S2125

NIBE S2125 is a current inverter-driven air-to-water outdoor-unit family using R290 refrigerant. The UK technical list includes 8, 12, 16 and 20 designations, with single-phase and three-phase versions available for some sizes. The complete code is therefore needed to establish both size and electrical arrangement.

Temperature and output

NIBE publishes a maximum supply temperature of 75°C and says that up to 65°C can be maintained at an outdoor temperature of -25°C. These are operating-envelope claims. They do not mean that every S2125 size can deliver its nominal output efficiently at those conditions.

Model selection should use the manufacturer’s capacity and input tables at the local design outdoor temperature and proposed heating flow temperature. A high maximum temperature can help with particular operating conditions, but lower system temperatures generally remain important to heat-pump efficiency.

System arrangement

S2125 is an outdoor unit, not a complete heating and hot-water system. NIBE identifies the VVM S320 indoor module or an SMO controller as S-Series control options. The system also needs appropriate hydraulic, electrical, expansion and safety equipment, plus a hot-water cylinder where required.

R290 is a flammable refrigerant. The sealed refrigerant circuit is in the outdoor unit, and installation has to follow NIBE’s siting, clearance and service instructions for the exact product. It should not be positioned solely by cabinet dimensions or planning appearance.

S-Series control and myUplink provide monitoring and adjustment. The installer still needs to commission weather compensation, hydraulic flow, hot-water settings and any supplementary heater.

Heating-system design

S2125 system selection uses the full product code, phase, design heat loss, design flow temperature and available output at that point. The controller or indoor module, cylinder, supplementary heat, electrical load and DNO route form the rest of the system design.

NIBE currently describes Quiet Mark certification for the 8 and 12 designations. It should not be presented as covering every family member without checking. Acoustic compliance still depends on the exact unit, mounting, site position and assessment method.

Defrost and condensate drainage also need a reliable route that will not create an ice or slip hazard. Warranty eligibility depends on registration, installer route, servicing and the complete NIBE UK terms.

Related entries

• NIBE
• NIBE F2050
• NIBE VVM S320
• Design flow temperature