How to Install FLEXIRO DIY Low Profile Underfloor Heating
Step-by-step installation instructions
Our DIY low profile underfloor heating is a system kit that has been optimised for easily retrofitting existing heating systems in selected rooms such as bathrooms or kitchens. All required components are included in a single kit. The use of a flexible 10 mm PE-RT pipe ensures a low construction height and even heat distribution compared with conventional underfloor heating systems.
The installation of our wet underfloor heating kit is simplified by the use of plug-in connections and return temperature limiter for controlling the individual room temperature, so that FLEXIRO is equally suitable for professional installers and do-it-yourself enthusiasts. The following images illustrate the assembly steps in a test setup for the installation variant with nubbed mats.
Despite the simplified installation, we must point out here that we as the manufacturer can only guarantee perfect factory delivery, but not for the installation and connection by third parties. Please also pay attention to the currently valid standards and regulations for heating systems.
SCOPE OF SUPPLY FLEXIRO UNDERFLOOR HEATING KIT WITH NUBBED MATS
The detailed scope of the kit can be found in the PDF installation guide. You will also find further accessories and suitable tools in the FLEXIRO Shop.
NOTE:
As a general rule, the following also applies to FLEXIRO low profile underfloor heating: Work on heating systems requires sufficient technical knowledge and skills. If necessary, have the installation carried out by a specialist.
IMPORTANT INFORMATION BEFORE STARTING THE INSTALLATION
Determine the arrangement of the heating circuits. The installation position of the RTL-Box should be chosen so that the heating pipes from all heating circuits can be routed directly to the box without extending the heating pipes.
Note: Kit 2.5 m² = 1 heating circuit; 5.0 m² = 2 heating circuits; Kit 7.5 m² = 3 heating circuits and 10.0 m² = 4 heating circuits.
The pipes of the underfloor heating can be shortened. However, it must be ensured that the differences in length between the individual connections do not exceed 15%.
IMPORTANT INFORMATION BEFORE STARTING THE INSTALLATION
Avoid crossing pipes in order to take full advantage of the low construction height of thin underfloor heating.
Always make sure that the pipe is cut straight and burr-free. The pipe must not be squashed or kinked.
The installation of distributors and pipes does not require any special tools.
PREPARING THE INSTALLATION
The existing substrate must be level, clean, dry and load-bearing. Any primers can already be applied.
Before laying the pipes, determine the position of the connection manifolds for the underfloor heating so that you know exactly where you need to lead the pipes.
The arrangement of the heating system and the positioning of the RTL-Box can be designed individually. Please ensure that the control valve can be accessed later. It must be possible to insert the pipe ends into the individual connections after assembling the manifolds.
INSTALLING THE RTL-BOX
In order to provide efficient temperature control, the RTL-Box should be positioned in such a way that the thermostatic head can detect the temperature of the indoor air and the air can flow around it unhindered.
The installation and operating instructions enclosed with the UFH kit must be observed.
APPLYING EDGE INSULATION STRIPS
Gap-free edge insulation strips should be applied to all walls or vertical components (stairs, columns, door frames, ascending pipes). These must always reach the upper edge of the top covering.
The edge insulation strips are cut off once the top covering has been completely laid (or, in the case of tiles, once the tiles have been grouted).
LAYING NUBBED MATS
Before installation, the planned heating area should be marked out on the floor and, if necessary, the nubbed mats cut to size.
Note: The nubbed mats are asymmetrical! You therefore need to pay attention to the direction in which you lay them. The overlapping edges are free of any adhesive mesh or film. They are also not cut off smoothly, but are "wavy". These edges are darkly shaded in the sketches.
Tip: In case of doubt, you can first test out how you lay them before removing the protective film.
LAYING NUBBED MATS
To fix the nubbed mats, remove the protective film, position each mat with the adhesive side facing down and press downwards. Make sure that you observe the laying direction and arrange each nubbed mat correctly.
The second nubbed mat is laid so that its edge overlaps with the first.
The mats are joined by pressing the overlapping nubs into each other. The film from the second nubbed mat must also be removed and the mat firmly pressed downwards.
LAYING HEATING PIPES ON THE NUBBED MATS
The optimum starting point for laying the pipes is near the distributor arms in order to keep the pipe length for the connection as short as possible.
The minimum distance between the pipes is 10 cm. The distance between the underfloor heating and the room walls should be at least 5 cm. In areas where the pipes curve, a minimum bending radius of 10 cm must be ensured – we recommend keeping the radius as large as possible.
Cut out any kinks or damaged areas on the pipe.
LAYING HEATING PIPES ON THE NUBBED MATS
Please take care if you have to step on the nubbed mats when laying the pipe. The pipes should be laid without any twisting.
Snail/bifilar-shaped installation is particularly advantageous. In addition to the even distribution of heat, it has large radii, which makes it easier to avoid twisting the pipes. Before pouring, it must be ensured that the pipes are fastened everywhere and that the nubbed mats are firmly attached to the floor. Dowel hooks mounted to the floor can be used to help secure everything.
CONNECTING TO THE RTL-BOX
The distributor arms are connected to the RTL-Box by means of the Eurocone screw connection. The Eurocone has a self-sealing effect while the metal screw connection has a purely safety-related function. Over-tightening should be avoided as this would compromise the safety of the underfloor heating system.
CONNECTING TO THE RTL-BOX
This illustrations shows the arrangement of the heating pipes in the RTL-Box. The heating pipes are connected to the distributor arms using the simple plug-in assembly. The heating pipes that have just been cut and possibly shortened are inserted directly into the plug-in connections of the distributor arms up to the stop.
CONNECTING TO THE EXISTING HEATING SYSTEM
As a rule, you can either integrate your FLEXIRO underfloor heating into the existing heating system parallel to existing radiators or instead of a radiator.
Make sure that the supply and return lines are correctly connected in the RTL-Box. Mixing up the supply and return lines in the Box will disable the thermostatic valve and even prevent the flow through the FLEXIRO underfloor heating system.
APPLYING THE FLOOR SURFACE
The self-levelling compound used for radiant heating systems must generally be of a "flexible" nature to allow the floor to withstand the expansion stresses caused by heat. The underfloor heating must be turned off when applying the self-levelling compound.
The minimum construction height is 12 mm if a ceramic floor surface is chosen. With other floor surfaces, the self-levelling compound should provide an additional covering of at least 5 mm above the heating pipes. All floor coverings must be rated "suitable for underfloor heating" by the respective manufacturer.
COMMISSIONING (HEATING UP PROCESS)
After complete installation of the underfloor heating and once the surface covering has naturally dried, the heating up process takes place. If you have laid tiles, do not operate the underfloor heating until the tile adhesive has completely hardened. Please follow the manufacturer’s application instructions.
Heating-up is usually carried out according to a heating-up protocol. It is essential that you follow the manufacturer's instructions.
Installation Guide - DIY Underfloor Heating Kit with Nubbed PlatesComprehensive installation guidelines with all required information for retroffiting a low profile wet underfloor heating using nubbed plates.978 KB