Vortex Pro: External

5 Year guarantee*

Vortex Pro: External

The Grant Vortex Pro range has some of the highest energy efficiency ratings in the UK which not only significantly lowers fuel bills but also considerably reduces greenhouse gas emissions and lessens the environmental impact of domestic hot water and heating systems. They incorporate the latest Riello low NOx burner technology with Grant’s patented heat exchangers to give an award winning range that meets the 2018 low NOx emission targets.

a Heating

Features & benefits

The Grant Vortex Pro external models combine our existing proven condensing boiler technology with the latest Riello RDB low NOx compact burner.

The Vortex Pro Range of external modules offers the same unique features as the Eco External modules including the factory fitted multi-directional flue, high quality external powder coated casing, built in frost protection, mains isolating switch and a test switch. However, in addition, the boilers have a higher efficiency level and are factory wired to receive an ‘optional’ RF (radio frequency) wireless programmer. In this situation, the receiver can be plugged into the control panel of the module, enabling the boiler to be operated using a remote controller from any room inside the house, without the need for hard wiring.

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Sealed System Kits

The Grant Pro range of Standard Vortex external modules can be converted to sealed system operation by purchasing a pre-assembled kit from Grant UK. The sealed system kit includes 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 return.

  • Compliant with September 2018 low NOx legislation
  • Outputs ranging from 15-70kW
  • 90.7- 93.3% Gross SAP2009 annual efficiency
  • 5 year guarantee when installed by a G1 accredited installer (T&C’s apply)
  • Factory-fitted multi-directional flue
  • Built-in frost protection
  • Fitted with tried and trusted Riello RDB Lo-NOx burner
  • Unique Grant Vortex stainless steel heat exchanger
  • Exceptionally quiet operation
Low NOx Ready

Low NOx Ready

On 26th September 2018, the next phase of the EU’s Energy-related Products Directive will come into effect. New legislation will set maximum nitrogen oxides (NOx) emission levels that space heaters will need to meet, reducing the overall NOx emissions produced from heating. For oil-fired boilers, the NOx emissions target will be a maximum of 120mg/kWh so all oil boilers placed on the market by the manufacturer on or after 26th September will need to be compliant.


One of the overarching objectives of the new legislation is to help improve the air quality by reducing pollution. In response to both Government regulations and a growing demand from homeowners, manufacturers have continuously explored ways to make their products more efficient and sustainable. The good news is that advances with burner technology coupled to Grant’s efficient boiler designs have enabled all of our Vortex Pro and Eco boiler ranges to achieve these new targets with virtually no visible change to the existing line up.

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Configure your flue

We have a wide range of options available when it comes to flue systems, here's a helpful hand to put the right flue with the right boiler.

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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



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