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Heat pumps · UK

1 SINQ1SINQ ONE-21

The 1 SINQ 1SINQ ONE-21 is an air-to-water heat pump with a SCOP of 4.95 (35 °C) and a sound power level of 53 dB(A). Under permitted development the limit is 37 dB(A) measured 1 m in front of the centre of a neighbour’s habitable-room door or window. Free-standing, the indicative minimum distance is 2.5 m; against a wall 3.6 m.1

Last updated: Technical specifications Rules in the UK
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SCOP (35 °C)
4.951

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

Outdoor unit sound power
53dB(A)1
Official source
Refrigerant
R2901
Official source
Rated output 35 °C
21kW1
Official source
Rated output 55 °C
22kW1
Official source
UK

Rules in the UK

Minimum distance to your neighbour

MCS 020(a) (England, permitted development since 29 May 2025)2 · 1 m in front of the centre of a neighbour’s habitable-room door or window

Permitted development (MCS 020(a)) ≤ 37 dB(A) · LAeq,5min
Free-standing 2.5 m
Against wall 3.6 m
In corner 5 m

Indicative calculation (hemispherical, no barriers). Not a substitute for an MCS 020 assessment.

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 21 kW; the scheme covers systems up to 45 kW.
  • SCOP at 55 °C: 3.62. The installed system needs a SCOP of at least 2.8 (MCS calculation).
Heat pump grants in the UK explained →

Technical specifications

General
Type Air-to-water1
Compressors 11
Capacity control drehzahlregelung1
Performance
Rated output 35 °C 21 kW1
Rated output 55 °C 22 kW1
Efficiency
SCOP (35 °C) 4.951
SCOP (55 °C) 3.621
Seasonal efficiency ηs 35 °C 195 %1
Seasonal efficiency ηs 55 °C 142 %1
COP A7/W35 5.151
COP A2/W35 4.61
COP A-7/W35 2.741
Noise
Outdoor unit sound power 53 dB(A)1
Indoor unit sound power 36 dB(A)1
Refrigerant
Refrigerant R2901
Refrigerant charge 2.6 kg1
Electrical
Max. power input 14 kW1
Connectivity & smart
SG Ready Yes1

Frequently asked questions

Can I install the 1 SINQ 1SINQ ONE-21 without planning permission?

Under MCS 020(a) (England, permitted development since 29 May 2025) the unit must not exceed 37 dB(A) 1 m in front of the centre of a neighbour’s habitable-room door or window. With a sound power of 53 dB(A) that indicatively means 2.5 m free-standing, 3.6 m against a wall or 5.0 m in a corner. Your MCS installer must confirm this.1

How much Boiler Upgrade Scheme grant can you get for the 1 SINQ 1SINQ ONE-21?

£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

Which refrigerant does the 1 SINQ 1SINQ ONE-21 use?

The 1 SINQ 1SINQ ONE-21 uses R290.1

Sources

  1. List of eligible heat pumps (BEG) — Bundesamt für Wirtschaft und Ausfuhrkontrolle (BAFA) · accessed 27 Sept 2026
  2. MCS 020(a) (England, permitted development since 29 May 2025)
  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