Geothermal heat pump S1256

homesplitwith water heater

Product overview
NIBE S1256 is an inverter-controlled ground source heat pump with an integrated 180 L water heater and a climate-friendlier refrigerant. The unit adapts automatically to building heat demand to minimize energy use and is designed for low noise operation (Quiet Mark certified). Suitable for houses up to approx. 400 m² and available in three output ranges: 1.5–8 kW, 3–13 kW and 4–18 kW. Seasonal performance factor (SCOP) reaches up to 6.22, delivering efficient heating and high hot-water capacity.

Key features

• Seasonal performance factor (SCOP) up to 6.22 for efficient space heating.
• Integrated 180 L hot water tank for substantial domestic hot water supply.
• More climate-friendly refrigerant reducing greenhouse gas impact.
• Inverter-controlled operation for automatic modulation to match heat demand and lower electricity consumption.
• Designed for low sound levels; Quiet Mark certified.
• Integrated Wi‑Fi and compatibility with wireless accessories for remote monitoring and control.

Advantages / Comfort and control

• High adaptability: automatic modulation ensures efficient operation across varying load conditions.
• Performance focus: large integrated hot-water volume and high SCOP reduce operating costs.
• User convenience: touchscreen interface, wireless accessories and smart connectivity for simplified system control.

Accessories (selected, as presented on the product page)

• NIBE FLM S45: Exhaust air module with fan for combined mechanical exhaust air recycling with NIBE ground source heat pumps.
• NIBE RMU S40: Room unit with 2.8” touch display including temperature and humidity sensors for remote control and monitoring.
• NIBE HTS 40: Sensor accessory recording humidity and temperature.
• NIBE PCM S40: Ground source accessory enabling passive cooling from rock, groundwater or surface collectors; managed via the heat pump touch control.
• NIBE PCS 44: Passive cooling accessory for installations using passive cooling.
• NIBE SRV 10: Wireless radiator thermostat for local room control.
• NIBE ELK 42 / ELK 26 / ELK 15: Electric immersion heaters for backup heating (various kW ratings).
• NIBE EF 45: Extension frame for installation flexibility.
• NIBE TOC 30: Top cabinet to conceal ventilation ducting and services above indoor units (various heights).
• NIBE POOL 40: Accessory for pool heating integration with dedicated control and sensors.
• NIBE ACS 45: 4-pipe Passive/Active Cooling Accessory.
• NIBE RPP 10: Wireless repeater to extend signal between smart-home products.
• NIBE CDS 10: Wireless CO2, temperature and humidity sensor for indoor comfort monitoring via the myUplink app.
• NIBE KB 25: Filling connection with insulation for brine filling (for heat pumps up to 13 kW).
• NIBE AXC 40: Accessory card for connecting and controlling mixing valves, circulation pumps and groundwater pumps.
• NIBE ROT 10: Wireless room thermostat for remote control and monitoring.
• NIBE BAU 40: Wall console for secure wall mounting.
• NIBE HR 10 / HR 20: Auxiliary relay / room unit accessories for system control and interfaces.
• NIBE ECS 40 / ECS 41: Kits to add additional heating circuits for multiple climate zones.
• NIBE PV: Integrated photovoltaic solution packages compatible with the heat pump.
• NIBE EME 20: Communication module converting Modbus RTU to Modbus TCP/IP for third-party integration.

Characteristics / Technical specifications

• Model: S1256
• Suitable building size: Up to approx. 400 m²
• Available output sizes: 1.5–8 kW, 3–13 kW and 4–18 kW
• Seasonal performance factor (SCOP): Up to 6.22
• Integrated water heater volume: 180 L
• Height: 1800 mm
• Width: 600 mm
• Depth: 620 mm
• Net weight: 231 kg
• Product efficiency class room heating (35 °C): A+++
• Product efficiency class room heating (55 °C): A+++
• System efficiency class room heating (55 °C): A+++
• System efficiency class room heating (35 °C): A+++
• Efficiency class water heating: A+
• Declared tap profile: XL
• Refrigerant amount, CO2 equivalent: 0.54 ton
• Certifications: Quiet Mark certified (low sound levels)