Supplemental supply units with RAINMASTER D or floating switch
The supplemental supply unit is delivered complete with wall mounting clamp, funnel, discharge hose and assembly material, and comes in two different models:
System installation
The most common installation for a system with supplemental supply unit is illustrated in the figure below. In comparison to the RAINMASTER water suppy unit, it is important that the overflow is installed above the backwater level since there is a connection by the pipework between the cistern and basement. Otherwise there is a possibility that water from the sewer could enter the basement if there is a back-wash.

1. Supplemental supply unit | 7. MULTI-IS submersible pump |
2. RAINMASTER D | 8. PLURAFIT inlet calmer |
3. Mains water connection | 9. Rainwater inlet pipe |
4. Pressure line to fixtures | 10. Protective conduit for pressure line and sensor cable |
5. Level sensor | 11. MD100 wall bushing |
6. PURAIN rainwater filter |
Assembly, installation and maintenance
The INTEWA supplemental supply unit minimizes installation time. Improper installation of the “air gap“, as per DIN EN1717 is excluded. The supplemental supply unit is to be installed above the so-called backwater level. As a general rule, the backwater level is usually street level.
- The top edge of the funnel must be > 20 cm (3) above the backwater level.
- An additional adequate dimensioned emergency overflow must be provided.
- The supplemental supply (1) is to be piped frost-proof via a inlet calmer into the tank.
- A submersible pump supplies the water to the fixtures (2).