Both Viessmann and Vaillant boilers are German powerhouses that offer premium gas heating solutions, but Viessmann focuses on innovative efficiency while Vaillant emphasises smart integration for homeowners and landlords seeking reliability or advanced features.
If you’re deciding between these for your property—perhaps to upgrade for better performance or sustainability—this head-to-head review covers their origins, awards, ratings, warranties, and models to help you choose in a market driven by energy savings and eco-standards.
Viessmann Boilers vs Vaillant Boilers: At a Glance
Viessmann and Vaillant both deliver high-efficiency gas boilers with strong German engineering, but Viessmann edges on innovation and low emissions while Vaillant stands out for smart tech and user-friendliness. To provide a quick snapshot before diving deeper, here’s a comparison table highlighting key differences.
| Feature | Viessmann | Vaillant |
| Origin | Germany (Allendorf, founded 1917, family-owned) | Germany (Remscheid, founded 1874, family-owned) |
| Efficiency Rating | Up to 98% (A-rated) | Up to 94% (A-rated) |
| Which? Score | 80% satisfaction (lower than 82% average) | 80-85% reliability, four-star customer score |
| Trustpilot Rating | 4.4/5 (over 5,484 reviews) | 4.6/5 (over 22,575 reviews) |
| Warranty | Up to 10 years with approved installer | Up to 10 years with approved installer |
| Price Range (Unit Only) | £900-£1,800 | £800-£1,500 |
| Popular For | Low NOx emissions, hydrogen-ready tech | Smart controls, quiet operation |
Why Consider Vaillant Boilers?
Consider a Vaillant boiler if you want a premium German brand with innovative smart features and strong eco-performance for future-ready heating.
Founded in 1874 in Remscheid, Germany, as a family-owned firm, Vaillant pioneered the wall-hung boiler in 1905 and has led in condensing tech since the 1990s, expanding in the UK with a focus on sustainable, efficient gas boilers that blend precision engineering with user-friendly designs for modern homes.
Vaillant Boilers: Awards
Vaillant boilers have won awards like the Housebuilder Product Award for ecoTEC exclusive in 2018 and Green Home Awards 2021 for aroTHERM plus heat pump, recognising innovation and sustainability. They’ve also earned the German Sustainability Award in 2023 for energy-efficient products, highlighting their commitment to low-carbon heating solutions.
Vaillant Boiler Warranty
Vaillant offers up to 10 years warranty on boiler parts and labour for models like ecoTEC when installed by an approved engineer, providing comprehensive coverage. This term reflects their quality, with heat exchanger extensions up to 10 years for added reassurance in UK installations.
Vaillant Popular Boiler Models
Vaillant popular boiler models emphasise smart integration and efficiency, with the ecoTEC line leading for versatility. Here’s a table of their standout choices:
| Model | Type | Output (kW) | Efficiency | Price Range | Best For |
| ecoTEC Plus | Combi | 25-38 | 94% | £1,000-£1,300 | Medium homes, high demand |
| ecoTEC Exclusive | Combi | 30-43 | 94% | £1,200-£1,500 | Premium features, smart app |
| ecoFIT Pure | Combi | 25-35 | 94% | £800-£1,100 | Budget, compact spaces |
| ecoTEC Pro | Combi | 23-30 | 93% | £900-£1,200 | Entry-level, reliable flow |
| aroTHERM Plus | Heat Pump | 3-12 | 200%+ | £4,000-£6,000 | Eco upgrades, renewables |
Trustpilot Reviews for Vaillant Boilers
Vaillant boilers score 4.6/5 on Trustpilot from over 22,575 reviews, with customers praising efficient operation, reliable hot water, and professional support in models like ecoTEC. Positive feedback often highlights quick fixes and bill savings, while negatives occasionally mention delays, but overall satisfaction is high for UK users.
Pros and Cons of Vaillant Boilers
Pros of Vaillant boilers include their innovative tech and eco-focus, offering premium value. Cons may involve higher costs and specific installer requirements.
- Pros:
- Up to 10-year warranties for reassurance.
- High efficiency for savings.
- Advanced smart controls for convenience.
- Low-emission designs for sustainability.
- Strong engineering reputation.
- Cons:
- Pr icier than budget brands.
- Some models require approved installers.
- Shorter base warranties on entry lines.
- Fewer UK sites for parts.
- Occasional variability in support.
Why Consider Viessmann Boilers?
Choose a Viessmann boiler if you prioritise German innovation, high efficiency, and low-emission tech for sustainable heating.
Founded in 1917 in Allendorf, Germany, as a family-owned firm, Viessmann started with steel products and evolved into a global leader in efficient heating, known for pioneering condensing boilers and renewable integration for eco-conscious UK homes.
Viessmann Boilers: Awards
Viessmann boilers have won awards like the HVR Award for Vitocrossal 100 in commercial heating and red dot award for product design in 2025 for Vitodens models. They’ve also earned PLUS X Award for fuel cell heaters and German Innovation Prize for climate-friendly tech, emphasising their role in low-carbon solutions.
Viessmann Boiler Warranty
Viessmann provides up to 10 years warranty with an approved installer for models like Vitodens, offering robust coverage. This term showcases their quality, with heat exchanger extensions up to 10 years for added protection.
Viessmann Popular Boiler Models
Viessmann popular boiler models focus on innovation and compactness, with the Vitodens series leading for efficiency. Here’s a table of their top performers:
| Model | Type | Output (kW) | Efficiency | Price Range | Best For |
| Vitodens 050-W | Combi | 19-35 | 98% | £900-£1,200 | Small homes, budget efficiency |
| Vitodens 100-W | Combi | 11-35 | 98% | £1,000-£1,400 | Medium properties, app control |
| Vitodens 200-W | System/Combi | 1.9-35 | 98% | £1,200-£1,800 | Larger homes, hydrogen-ready |
| Vitodens 111-W | Combi with Storage | 19-35 | 98% | £1,300-£1,600 | High demand, built-in cylinder |
| Vitocal 150-A | Heat Pump | 2-16 | 200%+ | £4,000-£6,000 | Eco upgrades, renewables |
Trustpilot Reviews for Viessmann Boilers
Viessmann boilers score 4.4/5 on Trustpilot from over 5,484 reviews, with customers appreciating efficient performance, quiet operation, and professional support in models like Vitodens. Positive feedback often mentions bill savings and quick installs, while negatives occasionally note parts delays, but overall satisfaction is good for UK users.
Pros and Cons of Viessmann Boilers
Pros of Viessmann boilers include their high efficiency and innovative designs, providing eco-value. Cons may involve higher costs and limited UK presence.
- Pros:
- Up to 98% efficiency for maximal savings.
- Innovative low-NOx tech for green compliance.
- Compact for flexible installs.
- Hydrogen-ready for future-proofing.
- Strong durability in hard water.
- Cons:
- Pr icier than entry-level brands.
- Smaller UK installer network.
- Shorter base warranties.
- Fewer model varieties.
- Occasional support variability.
Viessmann Boilers vs Vaillant Boilers: Which Should You Choose
Viessmann and Vaillant boilers both represent premium German engineering, but your choice depends on efficiency focus versus smart integration. In my expert opinion from installs, select Viessmann for superior efficiency (up to 98%), low emissions, and hydrogen-ready tech if eco-performance and savings are priorities—it’s suited for larger homes or sustainability-driven upgrades with strong durability.
Opt for Vaillant if smart controls, quiet operation, and user-friendly features matter more, ideal for medium properties or tech-savvy users with reliable app integration. For high-demand or green goals, Viessmann wins; for balanced premium, Vaillant excels.
Need a New Boiler Quote?
Looking for a new boiler quote is the next step if you’re ready to upgrade after comparing Viessmann and Vaillant, whether for better efficiency or features in your home or rental. Our experts at Boilers 2 Go are here to assist—request a free new boiler quote today for tailored recommendations on these or other top brands.
FAQs
How do service costs differ between brands?
Vaillant averages £80-£150 annually; Viessmann similar but often includes advanced diagnostics.
What financing is available for these boilers?
Both qualify for 0% interest or green loans if efficient—check installer offers.
Are they hydrogen-ready beyond 20%?
Viessmann tests higher blends; Vaillant focuses on 20% for now.
How do noise levels compare in use?
Vaillant quieter with better insulation; Viessmann solid but startup audible.
Can these support multi-zone heating?
Yes, both integrate with zoning for room-specific control.
I’m Penny North, a home energy heating expert. My mission is to demystify new boilers and complex heating systems to help you achieve a warm, cosy home with lower energy bills and a smaller environmental footprint.