FAQs

About Floor Warming

1. What makes the floor warm?
2. Where do most people put their SunTouch floors?
3. Does a SunTouch mat weaken or strengthen my floor?
4. Is SunTouch electric floor warming efficient?
5. My bathroom is heated; do I need floor warming?
6. Is there any advantage to a "low voltage" electric radiant heating system?
7. What voltage do I need for my SunTouch floor?
8. Does 120 VAC work better than 240 VAC?
9. What's the warranty on SunTouch products?

1. What makes the floor warm?

The blue heating elements in both the orange weave of a SunTouch mat and WarmWire® cable get warm and transfer heat to the floor. The floor, in turn, transfers heat to the rest of the room. SunTouch UnderFloor™ does this with a warm blue aluminum surface suspended between floor joists.

2. Where do most people put their SunTouch floors?

Bathrooms are the most common place, followed by kitchens and entryways. Mudrooms are also a great place for a warm floor. WarmWire works great in larger areas, like basements or great rooms.

3. Does a SunTouch mat weaken or strengthen my floor?

SunTouch mats have been tested by the Tile Council of North America (TCNA) to ASTM C 627, officially known as "A Standard Test Method for Evaluating Ceramic Floor Tile Installation Systems Using the Robinson-Type Floor Tester." It tests for deflection under increasing weight loads on a wooden framed floor or with a concrete slab floor. SunTouch mats passed these tests for HEAVY classifications, such as shopping malls and commercial areas. SunTouch mats apparently add tensile strength to the tile and mortar sandwich. When in doubt, follow TCNA and ANSI (American National Standards Institute) specifications.

4. Is SunTouch electric floor warming efficient?

Radiant floors warm people and objects directly without overheating the air. Electric radiant converts nearly all its energy into a usable form. You can set the home thermostat lower and still be comfortable. Use a programmable SunStat thermostat and the system automatically sets to a lower temperature when the rooms are not in use. Insulate below the floor or below the heating system and on top of the concrete slab to allow the system to respond faster and use less energy.

5. My bathroom is heated; do I need floor warming?

Even when bathrooms are heated with forced air or baseboard, their tile floors are cold. Imagine starting the day by stepping out of the shower onto a warm, comfortable tile floor!

6. Is there any advantage to a "low voltage" electric radiant heating system?

No. SunTouch and competitors deliver about the same amount of energy to the floor. They may use less voltage, but require higher amperage to be able to generate the same wattage (heat delivery). SunTouch, however, uses line voltage, and lower amperage to deliver the necessary wattage. This allows a larger SunTouch system to be installed with a smaller breaker. Low-voltage systems use transformers that are noisy, hot, and hard to hide, both visually and acoustically. All North American bathrooms have access to 120 volt (VAC) power and by code, must install SunTouch systems with GFCI protection. A GFCI detects ground faults and will disconnect the energy to the heating system within milliseconds if necessary.

7. What voltage do I need for my SunTouch floor?

SunTouch is built for 120 VAC or 240 VAC (for warming larger areas).

8. Does 120 VAC work better than 240 VAC?

Both systems have the same efficiency. The best option is to see what power is available for your installation. 240 VAC is more common outside the United States and in commercial applications. A SunStat thermostat can control up to 150 square feet of heated floor on 120 VAC or 300 square feet on 240 VAC.

9. What's the warranty on SunTouch products?

SunTouch heating elements are covered by a limited twenty-five (25-year) product replacement warranty. SunTouch will carry a one- to three-year limited warranty based on the SunStat model purchased. The SunTouch warranty is transferable to a new homeowner, unlike those from most other radiant heating companies. SunTouch warranties apply to the product, not just the original homeowner.

 

Planning Your Floor

1. You make different products, so which one is the best one for my application?
2. Specifically, how is WarmWire different from SunTouch mats?
3. What's the minimum/maximum wire spacing for WarmWire?
4. How much SunTouch mat or WarmWire do I need?
5. Will the SunTouch system raise my floor height? If so, by how much?
6. How much more thinset will I need for a SunTouch floor?
7. What kind of floor coverings can I put over my new radiant floor?
8. Are there floor coverings that don't work well over a radiant floor?
9. Do I need to put insulation under my SunTouch floor?
10. I am installing SunTouch on a concrete slab. Should I add an insulation barrier?
11. Can I install SunTouch floor heating in a shower floor?
12. Do you recommend a control to manage my radiant floor?
13. How much load can a SunStat handle?
14. Where's a good place to locate a control?
15. Can I buy directly from the manufacturer?

1. You make different products, so which one is the best one for my application?

SunTouch mats work great in thinset or self-leveling mortar over frame floors or slabs. Normally rooms needing less than 150 square feet of heated area with square corners are the best for SunTouch mats. They are usually covered with tile and used in bathrooms and kitchens. Coated WarmWire does the same thing, but it costs less, installs with straps and can be used in showers. (Note: older, uncoated versions of WarmWire are not rated for shower use.) Rooms needing more than 150 square feet of heated area and/or rooms with angles or arcs are good for WarmWire, which easily molds itself to unusual shapes. If your floor is cold and you have access from below through a crawl-space or unfinished basement, you can install SunTouch UnderFloor mats between your floor joists to warm the tile, stone or wood floors above.

2. Specifically, how is WarmWire different from SunTouch mats?

Custom TapeMat® is the fast-lane option for electric floor heating. A mat is ordered to fit an exact desired floor plan. Custom TapeMats are made to fit curves, angles, and cut-outs as required by the room design.

Standard TapeMats install faster in rectangular spaces. Everything is preset for you. Mats add a fiber reinforcement to the thinset mortar, which makes the floor stronger. The heating elements are factory-woven into a coated polyester mat with optimal 3-inch spacing and 12-watts-per-square-foot output.

WarmWire costs less per square foot than heating mats, and the installation works well with unusual room shapes. For that reason, WarmWire is more popular in larger areas or rooms with angles, curves, nooks, or tight spaces that don't fit well with mats. You can adjust the spacing of WarmWire to match the heat loss from the room.

3. What's the minimum/maximum wire spacing for WarmWire?

The WarmWire strap can hold down heating elements at 2.5-inch, 3-inch or 3.5-inch spacing. 2.5-inch spacing is suggested for rooms with high heat loss and concrete slabs. Use insulation below the floor if possible. 3-inch spacing is the most common spacing for baths, kitchens, living rooms, and basements with moderate heat loss. 3.5-inch spacing is best for rooms with low heat loss or hallways or large areas that are heated with heat ducts. Never use spacing of less than 2.5 inches or or more than 3.5 inches for WarmWire.

4. How much SunTouch mat or WarmWire do I need?

Use the new SunTouch Product Calculator (WarmWire Calculator / TapeMat Calculator). For many projects, one mat is sufficient, but a project can use multiple mats wired in parallel to warm larger areas with a limit of 15 amps of load on a single control.

This is the basic calculation:

1. Calculate total wall-to-wall area of the rooms. Subtract square footage of all built-ins (such as tub, toilet, and cabinets).

(Total area – built-ins) = (___ - ___ ) = ___ sq. ft.

2. Multiply by 0.90. Round down to the nearest 5 sq. ft. This is the heated area.

_____ x .090 = _____ sq. ft. of heated area

3. Based on square footage of heated area, select the appropriate mat(s) or WarmWire from the product catalog.

5. Will the SunTouch system raise my floor height? If so, by how much?

Expect 1/8 to 3/8 inch of increased floor height, depending on the installation method. Here are three examples:

Most installers use a ¼- to 3/8-inch notched trowel to apply thinset mortar. If thinsetting and setting tile directly over the heating elements, figure on 1/8 to 1/4 inch of increased height.

If you skim coat thinset over the heating system first, let it dry, and then thinset the tile. Figure on ¼ to 3/8 inch of added thickness.

Or, you can apply ¼ to 3/8 inch self-leveling thinset to cover the heating elements and then cover with a finished floor covering material such as a laminate.

If you install SunTouch UnderFloor between floor joists, the finished floor height will not change.

6. How much more thinset will I need for a SunTouch floor?

A safe estimate is to plan on using 60% more thinset than would normally be needed with a cold floor.

7. What kind of floor coverings can I put over my new radiant floor?

If you embed the heating elements in mortar, or if you install SunTouch Underfloor, you can use many kinds of floor coverings. The most popular warm floors are tile and stone. If you cover the heating elements with a self-leveling thinset, you can install laminate, floating, or glue-down hardwood flooring.

8. Are there floor coverings that don't work well over a radiant floor?

Nail-down floors won't work for obvious reasons. Vinyl flooring may deform and discolor on top of the heating elements. A pad and carpet will insulate your radiant floor so you might be disappointed with its performance. Rubber and cork floors also have higher insulating values, so you may not be pleased with the warmth. Check with the manufacturer of a bamboo (a type of grass) floor to make sure it is rated for elevated temperatures. Although the temperature at the surface of a radiant floor should not exceed 85°F, the temperature at the bottom of the finished flooring could experience temperatures of 90 to 110°F.

9. Do I need to put insulation under my SunTouch floor?

Insulation will reduce heat loss and improve your response time during warm-up periods. If you can put it under the floor framing or under your thinset (following Tile Council of North America guidelines), insulation is a good idea. There are a number of products made to work under thinset floors. Check your local flooring distributor or dealer. In the case of SunTouch UnderFloor, insulation below the mat, between the joists, is essential.

10. I am installing SunTouch on a concrete slab. Should I add an insulation barrier?

Insulation dramatically enhances the performance and efficiency of floor warming systems.

11. Can I install SunTouch floor heating in a shower floor?

Yes. Both SunTouch mats and WarmWire are UL listed for installation in a custom shower floor or bench application. Refer to the SunTouch TapeMat installation manual or Custom TapeMat installation manual or WarmWire installation manual for further instructions.

12. Do you recommend a control to manage my radiant floor?

Yes. A SunTouch SunStat control has GFCI protection and a floor sensor to set the floor temperature. It has a system on/off switch that comes in handy and some models have programmable features to turn the system up and down, automatically, based on the entered schedule.

13. How much load can a SunStat handle?

SunTouch SunStats are dual-voltage thermostats (120 VAC and 240 VAC) rated for up to 15-amp service. They can handle up to 150 square feet of heated area at 120 VAC (15 amps) or 300 square feet at 240 VAC (15 amps). For larger areas that need one control, simply add a SunStat Relay for another 15 amps of heated area.

14. Where's a good place to locate a control?

Put the control above (or near) the spot where your power leads leave the floor. Place it in a UL-listed, extra-deep switch box between 54 and 60 inches from the floor or at a height mandated by your local building code. Choose a wall that is not in direct sunlight or an exterior wall.

15. Can I buy directly from the manufacturer?

No, and that's not because we don't appreciate your business. Local distributors and dealers offer real value in your local area. Their experience, common sense, inventory choices, and accessory products will make your project go much easier.

Installing Your Floor

1. Can I install SunTouch directly on plywood?
2. What type of thinset/leveler should I use when installing SunTouch systems?
3. Can I cut the mat to make it fit my area?
4. I have an unusual space in my bathroom. How can a mat cover that area?
5. Can I cut the heating element if I have too much?
6. What can I do if I have too much heating element on the job?
7. Can I shorten the shielded power lead? Can I shorten the sensor wire?
8. If I have heating elements left over, can I cut them or leave them in the wall?
9. The power lead is a little thicker than the mat. How do I install that?
10. What is a LoudMouth™ and do I need one?
11. Why should I use both an ohm meter (multimeter) and a LoudMouth?
12. I'm checking my resistance levels with a digital ohm meter (multimeter) and I am getting "OL" (open line) or I (infinite value), or no value between my power lead ground wire and each of the other wires. Is this normal?
13. If I cut or damage the heating element, can it be repaired?
14. How do I avoid damaging the heating elements?
15. What is CableTrowel?
16. Do I need a GFCI in my circuit box to supply power for the SunTouch system?
17. I forgot to install the sensor. What can I do?
18. I've got my SunTouch mat, but can't find the control sensor.
19. How do I secure WarmWire strap to a slab?
20. How do I insulate an existing slab before I install SunTouch?
21. Can polymeric sand be used to fill the joints between pavers installed above a SunTouch ProMelt™ system?

1. Can I install SunTouch directly on plywood?

Yes, SunTouch can be installed directly on plywood if it is covered with at least 3/8 inch of mortar. It is a good idea to coat the plywood with a primer that is compatible with your brand of polymer modified mortar. If you are installing a thinset tile floor over plywood, consider first putting down a layer of cement backerboard. Then, secure SunTouch to the backerboard and cover it with a latex or polymer modified mortar and then a finished tile or stone floor. In all cases, install the tile floors according to the Tile Council of North America guidelines.

2. What type of thinset/leveler should I use when installing SunTouch systems?

Use a latex or polymer modified thinset mortar and apply it with a 3/8-inch notched trowel. You may also cover the heating elements with a self-leveling compound that you mix on the job site. Stay away from pre-mixed mortars, adhesives, and quick-set self-leveling compounds.

3. Can I cut the mat to make it fit my area?

Yes. Roll out the mat until you come to an obstruction. Cut the orange weave and flip the mat to cover the next part of the floor. Repeat until you have covered the area you want to warm. Never install the mat on top of itself and never cut the blue heating element for any reason.

4. I have an unusual space in my bathroom. How can a mat cover that area?

You can shape the mat, pull out the heating element, and glue it to the floor to fill in small areas.

5. Can I cut the heating element if I have too much?

No, that will ruin the mat. Each cable is built with a specific resistance (ohm) value, so the length must not be changed.

6. What can I do if I have too much heating element on the job?

If you find you have too much heating element, you can always use of some of the excess next to the toilet or other areas you planned to leave unheated. You can run the loose heating elements as close as 2.5 inches apart, but stay away from the toilet ring. If your mat is too large for the project, don't roll it up in the wall; that will cause dangerous overheating. In that case, return the mat for one that is perfect for your project.

7. Can I shorten the shielded power lead? Can I shorten the sensor wire?

Yes to both questions. After you have pulled the shielded power lead and the white sensor wire into the control box in your wall, you will probably have some left over. You can cut off the excess and make the connections to the SunStat. Never cut the heating element wires or the sensor probe (the bulb at the end of the wire).

8. If I have heating elements left over, can I cut them or leave them in the wall?

No, do not cut them and never leave them in the wall. Never cut the heating elements. Always embed the mat and WarmWire heating elements, including the factory splice that joins the heating elements to the power leads, in mortar in the floor. Never put heating elements or factory splices in the wall.

9. The power lead is a little thicker than the mat. How do I install that?

Power leads, including the factory splice to the heating elements, are secured to the floor. Only the shielded power leads go into the wall and up to the junction box. You can use a router or chisel to make a groove in the floor for the power leads and factory splice if necessary and then hot-glue the factory power lead splice in the groove.

10. What is a LoudMouth™ and do I need one?

The LoudMouth monitors your heating elements during the installation. If they are damaged, a light comes on and an alarm sounds so you can stop work and take steps to fix the problem. A LoudMouth can monitor three sets of heating elements at a time and it should stay on as long as the heating elements are exposed on the job site. A LoudMouth is worth the money.

11. Why should I use both an ohm meter (multimeter) and a LoudMouth?

They work well together. The ohm meter tells you the resistance (ohms) meets factory specifications and the LoudMouth sounds an alarm if you damage the wire during installation. The ohm meter will also show a change in resistance if a wire is severed, but it doesn't sound an alarm. Our advice is to use both devices when you install your radiant floor.

12. I'm checking my resistance levels with a digital ohm meter (multimeter) and I am getting "OL" (open line) or I (infinite value), or no value between my power lead ground wire and each of the other wires. Is this normal?

Yes. If any resistance is measured between the green tagged wire (ground) and load wires, this would indicate a short circuit, meaning damage to the heating elements. Be aware that auto-ranging multimeters will read your body as a circuit if you touch both test probe tips with your fingers.

13. If I cut or damage the heating element, can it be repaired?

Never cut the blue heating element for any reason. If you damage it during installation, you can call our toll free number at 1-888-432-8932 and purchase a Heating Wire Repair Kit. The kit should be installed by a licensed electrician.

14. How do I avoid damaging the heating elements?

Use special care when you trowel mortar over SunTouch. Cover the SunTouch with cardboard when it is exposed, to minimize damage from job site traffic. We suggest you use the plastic SunTouch CableTrowel™ when you apply mortar.

15. What is CableTrowel?

The CableTrowel is a lightweight, durable, notched blade that applies a 3/8-inch layer of combed mortar over your heating elements. Installers like the weight and the fact that it cleans easily. Most important, it does not damage the heating elements like sharp metal trowels can.

16. Do I need a GFCI in my circuit box to supply power for the SunTouch system?

A GFCI should not be used because our thermostats come with built-in GFCI. This very sensitive GFCI can detect another GFCI on the circuit, causing what we call a nuisance trip.

17. I forgot to install the sensor. What can I do?

You can shatter and carefully remove one tile directly below the SunStat control location and then carefully chisel out a space for the sensor. Or, you can carefully remove the grout between two tiles, and then install the sensor wire and probe in the gap and re-grout the joint. Do not cut the heating elements with your chisel and do not install the probe right on top of the heating elements. Try to locate the probe between them.

Or, you may be able to carefully drill a small pocket in the bottom of a wood subfloor below the heated area and seal the sensor probe into this pocket.

You may also be able to switch to the built-in air temperature sensor in the SunStat by changing the options to "Air Sensing" mode or the timed "Regulator" mode. This works, but it is less accurate than using the floor sensor. Please note that the sensor will still need to be connected to the back of the SunStat control to allow the air mode to function properly.

18. I've got my SunTouch mat, but can't find the control sensor.

Your sensor is located in the packaging of the SunStat thermostat. It's a loose coiled, white wire.

19. How do I secure WarmWire strap to a slab?

Drilling holes and fastening the strap with screws is an approved method. If you have backerboard over plywood, you can use nails or screws to hold the strap. The fastest and easiest way, however, is to spray the back of the strap with high-strength spray adhesive. Hot glue is a good alternative to spray adhesive. We also include double-sided tape in our kits (or you can purchase it separately). That works well, especially over concrete.

20. How do I insulate an existing slab before I install SunTouch?

Some types of anti-fracture or crack-isolation membranes have minimal insulating properties. Secure them to the slab and then put WarmWire or SunTouch mat on top. At least 1/4 inch of insulating material will help reduce the heat losses into the slab below. Thicker insulation material tends to have a better R-value. Check with your local flooring dealers for products that are appropriate for radiant floors.

21. Can polymeric sand be used to fill the joints between pavers installed above a SunTouch ProMelt™ system?

Polymeric sand is a good option to consider. Some polymeric sand manufacturers have said the added heat will not harm their product. However, it is always a good idea to check with the manufacturer of the polymeric sand you are considering to verify that their product can be used above an electric snowmelt system.

Operating Your Floor

1. Your manual says I'm supposed to wait 30 days after installation to turn my SunTouch system on. Why?
2. How much will my radiant floor cost to operate?
3. At what temperature should I set my radiant floor?
4. What keeps my floor from overheating?
5. Does it take long for the floor to get warm?
6. What does a programmable control do?
7. What could go wrong with SunTouch products?
8. What kind of support do you provide?
9. How do I explain my SunTouch floor to my neighbor?

1. Your manual says I'm supposed to wait 30 days after installation to turn my SunTouch system on. Why?

Mortar requires 28 days to cure completely. If you turn on the heating elements before it is cured, it will shrink, crack, and pop up your tiles. Refer to the instructions on the bag of masonry or call the manufacturer.

2. How much will my radiant floor cost to operate?

Your cost will depend on how many hours you warm your floor and your cost of electricity. The SunTouch Product Calculator (WarmWire Calculator / TapeMat Calculator) will give you an estimate based on an average usage.

3. At what temperature should I set my radiant floor?

Use your control to find a temperature that feels good to you. Start at 80°F and then adjust to your comfort level.

4. What keeps my floor from overheating?

SunTouch controls have floor sensors and high-temperature limits to keep the floor from getting too warm. Most users would not want to exceed a surface temperature of 85°F. Many wood and laminate floor manufacturers want a limit of 82-84°F. Consult the wood or laminate manufacturer's materials for recommended maximum floor temperature.

5. Does it take long for the floor to get warm?

From a cold start, the system takes a while because it has to warm up the entire mass of the floor. Our digital controls help by "setting back" the temperature to a lower level, but not completely off. When the room is ready for the "comfort" temperature, the control will warm the floor up quickly. On average, this takes 20 to 45 minutes. Insulation below the floor warming system will reduce your warm-up time.

6. What does a programmable control do?

The SunStat programmable control lets you set a 7-day schedule for your warm floor. Typically, the floor gets warm in the morning and in the evening when you are using the room. Programmable controls are popular because they start warming before you come into the room and they reduce the floor temperature as you leave. In that way, you are always comfortable, but you don't waste energy.

7. What could go wrong with SunTouch products?

The installation manuals list several things that could cause damage to the product prior to installation. Typically, SunTouch is in greatest danger on the job site, where sharp tools and construction traffic can damage a heating element. Once the floor covering is installed on top of a SunTouch mat, there is very little that can harm it.

8. What kind of support do you provide?

Call our toll free number from the U.S. and Canada at 1-888-432-8932 from 7 AM to 6 PM Central Time, Monday through Friday. Our engineers and customer service people are here to answer your questions. Watch the installation videos available online and read the installation manual, which has a troubleshooting chart, if you have any questions.

9. How do I explain my SunTouch floor to my neighbor?

From Alaska to Florida, people spend a lot of time in bathrooms on cold tile floors. SunTouch provides a simple, low-cost way to start your day with warm feet.

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