How We Ranked the Brands
We evaluated brands on five criteria:
- Seasonal efficiency (SCOP)
- Build quality and reliability based on engineer feedback
- Parts availability
- Installer network size
- Value for money
Here are our top picks for 2025.
1. Mitsubishi Electric Ecodan — Best Overall
Consistent high efficiency, excellent reliability, superb parts availability. The first choice for most UK properties. SCOP up to 4.2.
2. Daikin Altherma — Best Efficiency
Class-leading SCOP ratings (up to 5.08 A+++), excellent build quality, good installer network. The Altherma 3 HT’s high-temperature capability makes it ideal for retrofit projects.
3. Vaillant aroTHERM Plus — Best Integration
Outstanding integration with existing Vaillant systems, R290 propane refrigerant for low environmental impact, SCOP up to 4.7. Excellent choice for Vaillant boiler replacements.
4. Samsung EHS — Best Value
Samsung’s EHS (Eco Heating System) offers strong performance at competitive pricing. Good engineer familiarity and solid reliability record in the UK market.
5. Nibe S-Series — Most Premium
Swedish-engineered quality, excellent longevity record, advanced controls. Higher upfront cost but exceptional long-term value for performance-focused buyers.
6. LG Therma V — Best for Apartments
Compact outdoor unit options and flexible installation make the Therma V ideal for properties with space constraints.
7. Panasonic Aquarea — Good All-Rounder
Solid efficiency, good range of sizes, and an improving UK installer network. Strong choice at mid-market pricing.
8. Worcester Bosch Greenstar — Best Brand Network
Widest UK installer network and strong after-sales support. Efficiency slightly behind the top tier but extremely well-supported.
Sources: MCS installation data and MCS certification.
