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Vokera Unica MAX S Boiler

Vokera’s Unica MAX S is a natural gas and LPG compatible system boiler that requires a cylinder to provide hot water storage.

The Unica MAX S from Vokera is a high-efficiency system boiler designed to enhance the lives of homeowners and heating engineers and accept a methane-hydrogen blend when the local network eventually switches over. It comes with a generous warranty, has an affordable price tag and boasts a good range of controls and features. Furthermore, this system boiler can run on natural gas or LPG without needing a conversion kit. 

How Much Does this Boiler Cost?

Available in outputs of 20kW and 30kW, the Unica MAX S will set you back anything between £845 and £905, including VAT. This does not include installation costs, which vary significantly depending on the company you choose to carry out the installation and the amount of work involved. We recommend you get a quote from local and national installers to compare prices and find a good deal. 

How will I know if this Boiler is Suitable for My Home?

System boilers, like the Vokera Unica MAX S, are ideal for medium and large-sized homes with more than one bathroom and a high demand for hot water. They take up more space than combi boilers because they require a separate hot water storage cylinder but, unlike regular boilers, take water directly from the mains and don’t need tanks in the loft. 

Choosing the right boiler size is not an easy task, plus you must select the correct boiler type for your home. Even if you have a general idea of the best boiler type and output for your needs, you should still ask a Gas Safe registered engineer to help you. 

Is it a High Efficiency Boiler?

The Unica MAX S from Vokera is an A-rated system boiler with an ErP efficiency of 94%, making it one of the most efficient on the market. It comes with a high-efficiency modulating pump and can operate with 20% hydrogen mixed with methane, making it ready for when the UK’s gas network makes the switch. 

Does this Boiler have a Good Range of Controls and Features?

Vokera’s Unica MAX S models feature a colour liquid crystal display user interface with a text menu control and an optional embedded time clock that programmes the heating on and off times. This system boiler has a large bore radial stainless steel heat exchanger, high-efficiency modulating pump and ACC (active combustion control) to reduce admissions by adapting the air/gas mix according to the gas quality. It also has OpenTherm inside, a built-in filling loop, and a click fit flue connection.  

How long is the Warranty on this Boiler?

You will receive a generous 10-year warranty as standard when you purchase the Vokera Unica Max S and choose a Gas Safe registered engineer to install it. 

Summary of Important Information

  • Expect to pay between £845 and £905
  • Heating output of 20kW or 30kW 
  • 20kW unit dimensions: 740mm (H) x 420mm (W) x 275mm (D)
  • 30kW unit dimensions: 740mm (H) x 470mm (W) x 350mm (D)
  • Uses natural gas or LPG as its fuel source
  • A-rated for efficiency
  • 10-year warranty as standard

Pros and Cons

It’s difficult to say anything negative about the budget-friendly Vokera Unica MAX S system boiler with a decent set of controls and a lengthy warranty. The only downside is that, like all system boilers, it requires enough space for a hot water storage cylinder. Below, you can read our list of pros and cons. 


  • Considerably cheaper than some other boiler brands
  • Suited to medium and large-sized homes 
  • Easy to install, use and service
  • High modulation
  • Back-lit LCD display enables full control of heating times over the week
  • High-efficiency modulating pump
  • Combustion air filter protects the boiler from pollution
  • Large bore stainless steel heat exchanger – enables front servicing and reduced installation clearances
  • OpenTherm inside
  • Horizontal, vertical and twin flue options available
  • Approved for use with a hydrogen/methane blend (20/80)
  • Excellent rating on Trustpilot – correct at the time of writing – January 2022
  • 10-year warranty


  • Requires separate cylinder
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