Heat pumps · UK

NIBE S1157-5 EM 1X230V

The NIBE S1157-5 EM 1X230V is a heat pump with SCOP (35 °C) 4.88 and refrigerant R290.^1,2

Last updated: 18 October 2026Technical specifications Rules in the UK ⇄ Compare this model

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SCOP (35 °C): 4.88²
Seasonal efficiency: how much heat you get per kWh of electricity across a heating season.
Refrigerant: R290¹
Official source
Type (source): Ground source¹
Official source
Rated output 35 °C: 5kW²
Official source
Rated output 55 °C: 4kW²
Official source

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 5 kW; the scheme covers systems up to 45 kW.
SCOP at 55 °C: 3.83. 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 source¹
Performance
Rated output 35 °C	5 kW²
Rated output 55 °C	4 kW²
Efficiency
SCOP (35 °C)	4.88²
SCOP (55 °C)	3.83²
Seasonal efficiency ηs 35 °C	192 %²
Seasonal efficiency ηs 55 °C	150 %²
Energy label 35 °C	A+++²
Energy label 55 °C	A+++²
Noise
Indoor unit sound power	39 dB(A)²
Refrigerant
Refrigerant	R290¹
Refrigerant GWP	3¹
Refrigerant charge	0.15 kg¹

Variants

This model is registered in 14 combinations (for example with a different indoor unit or cylinder) with exactly the same performance. All figures on this page apply to each of these types. The part of the type number that differs is in bold; small differences (e.g. cylinder volume or anode) are listed after it:

S1157-5 EM 1X230V
S1157-5 EM 3X230V
S1157-5 EM 3X400V
S1157-5 PC EM 1X230V
S1157-5 PC EM 3X400V
S1257-5 E EM 3X400V
S1257-5 E PC EM 3X400V
S1257-5 R EM 1X230V
S1257-5 R EM 1X230V UK
S1257-5 R EM 3X230V
S1257-5 R EM 3X400V
S1257-5 R PC EM 1X230V
S1257-5 R PC EM 1X230V UK
S1257-5 R PC EM 3X400V

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Guides on heat pumps

How we collect and check this data →

Frequently asked questions

What is the SCOP (35 °C) of the NIBE S1157-5 EM 1X230V?

The SCOP (35 °C) of the NIBE S1157-5 EM 1X230V is 4.88.^1,2

Which refrigerant does the NIBE S1157-5 EM 1X230V use?

The refrigerant of the NIBE S1157-5 EM 1X230V is R290.^1,2

How much Boiler Upgrade Scheme grant can you get for the NIBE S1157-5 EM 1X230V?

£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

Heat Pump Keymark certificates — EHPA / DIN CERTCO (Heat Pump KEYMARK) · accessed 18 Oct 2026
European Product Registry for Energy Labelling (EPREL) – heat pumps — Europese Commissie · accessed 15 Oct 2026
Boiler Upgrade Scheme: what you can get — GOV.UK · accessed 27 Sept 2026
Boiler Upgrade Scheme: guidance for installers (V5) — Ofgem · accessed 27 Sept 2026
Boiler Upgrade Scheme product eligibility — Ofgem · accessed 27 Sept 2026

Key figures