The RESOL controllers for standard solar thermal systems. The DeltaSol® BS series provides a clear operating concept. The intuitive commissioning menu leads you through the initial confi guration in only a few steps.

The system selected is shown on the display, the status of the individual components is indicated by means of fl ashing codes.The DeltaSol® BS series is available in 3 versions, depending on the demands. Details concerning the number of the relays as well as additional functions are shown in the technical data.

The RESOL controller for standard Solar Thermal Systems including BS/2, BS/4 and BS PLUS controllers with a heat dump function, drainback functionality including a booster function, and more.


    • Drainback option
    • Heat quantity measurement
    • Function control
    • Commissioning menu
    • Unit °C and °F selectable
    • HE pump control via adapter

DeltaSol® BS/2, DeltaSol® BS/4, DeltaSol® BS Plus

    • 1 basic system layout (DeltaSol® BS/2),  3 basic system layouts (DeltaSol® BS/4), 10 basic system layouts (DeltaSol®BS Plus) to choose from
  • Tube collector function, thermal disinfection function, time-controlled thermostat function

Technical Data:

Inputs: 4 Temperatursensoren Pt1000
1 semiconductor relay (DeltaSol® BS/2), 2 semiconductor relays (DeltaSol® BS/4, DeltaSol® BS PLUS )
Switching capacity: 1 (1) A 240 V~ (semiconductor relay) 
Total switching capacity: 
1 A 240 V~ (DeltaSol® BS/2)
2 A 240 V~ (DeltaSol® BS/4, DeltaSol® BS Plus)
Power supply: 100 ... 240 V~ (50 ... 60 Hz)
Supply connection: type Y attachment
0,45 W (DeltaSol® BS/2)
0,74 W (DeltaSol® BS/4)
0,38 W (DeltaSol® BS Plus)
Temperature controls class: I (DeltaSol® BS/4, DeltaSol® BS Plus)
Energy efficiency contribution: 1 % (DeltaSol® BS/4, DeltaSol® BS Plus)
Mode of operation: type 1.C.Y action
Rated impulse voltage: 2.5 kV
Data interface: RESOL VBus
® current supply: 35 mA
Functions: differential temperature controller with adjustable system functions: function control according to BAFA guidelines, operating hours counter, tube collector function (DeltaSol® BS/4, DeltaSol® BS Plus), heat quantity measurement and pump speed control
Housing: plastic, PC-ABS and PMMA
Installation: wall mounting, mounting into patch panels is possible
Indication/Display: System-Monitoring-Display for visualization of systems, 16-segment and 7-segment display, 8 symbols for indication of system status and operating control lamp
Operation: 3 push buttons at the front
Ingress protection: IP 20 / EN 60529
Protection class: II
Ambient temperature: 0 ... 40 °C / 32 ... 104 °F
Pollution degree: 2
Dimensions: 172 x 110 x 49 mm / 6.77" × 4.33" × 1.92"

default BS/4 - Technical Product Brief (1.18 MB) ;  BS/2-Technical Product BriefBS PLUS Technical Product Brief

default BS/4 - Installation & User Manual (2.96 MB) ; BS/2-Instlation & User Manual; BS PLUS - Installation & User Manual


Free Resol DeltaSol BS/2-V2

CTUVUS Certified

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Free Resol DeltaSol BS/4-V2

CTUVUS Certified

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Free Resol DeltaSol BS PLUS-V2

CTUVUS Certified

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