What is the quietest boiler?

Boiler manufacturers usually show their decibel rating (dB) in sales brochures and manufacturer’s manuals.

For example, the Vaillant EcoTec range noise level is 49 dB and the Worcester Bosch Green Star 25i is 53 dB.

To put that into context, refrigerators are considered to be around 40 dB, rainfall 50 dB, a washing machine 70 dB and 110 dB(A) for a football crowd.

In most cases, older boilers will tend to have noisy fans due to wear and tear. One of the quietest combi boilers in the market currently is the Grant Vortex Pro 26, while the Viessmann Vitodens 200 boiler is amongst the quietest condensing boilers.

The Grant Vortex Pro 26

The Vortex Pro 26 Floor Standing ErP is a compact and exceptionally quiet boiler with a noise level of 41 dB. This 26kW combi boiler was designed with the engineer in mind. It’s simple and quick to install and doesn’t need complicated wiring or plumbing.


  • Large plate heat exchangers reduce water content. The increased surface area offers improved hot water performance
  • Safety features include a low system pressure cut-off switch which protects the boiler in the event of system water loss
  • Two accurate electronic temperature controls allow the boiler to operate condensing mode on central heating whilst maintaining instant hot water production
  • New models have internal frost protection, neon diagnostic indicators and a factory fitted internal condensate trap.

Viessmann Vitodens 200

The Vitodens 200-W is a high specification gas fired hot water boiler, and is one of the most efficient and quietest condensing boilers in its class. With noise emissions of 36 dB, it’s no doubt one of the quietest boilers on the market. Viessmann’s fantastic reputation as one of Europe’s largest manufacturer of boilers means you can rely on their products.


  • Low emission combustion with Viessmann made stainless steel Matrix cylinder burner
  • Extremely quiet operation – quieter than most refrigerators
  • Uses a “No Permanent Pilot Light” ignition system
  • Wall mounted fast installation and reduced maintenance with Lambda Pro
  • Compact, aesthetically pleasing product design and zero clearance to combustibles
  • Inox-Radial heat exchanger surface and Matrix-compact burner.

Vaillant EcoTec Pro Range

This combi boiler is ideal for small to medium-sized homes that do not have a high level of hot water use. Additionally, all of Vaillant’s boilers are Quiet Mark approved (the international award programme that encourages companies to design technology with noise reduction in mind) and their quality boilers can last for over a decade.


  • A heating output of 24kW and hot water output of 30kW can efficiently heat and supply hot water to a medium-sized three bedroom house
  • You can fit it on your kitchen wall or hide it in a storage cupboard
  • This boiler is Quiet Mark accredited and has a noise level of 49 dB
  • The patented ‘Aquacomfort’ system gives you access to instant hot water at regular temperatures
  • The Pro 30 has 7 years guarantee when fitted by a Vaillant accredited installer.

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