PumpSwap

NIBE S2125 vs Ideal Logic Air: Which Air Source Heat Pump Is Better? (2026)

Quick Verdict

Ideal Logic Air is the more efficient choice on its MCS-certified figures, with lower estimated running costs.

Side-by-Side Comparison

FeatureNIBE S2125Ideal Logic Air
Installed price (before grant)Price on quotePrice on quote
After £7,500 grant (illustrative, England and Wales)Price on quotePrice on quote
SCOP at 35°C (MCS)4.85.09Higher
SCOP at 55°C (MCS)3.71Higher3.65
Largest size12kWLarger homes10kW
Standard warranty2 yearsNot published
Longest warranty (conditions apply)7 years7 years
Sound power (declared)49 dB(A)Lower55 dB(A)
Annual running cost (est., 45°C flow)~£620/yr~£605/yrLower
Refrigerant and max flowR290, up to 75°C flowR32, maximum flow temperature not published
CountrySwedenUK
UK brandNoYes
Best forBuyers who put quiet running and a long warranty first, and will use a NIBE Pro installerHouseholds who want a UK-built heat pump from a familiar boiler brand, installed through Ideal's installer network

Specifications and pricing are indicative for the UK market as at June 2026. Post-grant figures illustrate the £7,500 Boiler Upgrade Scheme in England and Wales (Scotland uses the Home Energy Scotland grant and loan; Northern Ireland has no equivalent). Running costs assume ~10,000 kWh of heat a year at 26.32p/kWh (Ofgem cap average, October to December 2026; changes quarterly). Confirm current models and exact pricing with your MCS-certified installer.

Price Comparison

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). Ideal Logic Air 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). So this pair cannot be ranked on price. In England and Wales the £7,500 Boiler Upgrade Scheme grant comes off either quote equally, with 0% VAT until 31 March 2027; your MCS-certified installer claims the grant for you. Compare written quotes on the same basis: unit size, cylinder, radiator changes and warranty.

Efficiency Comparison

SCOP (seasonal coefficient of performance) is the key efficiency measure for a heating heat pump: the kilowatt-hours of heat you get per kilowatt-hour of electricity across a whole heating season. The figures here are MCS-certified, at 35°C flow (underfloor heating or large radiators) and 55°C (hotter radiators). NIBE S2125 is certified at 4.8 at 35°C and 3.71 at 55°C, while Ideal Logic Air is certified at 5.09 and 3.65. On our estimates at a 45°C design flow temperature, the Ideal Logic Air costs about £15 a year less to run at Ofgem cap electricity prices, or approximately £150 over ten years. Real-world efficiency depends heavily on system design and flow temperature, which is what the MCS heat loss survey is for.

Warranty Comparison

NIBE S2125: 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. Ideal Logic Air: Up to 7 years parts and labour when registered within 30 days of installation and serviced annually (terms apply). The term without registration is not stated. Ideal also sells a paid ongoing heat pump plan from £22.50 a month. Workmanship cover for the installation itself comes separately from your installer and should be in writing.

Noise Comparison

Noise matters in UK homes because the outdoor unit often sits close to a neighbour's boundary or a bedroom window. The like-for-like figure is the maker's declared sound power: the noise the unit itself emits. NIBE S2125: 49 dB(A). Ideal Logic Air: 55 dB(A). On paper the NIBE S2125 is quieter by 6 dB(A). What a neighbour hears is much lower and falls with distance, and permitted development rules require the installation to meet the MCS noise standard at their window, so siting matters as much as the unit.

Cold-Weather and Retrofit Suitability

Two things decide how well a unit suits an older UK home: cold-weather output and flow temperature. NIBE S2125 uses R290 refrigerant (up to 75°C flow), while Ideal Logic Air uses R32 (maximum flow temperature not published). Modern units hold useful output well below freezing. In the colder parts of the UK (Scotland and northern England in particular), frosty mornings trigger short defrost cycles that trim efficiency, so ask each installer for low-temperature output figures and take the MCS heat loss survey seriously; radiator upsizing is more commonly recommended there so the system can run at efficient flow temperatures.

Pros and Cons

NIBE S2125

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

Ideal Logic Air

Pros

  • Built in Hull by a UK-headquartered heating manufacturer
  • Quiet Mark certified
  • Up to 7-year parts and labour warranty when registered within 30 days and serviced annually
  • Designed to pair with Ideal's pre-plumbed heat pump cylinders and Halo controls
  • 8 kW and 10 kW share one outdoor unit size: 1,008 x 1,095 x 518 mm, 110 kg

Cons

  • Uses R32 refrigerant rather than R290 (Ideal's R290 option is the separate HP290 range)
  • 55 dB(A) declared sound power, higher than the Panasonic, NIBE and LG models here (49 to 54 dB(A))
  • MCS directory SCOP for the 10 kW (4.57 at 35°C) is well below Ideal's published 5.19
  • Maximum flow temperature and standard warranty term are not published
  • No published installed price

Which Should You Choose?

Choose NIBE S2125 if...

  • A lower declared sound power matters to you (49 vs 55 dB(A))
  • You want natural R290 refrigerant

Choose Ideal Logic Air if...

  • You want the higher certified efficiency (SCOP 5.09 vs 4.8 at 35°C, MCS)
  • You want lower estimated annual running costs (~£605/yr vs ~£620/yr)
  • You want a UK brand with local manufacturing or headquarters behind it

The grant is the same, whichever brand you pick

Every air-to-water unit on this page qualifies for the £7,500 Boiler Upgrade Scheme grant in England and Wales (£9,000 for oil and LPG heated homes until March 2027) when fitted by an MCS-certified installer, who claims it on your behalf so it comes straight off the quote. Scotland uses the Home Energy Scotland grant of up to £7,500 (£9,000 rural and island) plus an optional interest-free loan; Northern Ireland currently has no equivalent scheme. 0% VAT on residential installations applies UK-wide until 31 March 2027. Accurate as at July 2026.

Boiler Upgrade Scheme guide →Gas boiler vs heat pump calculator →

Heat pump guides

Learn More

NIBE S2125 full reviewIdeal Logic Air full reviewCompare all brands
Free Quote
Step 1 of 4

Where are you?

See indicative costs and local installers for your area

100% freeNo obligationTakes 30 sec