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Heat pumps · UK

NIBES1155-25

NIBE S1155-25
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The NIBE S1155-25 is a heat pump with SCOP (35 °C) 7.32 and refrigerant R410A.1,2

Last updated: Technical specifications Rules in the UK ⇄ Compare this model
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SCOP (35 °C)
7.322

Seasonal efficiency: how much heat you get per kWh of electricity across a heating season.

Refrigerant
R410A2
Official source
Type (source)
Ground source2
Official source
Rated output 35 °C
34kW2
Official source
Rated output 55 °C
31kW2
Official source
UK

Rules in the UK

Boiler Upgrade Scheme

Check conditions

£7,500 – £9,0003Fixed grant (England & Wales)

Fixed grant in England and Wales, deducted from your installer’s quote. £9,000 when replacing oil or LPG off the gas grid (until March 2027). Scotland: Home Energy Scotland grant instead.4,5

  • Must be MCS-certified (product and installer). Check the Ofgem product eligibility list.
  • Rated output 34 kW; the scheme covers systems up to 45 kW.
  • SCOP at 55 °C: 5.14. The installed system needs a SCOP of at least 2.8 (MCS calculation).
Heat pump grants in the UK explained →

Technical specifications

General
Type (source) Ground source2
Performance
Rated output 35 °C 34 kW2
Rated output 55 °C 31 kW2
Efficiency
SCOP (35 °C) 7.322
SCOP (55 °C) 5.142
Seasonal efficiency ηs 35 °C 285 %2
Seasonal efficiency ηs 55 °C 197 %2
Energy label 35 °C A, , , 2
Energy label 55 °C A, , , 2
Noise
Indoor unit sound power 47 dB(A)2
Refrigerant
Refrigerant R410A2
Refrigerant GWP 2,0882
Refrigerant charge 2.1 kg2
Grants & market
ISDE grant (NL) 6,675 €1

Manufacturer documentation

External links to NIBE's official website. The manufacturer may change or move documents; where they differ, the manufacturer's latest version applies.

Frequently asked questions

What is the SCOP (35 °C) of the NIBE S1155-25?

The SCOP (35 °C) of the NIBE S1155-25 is 7.32.1,2

Which refrigerant does the NIBE S1155-25 use?

The refrigerant of the NIBE S1155-25 is R410A.1,2

How much Boiler Upgrade Scheme grant can you get for the NIBE S1155-25?

£7,500 in England and Wales, provided the product and installer are MCS-certified (£9,000 when replacing oil or LPG off the gas grid, until March 2027). The installer applies and deducts the grant from your quote.1,2

Sources

  1. ISDE heat pump notification code list — Rijksdienst voor Ondernemend Nederland (RVO) · accessed 27 Sept 2026
  2. Heat Pump Keymark certificates — EHPA / DIN CERTCO (Heat Pump KEYMARK) · accessed 29 Sept 2026
  3. Boiler Upgrade Scheme: what you can get — GOV.UK · accessed 27 Sept 2026
  4. Boiler Upgrade Scheme: guidance for installers (V5) — Ofgem · accessed 27 Sept 2026
  5. Boiler Upgrade Scheme product eligibility — Ofgem · accessed 27 Sept 2026