⚠ This controller is out of stock until 8 October. Order now and we will ship as soon as it arrives. If you order other parts at the same time, we will send those straight away.
Identifying your controller
The RESOL DeltaSol® BS/4 was the differential temperature controller fitted to a range of Australian solar hot water systems in its 1–2 sensor configuration. If your controller is labelled DeltaSol® BS/4 and was set up with one roof sensor and one tank sensor, this is your original part.
The RESOL DeltaSol® BS/4 is no longer manufactured. The current direct replacement is the RESOL DeltaSol® SLL, described below.
The RESOL DeltaSol® SLL is the current replacement controller for the RESOL DeltaSol® BS/4, BS/2, BS Plus, AX and AL. It is the smallest controller in the SL series, optimised for small and medium-sized solar thermal systems, with 2 pre-configured basic systems available. It offers automatic function control to the VDI 2169 directive and a V40 flowmeter input for heat quantity measurement. The tube collector function makes it suitable for both flat plate and evacuated tube collectors.
The DeltaSol® SLL supplied in Australia is a market-specific version, confirmed by RESOL. It does not include a thermal disinfection function, an SD card slot, or VBus RPT remote parameterisation. If your existing controller uses any of these, please contact us before ordering.
RESOL DeltaSol® SLL — Specification
- Relay outputs: 2 semiconductor relays, 1 A each, 2 A total at 240 V
- Sensor inputs: 4, for Pt1000, Pt500 or KTY sensors
- Flow input: 1 x V40 impulse input for heat quantity measurement
- PWM outputs: 2, for high-efficiency pump speed control
- System layouts: 2 pre-configured
- Function control: automatic, to VDI 2169
- Tube collector function: yes — suits evacuated tube and flat plate
- Thermostat function: yes
- Data interface: VBus®
- Power supply: 100–240 V, 50–60 Hz
- Ingress protection: IP 20 — indoor, dry location only
- Ambient temperature: 0 to 40 °C
- Dimensions: 110 x 166 x 47 mm. Mounting centres 130 mm
What you receive: the RESOL DeltaSol® SLL 1-2 sensor controller, supplied with two new sensors — one 20m roof sensor and one tank sensor. New sensors are always supplied with a replacement controller and must be fitted at the same time. Reusing existing sensors with a new controller voids warranty.
