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Heat pumps · UK

VaillantVWS 53/8.1 iQ

Vaillant VWS 53/8.1 iQ
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The Vaillant VWS 53/8.1 iQ is a heat pump with SCOP (35 °C) 5.71 and refrigerant R290.1

Last updated: Technical specifications Rules in the UK ⇄ Compare this model
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SCOP (35 °C)
5.711

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
5.04kW1
Official source
Rated output 55 °C
4.9kW1
Official source
UK

Rules in the UK

Boiler Upgrade Scheme

Check conditions

£7,500 – £9,0002Fixed 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.3,4

  • Must be MCS-certified (product and installer). Check the Ofgem product eligibility list.
  • Rated output 5.04 kW; the scheme covers systems up to 45 kW.
  • SCOP at 55 °C: 4.14. 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 source1
Performance
Rated output 35 °C 5.04 kW1
Rated output 55 °C 4.9 kW1
Efficiency
SCOP (35 °C) 5.711
SCOP (55 °C) 4.141
Seasonal efficiency ηs 35 °C 220 %1
Seasonal efficiency ηs 55 °C 158 %1
Energy label 35 °C A, , , 1
Energy label 55 °C A, , , 1
Noise
Indoor unit sound power 37 dB(A)1
Refrigerant
Refrigerant R2901
Refrigerant GWP 31
Refrigerant charge 0.65 kg1

Manufacturer documentation

External links to Vaillant'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 Vaillant VWS 53/8.1 iQ?

The SCOP (35 °C) of the Vaillant VWS 53/8.1 iQ is 5.71.1

Which refrigerant does the Vaillant VWS 53/8.1 iQ use?

The refrigerant of the Vaillant VWS 53/8.1 iQ is R290.1

How much Boiler Upgrade Scheme grant can you get for the Vaillant VWS 53/8.1 iQ?

£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

Sources

  1. Heat Pump Keymark certificates — EHPA / DIN CERTCO (Heat Pump KEYMARK) · accessed 29 Sept 2026
  2. Boiler Upgrade Scheme: what you can get — GOV.UK · accessed 27 Sept 2026
  3. Boiler Upgrade Scheme: guidance for installers (V5) — Ofgem · accessed 27 Sept 2026
  4. Boiler Upgrade Scheme product eligibility — Ofgem · accessed 27 Sept 2026