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.

What type of thin-set/self leveler should I use when installing SunTouch Systems?

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

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.

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

You can shape the mat (see above) and you can pull out the heating element from the mat and glue it to the floor to fill in small areas.

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

No. That will ruin the mat. Each cable is built with a specific ohm (resistance) value, so the length must remain as it came from the factory.

Then 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 to each other, 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. Return the mat for one that is perfect for your project.

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

Yes and Yes. 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).

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

No and Never. Never cut the heating elements. Always embed the mat and WarmWire heating elements in mortar in the floor and that includes the factory splice that joins the heating elements to the power leads. Never put heating elements or factory splices in the wall.

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

Power leads are secured to the floor and this includes the factory splice to the heating elements. 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 needed and then you can hot-glue the factory power lead splice in the groove.

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.

Why should I use both an ohm meter (multimeter) and a Loudmouth?

Because these work well together. The ohm meter tells you the resistance (ohms) is up to 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. So, our advice is to use both devices when you install your radiant floor.

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 multi meters will read your body as a circuit if you touch both test probe tips with your fingers.

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

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

So, 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 jobsite traffic. We suggest you use the plastic SunTouch CableTrowel when you apply mortar over SunTouch.

What's a CableTrowel?

The CableTrowel is a lightweight and durable notched blade that applies a 3/8" layer of combed mortar over your heating elements. Installers like the light weight and the fact that it cleans easily. Most important, it doesn't damage the heating elements like sharp metal trowels.

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

The National Electrical Code requires GFCI protection for an electric radiant floor. The SunTouch SunStat has a built-in GFCI so you don't need an additional one in your circuit box.

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 spacefor the sensor. Or, you can carefully remove the grout between two tiles. Then install the sensor wire and probe in the gap and re-grout the joint. Don't cut the heating elements with your chisel and don't 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 into 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 the floor sensor.

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

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

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), and this works well, especially over concrete.

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

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

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

Polymeric sand is a good option for your consideration. 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 looking at to verify their product can be used above an electric snowmelt system.

Please note: This FAQ document is designed to answer common questions. Refer to the product's installation manual or appropriate instructions and warnings regarding installation, use and maintenance.