NIBE S2125 Air Source Heat Pump
NIBE is a Swedish heat pump maker whose UK company, NIBE Energy Systems, is based in Chesterfield. The S2125 is its R290 monobloc air source heat pump, sold in the UK in 8, 12, 16 and 20 sizes, with the 8 and 12 Quiet Mark certified. NIBE says it has over 40,000 heat pumps installed in the UK and also sells installations directly through its NIBE Home service.
NIBE S2125 air source heat pump price UK (2026)
The Boiler Upgrade Scheme takes £7,500 off in England and Wales (£9,000 for off-gas homes replacing oil or LPG heating, until 31 March 2027); your MCS-certified installer claims it for you. Scotland uses the Home Energy Scotland grant and loan instead; Northern Ireland has no equivalent. 0% VAT until 31 March 2027 is already reflected. NIBE S2125 does not publish an installed price and no credible third-party figure exists, so we show none. For scale, the median Boiler Upgrade Scheme install cost £12,908 before the grant (DESNZ Boiler Upgrade Scheme median, April to June 2026). Running cost estimated at ~10,000 kWh of heat a year and 26.32p/kWh electricity (October to December 2026 cap). Accurate as at October 2026.
Warranty: 2 years parts and labour as standard; 5 years through a NIBE Pro installer; 7 years through a NIBE Pro Partner or Pro Exclusive installer. All terms need registration within 28 days, commissioning by a NIBE-trained installer, servicing every year and completed Benchmark paperwork; mainland Great Britain only; units within 1 km of the coast need a Blygold coating.SCOP is the MCS-certified seasonal efficiency; sound power is the maker's declared ErP figure, the like-for-like noise measure (what you hear next door depends on distance and siting). Prices are indicative; confirm with your MCS-certified installer.
Available Models
NIBE S2125-8
NIBE S2125-12
Specifications from the makers' datasheets and the MCS product directory, checked October 2026; prices are indicative. Running costs: Estimate for 10,000 kWh of heat a year at 26.32p per kWh (Ofgem price cap, October to December 2026), at a 45°C design flow temperature: the midpoint of the certified 35°C and 55°C SCOPs. Post-grant figures illustrate the £7,500 Boiler Upgrade Scheme in England and Wales. Confirm current models and exact pricing with your MCS-certified installer.
Pros
- R290 refrigerant
- Quiet Mark certified (S2125-8 and S2125-12) with 49 dB(A) declared sound power
- Up to 75°C flow, and up to 65°C at -25°C outdoor
- Up to 7-year parts and labour warranty through NIBE Pro Partner installers
- British Gas became an approved NIBE service partner in March 2025
Cons
- Standard warranty is 2 years unless a NIBE Pro installer registers the extended cover
- Heavy and deep: 163 kg and 831 mm deep for both the 8 and 12
- Size labels overstate output: the S2125-12 is rated 6.8 kW at 35°C, 8.34 kW maximum at -7°C
- Annual servicing is a condition of every NIBE warranty
- No published installed price
Best for
Buyers who put quiet running and a long warranty first, and will use a NIBE Pro installer
NIBE S2125 pricing and grants in your region
The hardware is the same everywhere; the support is not. England and Wales use the £7,500 Boiler Upgrade Scheme, Scotland the Home Energy Scotland grant and loan, and Northern Ireland currently has no grant. Each regional guide covers exactly what applies.
NIBE S2125 air source heat pump FAQ
How much is a NIBE S2125 air source heat pump installed in the UK (2026)?
NIBE S2125 does not publish an installed price and no credible third-party figure exists, so we show none. For scale, the median Boiler Upgrade Scheme install cost £12,908 before the grant (DESNZ Boiler Upgrade Scheme median, April to June 2026). In England and Wales the £7,500 Boiler Upgrade Scheme grant comes off whatever your installer quotes (£9,000 for off-gas homes replacing oil or LPG, until 31 March 2027), and 0% VAT applies. Ask for two or three written quotes on the same basis: unit size, cylinder, radiator changes and warranty.
Is a NIBE S2125 heat pump eligible for the £7,500 grant?
Yes. Every air-to-water unit on this page qualifies for the Boiler Upgrade Scheme in England and Wales when it is fitted by an MCS-certified installer, who applies for the grant on your behalf so it comes straight off the quote. Off-gas homes replacing oil or LPG heating can claim £9,000 instead, until 31 March 2027. Scotland uses the Home Energy Scotland grant and loan instead; Northern Ireland currently has no equivalent scheme. Grant details accurate as at October 2026.
Is NIBE S2125 a good air source heat pump brand?
NIBE is a Swedish heat pump maker whose UK company, NIBE Energy Systems, is based in Chesterfield. The S2125 is its R290 monobloc air source heat pump, sold in the UK in 8, 12, 16 and 20 sizes, with the 8 and 12 Quiet Mark certified. NIBE says it has over 40,000 heat pumps installed in the UK and also sells installations directly through its NIBE Home service. NIBE S2125 is best suited to buyers who put quiet running and a long warranty first, and will use a nibe pro installer.
What is the warranty on a NIBE S2125 heat pump?
2 years parts and labour as standard; 5 years through a NIBE Pro installer; 7 years through a NIBE Pro Partner or Pro Exclusive installer. All terms need registration within 28 days, commissioning by a NIBE-trained installer, servicing every year and completed Benchmark paperwork; mainland Great Britain only; units within 1 km of the coast need a Blygold coating. Workmanship cover for the installation itself comes separately from your installer. Most extended terms depend on registering the product and annual servicing, so keep your installation paperwork and MCS certificate.
How efficient is a NIBE S2125 air source heat pump?
The NIBE S2125-8 has an MCS-certified SCOP (seasonal coefficient of performance) of 4.8 at 35°C flow and 3.59 at 55°C, so over a heating season each 1 kWh of electricity delivers about 3.59 to 4.8 kWh of heat, depending on how hot your system runs. At a 45°C design flow and the Ofgem cap rate (26.32p/kWh), 10,000 kWh of heat costs an estimated £625 a year, against roughly £890 for a 90%-efficient gas boiler at the current cap gas rate (7.97p/kWh from 1 October 2026). Estimates, not quotes; heat pump time-of-use tariffs can do better.
How long does a NIBE S2125 heat pump last?
With an annual service, heat pumps are generally expected to run well beyond their warranty period (NIBE S2125: 2 years, up to 7 with conditions). Longevity depends on correct sizing (the MCS heat-loss survey), sensible siting and regular servicing. Confirm design life and extended-warranty options for your specific model with your MCS-certified installer.
NIBE S2125 vs other brands: which should I pick?
NIBE S2125 publishes no installed price, so we do not place it on price. Its S2125 is Quiet Mark certified with a declared sound power of 49 dB(A), reaches 75°C flow, and NIBE says it has over 40,000 heat pumps installed in the UK. See the side-by-side comparisons below for direct head-to-head specs.
NIBE S2125 vs other heat pump brands
Heat pump guides
- Air source heat pump installation cost in the UK
- The best air source heat pumps in the UK, compared
- The £7,500 Boiler Upgrade Scheme, explained
- Air source heat pumps: costs, grants and brands
- Heat pump grants in London
- Heat pump grants in South East England
- Heat pump grants in South West England
- Heat pump grants in East of England
- Heat pump grants in East Midlands
- Heat pump grants in West Midlands
- Heat pump grants in Yorkshire and the Humber
- Heat pump grants in North West England
- Heat pump grants in North East England
- Heat pump grants in Scotland
- Heat pump grants in Wales
- Heat pump grants in Northern Ireland
Other heat pump brands
Where are you?
See indicative costs and local installers for your area