Click Here To Choose Your Local Branch
  My Account   Sign In or Register

Use My Location
Branch Availability Straight Line Distance
Please enter your delivery postcode



Email Offers


Plumbase Customer Services

01285 715407

To find your nearest branch contact details,
please select a branch.



Grand Total: £0.00
Basket Is Empty

Grant Vortex Pro 15-26kW External Oil Boiler

Part Number : H015217

Enter your delivery postcode for stock availablity.


Boiler Type

  • External Oil-Fired Condensing Boiler
  • Sleek Casing
  • Exceptionally Quiet Operation

Grant Vortex Pro 15-26kW External Oil Boiler

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.

Features and Benefits:

  • External Oil-Fired Condensing Boiler
  • Sleek Casing
  • Exceptionally Quiet Operation
  • Fitted with Tried and Trusted Riello RDB Lo-NOx Burner
  • Unique Grant Vortex Stainless Steel Heat Exchanger
  • Factory-Fitted Multi-Directional Flue
  • Built-in Frost Protection
  • 26kW Max Output
  • Annual Efficiency: 91.71% (Gross SAP2009)
  • Size: 908mm x 505mm x 734mm (HWD)
  • 5 Year Manufacturer Guarantee (When Installed by a G1 Accredited Installer)

Technical Specifications

Manufacturer Guarantee 5 Years
Max Heat Output 26
Boiler Type Regular/Heat Only Boiler
Manufacturer Part Number VTXOM15/26

Frequently Asked Questions

  • What is the difference between the Grant Vortex boiler and the Grant VortexBlue boiler?

    The Grant Vortex boiler range uses a low NOx yellow flame burner, whereas the Grant VortexBlue boilers uses an ultra-Lox blue flame burner. The combustion head on the VortexBlue’s burner is specially designed to re-circulate the combustion gases. Re-circulating the combustion gases in this way significantly reduces NOx emissions and produces the clean blue flame which gives the technology its name.

  • What size of boiler do I need?

    Before selecting your new boiler, Grant recommend requesting that your installer performs a heat loss estimation of your home to ensure that you select the most appropriate size and type of boiler. Heat loss depends on the efficiency of any heat retaining methods that can be implemented in your home, for example loft insulation, double glazing, cavity wall insulation, draught proofing, etc. These practises could mean that your new boiler may need to be smaller than the one that it is replacing.

  • Can I run a new Grant Vortex boiler on an older heating system?

    As long as the system is thoroughly cleansed and updated to fully pumped operation, it is possible to run a Grant oil boiler on an older heating system.

  • Can I use my existing flue system for my new Grant boiler?

    Unfortunately, in most cases you will not be able to use an existing flue system with a new boiler. Condensing boilers have a lower flue gas temperature which can lead to harmful condensation in the chimney/flue. You will need to ensure that you install a Grant approved flue system which is stainless steel and sealed securely at the joints to prevent it from leaking. All Grant external modules come with a factory fitted flue system.

  • How often should a Grant boiler be serviced?

    Grant recommend that an oil boiler operating on kerosene should be serviced every twelve months, and an oil boiler operating on biofuel or gas oil should be serviced bi-annually.

  • I’m worried that my oil supply could run out, how would this affect my system?

    Grant recommend keeping your oil tank filled as required to ensure that the oil does not run out. If your oil supply does run out, you should contact a qualified oil heating engineer to bleed the system once the tank has been filled. It is recommended that after filling, a period of about an hour is allowed for any sediment that has been disturbed in the oil tank time to settle before operating the boiler. With an oil boiler, there is a risk of air and contaminants that sit in the bottom of your oil tank (water and sludge) reaching the oil line and ultimately the burner. This will affect the operation of your boiler, however maintaining an adequate oil level in the tank can prevent this from happening and causing further damage.

  • What coating is applied to Grant Vortex Pro External casings?

    Grant’s Vortex Pro External boilers have a high-quality external powder coated casing. This is a durable material designed to provide protection against the weather and elements. Each boiler also has an insulated weatherproof enclosure made of galvanised steel.

  • What type of base should a Grant Vortex Pro External boiler be installed upon?

    Vortex Pro External modules must be installed on a solid, level surface which is capable of supporting the weight of the boiler when full of water. For example, a prepared concrete standing, paving slabs bedded down on sand or cement, or something similar.

  • What type of flue should I fit with a Grant Vortex Pro External boiler?

    Grant’s Vortex Pro External boilers are supplied with a factory fitted low level discharge flue system. This scan be adjusted on site for either rear, left hand or right hand flue outlet position as required. Alternative Grant flue systems are also compatible.

  • What type of cylinder can Grant Vortex Pro External oil boilers be installed with?

    The Vortex Pro External modules are automatic pressure jet oil boilers which have been designed for use with a fully pumped central heating system with an indirect domestic hot water cylinder. Please note, these boilers are not suitable with a direct cylinder, ‘primatic’ cylinder or gravity hot water.

  • If I install a new Grant Vortex Pro External oil boiler, do I need new radiators?

    All of Grant’s Vortex Pro External boilers will operate at extremely high efficiencies even when they are nor in condensing mode. Each boiler is therefore suitable to be fitted to an existing heating system without alternation to the radiator sizes. Please note, the heating system may need cleaning and power flushing.

  • How much clearance should be left around the installed unit?

    With all Grant Vortex Pro External boilers, adequate clearance must be left around the boiler. Grant recommends that a minimum clearance of 600mm above the boiler is left to allow for the removal of the top panel and 600mm at each end to allow access to the burner and condensate trap. Providing sufficient clearance will enable engineers easy access for service and maintenance of the product in the future.

For more information on the delivery options for your postcode area and our returns policy please visit:

Delivery and Returns

We use cookies to help give you the best experience on our website. If you continue without changing your settings, we'll assume that you are happy to receive all cookies on the website. However, you can read our Cookie Policy here.

Accept and Continue