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Compare Grant Biomass Boiler Prices & Reviews

Rob Wells
By: Rob Wells
Updated: 24th July 2023

Grant biomass boilers

Grant pride themselves on delivering heating systems that are highly efficient, simple to install and require little maintenance. They're best known for their oil boilers but have since moved into renewable heating systems and are now a biomass boiler manufacturer.

When comparing biomass boilers for your home then you'll need to consider the output rating, efficiency, warranty and potential cost.

  • Output rating: A suitable output rating to match the heating and hot water demands of your home is essential when having a new boiler installed. No matter the fuel. Simply put, the higher the output rating, the more powerful the boiler.This doesn't mean that you should simply have the most powerful boiler installed as this can result in your heating bills being too high. Similarly, an output rating that's too low will be unable to meet the demand.

    Output ratings are measured in kilowatts (kW) and Grant biomass boilers include outputs up to 36 kW and can be extended further by pairing up to 2 Spira units together.

  • Efficiency: So that you can see how well a boiler converts the fuel into heating and hot water, all boilers have an efficiency rating. The efficiency of condensing gas and oil boilers is around 93%. In comparison, Grant biomass boilers achieve efficiencies of 94.8% when the fuel storage is full.
  • Warranty: Knowing that you're protected by the boiler manufacturer after the installation is important and that's where the warranty comes in. Grant biomass boilers are available with a 5 year warranty (when installed by a Grant G1 installer).
  • Price: Biomass boilers are typically more expensive than gas and oil boilers, with Grant biomass boiler prices starting at around £5,699. While biomass boilers tend to be more expensive, you can recoup those costs and even see a return thanks to reduced heating bills (biomass is cheaper than gas and oil) and payments through the Renewable Heat Incentive (RHI) scheme.

Grant biomass boiler fuels

Most domestic biomass boilers run on either wood chips, pellets or logs. And all Grant biomass boilers are designed to run on wood pellets.

Wood pellets are made up of biomass materials compressed into compact tubes, making them easy to store. They're also the most accessible biomass fuel to purchase in the UK.

Grant wood pellet biomass boilers

There are 3 Grant biomass boiler ranges to choose between:

  • Grant Spira
  • Grant Vecta Internal
  • Grant Vecta External

Grant Spira biomass boiler

The Grant Spira range is the most extensive, with 6 different models to choose between including 5-18 kW, 6-26 kW and 9-36 kW. All of these units perform to a highly efficient level and have an ErP A++ efficiency rating as a result.

These are large units installed with a side hopper and pellet feed auger so it's recommended for the unit to be installed within a garage, outhouse or Spirapod (Grant's own outdoor container for the boiler).

Grant Spira Biomass Boiler Output Range (kW) Max. wood pellet storage (kg) Efficiency Warranty
Grant Spira 5-18 110 A++ Up to 5 years
Grant Spira 5-18 200 A++ Up to 5 years
Grant Spira 6-26 110 A++ Up to 5 years
Grant Spira 6-26 200 A++ Up to 5 years
Grant Spira 9-36 110 A++ Up to 5 years
Grant Spira 9-36 200 A++ Up to 5 years

Grant Vecta Internal

The Grant Vecta Internal biomass boiler is a compact alternative to the Grant Spira range and is ideal for a kitchen or utility room installation.

Grant Vecta Internal Biomass Boiler Output Range (kW) Efficiency Warranty
Grant Vecta Internal 4-16 A+ Up to 5 years

Grant Vecta External

The Grant Vecta External is very similar to the Vecta Internal but has been designed for outdoor installation. To withstand the conditions of the outdoors, the Vecta External has built-in frost protection to prevent the water from freezing and has a powder coated paint finish.

Grant Vecta Internal Biomass Boiler Output Range (kW) Efficiency Warranty
Grant Vecta External 4-16 A+ Up to 5 years

Benefits of Grant biomass boilers

Grant biomass boilers are highly efficient heating systems available in a range of outputs to suit almost any property type. Plus, all Grant biomass boilers are available with a 5 year warranty when the installation is carried out by a Grant G1 installer.

Grant Spira benefits

  • Comes with wood pellet storage on the side
  • Two Spira boilers can be installed alongside each other to deliver output ratings of up to 72 kW
  • Fitted with a self-cleaning heat exchanger
  • Boasts a pellet hopper and feed auger so fuel can be automatically fed into the boiler when fuel is needed
  • Save room in your property as the unit is designed for installation in a garage, out house or specially designed SpiraPod

Grant Vecta benefits

  • Internal and external unit options
  • 94.8% efficient with a full fuel load
  • Fitted with a weather compensator which monitors the temperature outside and automatically adjusts the water temperature accordingly
  • An integral wood pellet hopper (60kg) removes the need for a separate hopper to keep the system compact
  • The burner and heat exchanger are self-cleaning

How much do Grant biomass boilers cost?

Grant Spira boilers have the higher price tag than the Vecta range with prices beginning from £7,800 and going up as the units get more powerful.

Grant Biomass Boiler Range Potential Cost (excluding installation)
Grant Spira £7,800 – £9,261
Grant Vecta Internal £5,699
Grant Vecta External £5,899

These prices are for the boiler itself and don't include the cost of installation which will vary from installer to installer.

We can help you find the most competitive price for the installation of a Grant biomass boiler. By completing our online form – simply letting us know that you want a biomass boiler installed – you'll get free quotes from up to 3 local biomass installers. Getting more than a single quote allows you to compare them and hire the installer best suited to the job.

Interested in a biomass boiler?


Get free quotes from a local heating engineer now


Rob Wells

About the author

Rob Wells

Rob is another of our resident home heating experts. He manages our external partnerships, making sure you get the most up to date information.

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