viessmann vs worcester

Viessmann boilers vs Worcester Bosch boilers, who do we think is better?

Worcester Bosch and Viessmann are two premium choices when it comes to domestic boilers. Both are high quality and built for high efficiency. Here we will look at them both and see which is the better brand, overall. To start, a brief introduction to both.

Worcester Bosch

Worcester Bosch started life in Worcester, 1962, and was founded by Cecil Duckworth the company was originally known as Worcester Engineering Co Ltd. The company is now a subsidiary of Robert Bosch GmbH, a Germany based manufacturer.

The company product range includes hot water cylinders, heat pumps, gas and oil boilers and solar water heating systems.

A household name, the company is the current market leader in the UK for its domestic boiler range. There is however a strong contender nipping at its heels and gaining ground year on year.


Viessmann was founded in 1917, and it has been family-owned in Germany from the start. The company now operates in 74 countries, producing heating, industrial and refrigeration systems. Having operated in the UK since 1989, the company produces biomass boilers, steam boilers, heat pumps and combined heat power generation.

The company trains around 2,500 architects, installers, specifiers and contractors for its products across the UK. Parts for Viessmann boilers are widely available for purchase by the general public in Plumbase stores.

Viessmann stands out from Worcester Bosh in another area – its entire range of Vitodens boilers has been awarded Which? Best Buy status, every single year, from 2017.

Thoughts on the Worcester Bosch boilers

To sum up, the Bosch boiler range is impressive but how do various points stand up?

● Guarantee. The guarantees are pretty comprehensive but last just 5 years. It covers replacement parts, callouts and labour. The low life of the guarantee is a letdown, but it can be extended if certain points are met – one of them being the boiler will cost more.
● Manual override. If the thermostat should fail, the manual override can be a lifesaver on a cold night.
● Simple controls. There is nothing complicated about the controls on these boilers, and everything is easy to find.
● Freezing. There is a very low risk of condensate pipe freezing in cold weather.
● Frost protection. This reduces the risk of frost forming in a cold location (garage, loft etc.)

Thoughts on the Viessman boiler range

As the second-largest, and growing, boiler manufacturer in Europe how do their products stand up?

● Innovative. Viessmann invests heavily in its product innovation, across its whole range, with the boilers having cutting-edge, future proof technology as standard.
● Whisper quiet. As an example, the Vitodens 200-W has an operating volume of just 36dB – this makes it one of the quietest boilers on the market – this is quieter than a refrigerator.
● Efficiency. This is key to the whole boiler range and is a direct result of the huge amounts of investment in innovation. No boiler the Viessmann produces has an efficiency rating lower than 93%, and the 200-W and 222-F both are rated at 98% efficiency.
● Weather compensation. All of the boilers from Viessmann’s Vitodens range come equipped with this technology. This works by the way of an outdoor sensor, using this the boiler can regulate the temperature automatically.
● 10-year warranty. Viessmann does offer a 5-year warranty, but if installed by a Viessmann trained installer, this is doubled.

Final thoughts and verdict

The clear winner here is Viessmann, there’s no question. Both manufacturers produce quality products, but the sheer quality of the components of Viessmann boilers is what pushes them over the line.

Viessmann, in contrast to Worcester Bosch, does not use any plastic components in their boilers. They also do not use aluminium heat exchangers. Viessmann uses stainless steel for their heat exchangers and the difference is almost palpable.

The fact that these boilers also have weather compensation technologies, which is going to help keep energy bills down, is also a winning feature. Without a doubt, if you are looking for a new boiler, it has to be a Viessmann.

Quantum Gas Engineering Ltd. Are Accredited Viessmann installers.

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