High-quality RTL valve for retrofitting radiant heating sets to both conventional heating systems and existing radiant heating systems
The Multibox 4K-RTL, which features an RTL valve, a thermostatic head for hydraulic balancing, a flow shut-off valve and a vent valve, ensures that the maximum system temperatures of retrofitted underfloor, wall and ceiling heating are not exceeded when connected to a heating system with high operating temperatures. Unlike the Kompabox, however, the Multibox can also be used to connect to existing low-temperature radiant heating systems.
Unlike conventional RTL boxes, our Multibox has a flow shut-off valve that allows water flow to individual heating surfaces to be interrupted manually. This is a significant advantage during maintenance or repairs, as it means that the heating system does not need to be completely drained. The flow shut-off valve also provides extra safety and control during commissioning.
The Multibox housing is designed to accommodate four-way manifolds for the supply and return flow. This protects the manifold fingers and prevents them from coming into contact with construction chemicals. It allows four heating circuits to be connected and controlled.
The V-exact II thermostatic valve enables hydraulic balancing, which can be used to adjust the flow of hot water through the heating surfaces, ensuring even heat distribution and energy-efficient operation of the radiant heating system.
The also included vent valve allows all gases, especially air, to be removed from the system without the need for additional tools. Regular venting ensures the heating system functions optimally and delivers full performance.
The Multibox's thermostat head can be replaced with a wireless thermostat that is compatible with smart home systems. This enables the Multibox to be integrated into standard smart home systems and controlled via them. The required connection thread is 30 × 1.5 mm.
The Multibox 4K-RTL serves as the perfect link between an existing heating system and a retrofitted underfloor heating system. It can regulate the temperature in retrofitted rooms completely independently of the existing heating system, offering the highest levels of workmanship, safety and ease of maintenance.
How the RTL valve works
The control system works via an integrated return temperature limiter valve (RTL), which limits the return temperature to a maximum of 50°C. The RTL valve thus protects the heating surface against excessive operating temperatures and prevents the installed materials from overheating.
The control system operates without additional auxiliary energy and can be individually adjusted using the thermostat head supplied. This functions as a continuous proportional controller. The change in room air temperature (controlled variable) is proportional to the change in valve stroke (control variable). If the room air temperature rises, the liquid in the temperature sensor expands and acts on the corrugated pipe. In this way, the water supply in the underfloor heating circuit is throttled or increased via the valve spindle.
Design and connection of the Multibox 4K-RTL
The Multibox comprises a flush-mounted box with a frame and mounting rail, offering sufficient space for the distributor fingers used to connect up to four heating circuits to the flow and return. The included cover plate and thermostat head ensure a high-quality appearance.
Existing heating pipes can be connected to the 3/4" threaded connection of the RTL Multibox using compression fittings. The distribution fingers of the FLEXIRO underfloor heating system can be connected without tools using plug connectors. The Multibox's installation dimensions are 190×240×60 mm (H×W×D). The Multibox is supplied with installation and operating instructions.
- Flow shut-off for easy maintenance
- Vent valve for optimum operation
- Thermostat head with V-exact II for performing a hydraulic balancing
- Flush-mounted box with frame, mounting rail and cover plate
- Installation dimensions in mm (H×W×D) 190×240×60
- Threaded connections (Eurokonus) 3/4"
- Smarthome integration possible
- Also suitable for retrofitting other radiant heating systems with larger pipe diameters
- Corresponds to IMI Heimeier Hydronic Engineering Multibox Eclipse K-RTL
- RTL Boxes - comparison of technical features
