Energy Savings Trust HVO
Vortex Pro: External

5 Year guarantee*

Vortex Pro: External

Each Vortex Pro External oil boiler combines Grant’s proven condensing boiler technology with the latest Riello RDB compact burner.

Grant Vortex Pro External modules offer a factory fitted multi-directional flue, high quality external powder coated casing, built-in frost protection, mains isolating switch and a test switch. Sealed system kits are also available for these oil-fired boilers, and each model has a factory fitted frost stat and condensate state.

a Heating

Features & benefits

  • *5 year guarantee when installed by a G1 Installer (Terms and Conditions apply)
  • Models range in size from 15kW up to 70kW
  • Achieves space heating efficiencies of 90.0 – 94.5%
  • Sealed system kits are available to the 15-21kW, 15-26kW and 26-46kW models
  • Grant’s pre-assembled sealed system kits include: an expansion vessel (size varies), automatic air vent, pressure relief valve and circulating pump. A filling loop and pressure gauge are also supplied as part of the kit. These can be fitted within the module casing, or ideally in a convenient site within the building, located between the cold main and central heating
  • Supplied with a factory fitted, multi-directional flue to help reduce installation time
  • Durable design for all weather conditions
  • Quiet operation
  • As with all of Grant’s Vortex oil boilers, this range is biofuel compatible (depending on the type of biofuel and % blend)
Efficiency through design

Efficiency through design

Grant’s oil boilers incorporate several design features which enable each model to work most efficiently. Each boiler utilises the patented Vortex stainless steel condensing heat exchanger and turbulator baffle system, enabling the boilers to extract energy from the latent heat which would normally be lost through the flue. This award-winning technology has been recognised throughout the industry and it is popular with heating engineers and householders alike.

One of the many reasons installers choose Grant boilers is the choice available, with a boiler to suit many installation applications. View the complete boiler range here.


Product code
Set Output
Max Output
NOx Emissions
Tappings Flow/Return
Energy Rating
Load Profile
Energy Label
Product Fiche
VTXOM15/21 Vortex Pro External 15-21 21kW 21kW 109kg 879mm 385mm 734mm 90.81 Class 2 22mm Riello RDB a Heating - View View
VTXOM15/26 Vortex Pro External 15-26 21kW 26kW 143kg 908mm 505mm 800mm 91.71 Class 2 22mm Riello RDB a Heating - View View
VTXOM26/36 Vortex Pro External 26-36 31kW 36kW 162kg 908mm 505mm 800mm 94.56 Class 2 28mm Riello RDB a Heating - View View
VTXOM36/46 Vortex Pro External 36-46 41kW 46kW 162kg 908mm 505mm 800mm 90.00 Class 2 28mm Riello RDB a Heating - View View
VTXOM46/58 Vortex Pro External 46-58 52kW 58kW 274kg 1240mm 587mm 945mm 91.94 Class 2 1 1/4" BSPmm Riello RDB a Heating - View View
VTXOM58/70 Vortex Pro External 58-70 64kW 70kW 288kg 1240mm 587mm 945mm 91.61 Class 2 1 1/4" BSPmm Riello RDB a Heating - View View


EZ-Fit Flue Range

Grant UK supply a comprehensive range of flue systems to suit all Grant Vortex and VortexBlue oil-fired boiler ranges

View the Range

Home Heating Blog

Discover more about home heating solutions, care and support with our informative blogs

Read more

Looking to develop your product knowledge?

Our award winning Training Academy allows us to offer a wide range of training courses including Grant product training and industry qualifications.

Find out more

Looking to fit and endorse Grant products?

The G1 scheme provides installers with the tools they need to fit and endorse Grant UK products - from training through to marketing support

Find out more

Find a Merchant

Use our national merchant search to find a Grant supplier near you

Find a Merchant


Related products

Compare products
Are you a homeowner? Please click here.