock), from the FLP35 please follow these steps:

1- Press “Check mark or OK” once to activate the screen backlight.

2- Press “Check mark or OK” again to access the menu.

3- Now that the word “mode” is flashing, press and hold down the up and down arrows at the same time and keep them held down for about 5 seconds until the padlock icon disappears from the screen.

The thermostat is now unlocked.

Is the Concerto Connect WI-FI thermostat (FLP55) compatible with home automation systems such as Amazon (Alexa), Nest, Google Home, etc. ?

No, the CONCERTO Connect thermostat (FLP55) is not compatible with any home automation system.

My thermostat has a red light on, what should I do ?

The red light is connected to the ground protection.

If you pressed on the thermostat TEST button, the red light will come on. The test is therefore conclusive. Press the RESET button to restart the thermostat.

If the red light is on and you have not pressed on the TEST button, you can press the RESET button to restart the thermostat. If ever the red light comes back, please contact our customer service.

What is the ‘TEST’ button on the side of the thermostat ?

The TEST button is used to check the GFCI.

The probe has been forgotten and therefore not installed during installation. How to fix the problem ?

In the case of a ceramic tile covering, it is possible to install one probe sensor between two ceramic tiles (in the grout line).

Otherwise, it is also possible to put the thermostat in the ‘ambiant’ mode. However, please note that this setting isn’t optimal for certain conditions.

Contact our Customer Service team for help.

Why are there 2 floor sensors ? One with the Thermostat and one with the cable or mat.

FLEXTHERM includes a floor sensor with the thermostat and also one with each box of cables or mats.  You can install both probes in the floor as per installation guidelines. Only one should be connected to the thermostat.  In the case where a sensor was not well positioned in the floor, it is easy to disconnect the sensor and reconnect the other to the thermostat. 

Where can I find the guides of discontinued FLEXTHERM thermostat models ?

Click on the link below to see the guides of discontinued FLEXTHERM thermostat models.

User guides of discontinued products

WARRANTY

You have questions about our best warranties on the market for electric heated floors and our thermostats? We have answers. If you can not find what you are looking for, ask us!

What guarantees are offered by FLEXTHERM ?

FLEXTHERM heating cables offer a limited warranty depending on the product and subject to installation in accordance with the installation guide provided with the purchase. In addition, we offer a lifetime warranty on certain products when installed by our FLEXperts certified installers

Green Cable Surface, Green Cable Surface XL, Green Cable Mat: 25 years or Lifetime Warranty offered by our FLEXperts

Green Cable Concrete, Concrete Mat Xpress: 20 years or Lifetime Warranty offered by our FLEXperts

FLEXTHERM uncoupling membrane: 25 years or Lifetime warranty offered by our FLEXperts

FLEXSnap+ : 5 years

Thermostats and expansion units: 3 years

INSTRUCTION MANUALS

Find here all the manuals and instruction guides for all our products. If you can not find what you are looking for, ask us!

Where can I get the programming and installation manuals for thermostats and expansion units ?

The thermostat programming and installation manuals are provided by FLEXTHERM at the time of purchase of the thermostat.

To download the installation guide in PDF format, go to the thermostats pages of our website here.

Where can I get the installation guide for floor heating systems ?

The installation guide is an integral part of the package provided by FLEXTHERM at the time of purchase of a radiant floor system.

To download the installation guide in PDF format, go to the pages of the various floor heating systems of our website here.

About

Since its foundation in 1991, FLEXTHERM has been able to maintain its enviable reputation as a floor heating industry leader due to the importance it gives to the quality of the products it manufacturers but also its focus on innovation and customer service. Learn more