SolaX ALT06-SF0 vs STIEBEL ELTRON WPL-A 05.2 Plus HK 230
SCOP (35 °C): SolaX ALT06-SF0 4.66, STIEBEL ELTRON WPL-A 05.2 Plus HK 230 5.35. The STIEBEL ELTRON WPL-A 05.2 Plus HK 230 is better on 7 of 14 comparable points.
Who wins where
- SolaX ALT06-SF0
- STIEBEL ELTRON WPL-A 05.2 Plus HK 230
Biggest differences
| Fact | ALT06-SF0 | WPL-A 05.2 Plus HK 230 |
|---|---|---|
| Heating capacity (A7/W35) | 6.25 kW | 2.77 kW |
| Refrigerant charge | 0.74 kg | 1.4 kg |
| COP A-7/W35 | 2.93 | 3.47 |
| SCOP (35 °C) | 4.66 | 5.35 |
| Outdoor unit sound power | 48 dB(A) | 43 dB(A) |
| COP A7/W35 | 5 | 5.48 |
Score per area = position (0–100) relative to all 1350 models in this category; higher is better.
| Technical specifications | SolaXALT06-SF0 | STIEBEL ELTRONWPL-A 05.2 Plus HK 230 |
|---|---|---|
| Grants & market | ||
| Boiler Upgrade Scheme | £7,500 – £9,000 | £7,500 – £9,000 |
| General | ||
| Type (source) | Air-to-water 1 | Air-to-water 1 |
| Performance | ||
| Heating capacity (A7/W35) | 6.25 kW ✓ 2 | 2.77 kW 3 |
| Rated output 35 °C | 6 kW ✓ 1 | 5.92 kW 1 |
| Rated output 55 °C | 6 kW ✓ 1 | 5.86 kW 1 |
| Min. outdoor temperature | -22 °C 2 | -22 °C 3 |
| Efficiency | ||
| SCOP (35 °C) | 4.66 1 | 5.35 ✓ 1 |
| SCOP (55 °C) | 4 1 | 4.08 ✓ 1 |
| Seasonal efficiency ηs 35 °C | 201 % 1 | 211 % ✓ 1 |
| Seasonal efficiency ηs 55 °C | 157 % 1 | 160 % ✓ 1 |
| Energy label 35 °C | A, , , 2 | A, , , 3 |
| Energy label 55 °C | A, , , 2 | A, , , 3 |
| COP A7/W35 | 5 1 | 5.48 ✓ 1 |
| COP A2/W35 | – | 4.72 1 |
| COP A-7/W35 | 2.93 1 | 3.47 ✓ 1 |
| Noise | ||
| Outdoor unit sound power | 48 dB(A) 1 | 43 dB(A) ✓ 1 |
| Refrigerant | ||
| Refrigerant | R290 1 | R290 1 |
| Refrigerant GWP | 3 2 | 3 3 |
| Refrigerant charge | 0.74 kg ✓ 1 | 1.4 kg 1 |
| Electrical | ||
| Max. power input | 2.7 kW 1 | 3.24 kW 1 |
| Connectivity & smart | ||
| SG Ready | Yes 1 | Yes 1 |
Sources
- List of eligible heat pumps (BEG) — Bundesamt für Wirtschaft und Ausfuhrkontrolle (BAFA) · accessed 27 Sept 2026
- Heat Pump Keymark certificates — EHPA / DIN CERTCO (Heat Pump KEYMARK) · accessed 29 Sept 2026
- Heat Pump Keymark certificates — EHPA / DIN CERTCO (Heat Pump KEYMARK) · accessed 29 Sept 2026