Grant oil boilers · Oxfordshire
Grant oil boilers in Oxfordshire
Grant G1 installers and OFTEC registered oil-heating engineers. Explore Vortex Pro, Vortex Eco, combi and external oil boilers, with up to 10-year guarantees and a carefully planned installation.
Grant boilers, chosen around your home
For Grant oil boilers in Oxfordshire, choose a local team that understands off-mains heating. First, we assess your property, hot-water use and existing oil supply. Then, we help you choose the right Vortex boiler and provide a clear quotation for your installation.
As Grant G1 installers, we offer up to 10-year guarantees on Grant Vortex Pro oil boilers. In addition, we fit and register your installation through the G1 scheme, giving you a complete service from survey to handover.
Explore the Grant boiler range
First, compare the Grant boiler ranges below, using the images and key facts alongside each description. Then, open the model specifications to see the published figures, or ask our team to explain the choices for your home.
Oil boilers
Oil regular
Vortex Pro: External
For Grant oil boilers, our survey checks the appliance position and the complete heating system. The Pro External range combines a weather-resistant casing with built-in frost protection. Therefore, we consider it when you want to move the appliance outside and recover useful space indoors.
Compare model specifications
| Product code | Model | Set Output | Max Output | Weight | Height | Width | Depth | Efficiency | NOx Emissions | Energy Rating |
|---|---|---|---|---|---|---|---|---|---|---|
| VTXOM15/26 | Vortex Pro External 15-26 | 21kW | 26kW | 143kg | 908mm | 505mm | 800mm | 91.71 | Class 2 | a Heating |
| VTXOM26/46 | Vortex Pro External 26-46 | 41kW | 46kW | 162kg | 910mm | 505mm | 796mm | 90.00 | Class 2 | a Heating |
| VTXOM46/70 | Vortex Pro External 46-70 | 64kW | 70kW | 288kg | 1239mm | 586mm | 947mm | 91.61 | Class 3 | a Heating |
Oil regular
Vortex Pro: Internal
First, compare these Grant oil boilers with the space and hot water your home needs. The white-cased Pro Internal family includes heat-only and sealed-system arrangements. In addition, a range of outputs helps us match the boiler to smaller homes or larger heating demands.
Compare model specifications
| Product code | Model | Set Output | Max Output | Weight | Height | Width | Depth | Efficiency | NOx Emissions | Energy Rating |
|---|---|---|---|---|---|---|---|---|---|---|
| VTX15/26 | Vortex Pro 15-26 | 21kW | 26kW | 130kg | 860mm | 470mm | 603mm | 91.71 | Class 2 | a Heating |
| VTX26/46 | Vortex Pro 26-46 | 41kW | 46kW | 144kg | 898mm | 470mm | 602mm | 90.00 | Class 2 | a Heating |
| VTX46/70 | Vortex Pro 46-70 | 64kW | 70kW | 282kg | 1234mm | 563mm | 782mm | 91.61 | Class 3 | a Heating |
| VTXS15/26 | Vortex Pro System 15-26 | 21kW | 26kW | 138kg | 860mm | 470mm | 603mm | 91.71 | Class 2 | a Heating |
| VTXS26/46 | Vortex Pro System 26-46 | 41kW | 46kW | 168kg | 898mm | 470mm | 602mm | 90.00 | Class 2 | a Heating |
Oil combi
Vortex Pro: External Combi
Before choosing Grant oil boilers, discuss the range and installation layout with our oil-heating team. The external combi family offers 21, 26 and 36kW models in a weather-resistant casing. In addition, built-in frost protection supports an installation that frees up indoor space.
Compare model specifications
| Product code | Model | Set Output | Max Output | Weight | Height | Width | Depth | Efficiency | NOx Emissions | Energy Rating |
|---|---|---|---|---|---|---|---|---|---|---|
| VTXOMCOMBI21 | Vortex Pro External Combi 21 | 21kW | 21kW | 181kg | 945mm | 658mm | 754mm | 90.81 | Class 2 | a Heating b Water |
| VTXOMCOMBI26 | Vortex Pro External Combi 26 | 26kW | 26kW | 206kg | 945mm | 658mm | 754mm | 91.71 | Class 2 | a Heating b Water |
| VTXOMCOMBI36 | Vortex Pro External Combi 36 | 36kW | 36kW | 225kg | 945mm | 658mm | 754mm | 94.56 | Class 2 | a Heating b Water |
Oil combi
Vortex Pro: Internal Combi
For Grant oil boilers, our survey checks the appliance position and the complete heating system. The internal combi family includes 21, 26 and 36kW models, plus the slimline 26kW Combi XS. At 515mm wide, the XS provides another option where installation space is limited.
Compare model specifications
| Product code | Model | Set Output | Max Output | Weight | Height | Width | Depth | Efficiency | NOx Emissions | Energy Rating |
|---|---|---|---|---|---|---|---|---|---|---|
| VTXCOMBI21 | Grant Vortex Pro Combi 21 | 21kW | 21kW | 160kg | 860mm | 614mm | 614mm | 90.81 | Class 2 | a Heating b Water |
| VTXCOMBI26 | Grant Vortex Pro Combi 26 | 26kW | 26kW | 177kg | 860mm | 614mm | 614mm | 91.71 | Class 2 | a Heating b Water |
| VTXCOMBI36 | Grant Vortex Pro Combi 36 | 36kW | 36kW | 200kg | 900mm | 614mm | 614mm | 94.56 | Class 2 | a Heating b Water |
| VTXXSCOMBI26 | Grant Vortex Pro Combi XS 26 | 26kW | 26kW | 163kg | 857mm | 515mm | 606mm | 92.00 | Class 2 | a Heating b Water |
Oil regular
Vortex Eco: Internal Wall Hung
First, compare these Grant oil boilers with the space and hot water your home needs. A heat-only oil boiler provides heat for your radiators and a separate hot-water cylinder. First, we check the controls, circulation and oil supply, then plan a neat replacement.
Compare model specifications
| Product code | Model | Set Output | Max Output | Weight | Height | Width | Depth | Efficiency | NOx Emissions | Energy Rating |
|---|---|---|---|---|---|---|---|---|---|---|
| VTXWH16/21 | Grant Vortex Eco Wall Hung 16-21 | 18.7kW | 21kW | 85.7kg | 842mm | 630.5mm | 335.5mm | 90.52 | Class 2 | a Heating |
| VTXSWH16/21 | Grant Vortex Eco Wall Hung System 16-21 | 18.7kW | 21kW | 97.5kg | 842mm | 630.5mm | 335.5mm | 90.52 | Class 2 | a Heating |
Oil regular
Vortex Boiler House
Before choosing Grant oil boilers, discuss the range and installation layout with our oil-heating team. The distinctive red Boiler House range suits garages, cellars and plant rooms. Therefore, it offers a practical choice where a kitchen-style white casing is less important than access and layout.
Compare model specifications
| Product code | Model | Set Output | Max Output | Weight | Height | Width | Depth | Efficiency | NOx Emissions | Energy Rating |
|---|---|---|---|---|---|---|---|---|---|---|
| VTXBH15/26 | Grant Vortex Boiler House 15-26 | 21kW | 26kW | 125kg | 891mm | 431mm | 594mm | 91.70 | Class 2 | a Heating |
| VTXBH26/46 | Grant Vortex Boiler House 26-46 | 41kW | 46kW | 145kg | 877mm | 455mm | 591mm | 90.06 | Class 2 | a Heating |
| VTXBH46/70 | Grant Vortex Boiler House 46-70 | 64kW | 70kW | 301kg | 1078mm | 542mm | 765mm | 91.66 | Class 3 | a Heating |
Oil regular
Vortex Eco: External Wall Hung
For Grant oil boilers, our survey checks the appliance position and the complete heating system. A heat-only oil boiler provides heat for your radiators and a separate hot-water cylinder. First, we check the controls, circulation and oil supply, then plan a neat replacement.
Compare model specifications
| Product code | Model | Set Output | Max Output | Weight | Height | Width | Depth | Efficiency | NOx Emissions | Energy Rating |
|---|---|---|---|---|---|---|---|---|---|---|
| VTXOMWH16/21 | Grant Vortex Eco Wall Hung External 16-21 | 18.7kW | 21kW | 92.1kg | 832mm | 684mm | 351mm | 90.52 | Class 2 | a Heating |
| VTXSOMWH16/21 | Grant Vortex Eco Wall Hung External System 16-21 | 18.7kW | 21kW | 96.1kg | 832mm | 684mm | 351mm | 90.52 | Class 2 | a Heating |
Oil regular
Vortex Eco: Internal
First, compare these Grant oil boilers with the space and hot water your home needs. A heat-only oil boiler provides heat for your radiators and a separate hot-water cylinder. First, we check the controls, circulation and oil supply, then plan a neat replacement.
Compare model specifications
| Product code | Model | Set Output | Max Output | Weight | Height | Width | Depth | Efficiency | NOx Emissions | Energy Rating |
|---|---|---|---|---|---|---|---|---|---|---|
| VTXECO15/21 | Grant Vortex Eco Utility 15-21 | 21kW | 21kW | 97kg | 860mm | 430mm | 605mm | 92.7 | Class 2 | a Heating |
| VTXECO21/26 | Grant Vortex Eco Utility 21-26 | 23.5kW | 26kW | 97kg | 860mm | 430mm | 605mm | 91.7 | Class 2 | a Heating |
| VTXECO26/35 | Grant Vortex Eco Utility 26-35 | 31kW | 35kW | 127kg | 900mm | 470mm | 603mm | 92.4 | Class 2 | a Heating |
| VTXSECO15/21 | Grant Vortex Eco Utility System 15-21 | 21kW | 21kW | 123kg | 860mm | 430mm | 605mm | 92.7 | Class 2 | a Heating |
| VTXSECO21/26 | Grant Vortex Eco Utility System 21-26 | 23.5kW | 26kW | 123kg | 860mm | 430mm | 605mm | 91.7 | Class 2 | a Heating |
| VTXSECO26/35 | Grant Vortex Eco Utility System 26/35 | 31kW | 35kW | 138kg | 900mm | 470mm | 603mm | 92.4 | Class 2 | a Heating |
Oil regular
Vortex Eco: External
Before choosing Grant oil boilers, discuss the range and installation layout with our oil-heating team. A heat-only oil boiler provides heat for your radiators and a separate hot-water cylinder. First, we check the controls, circulation and oil supply, then plan a neat replacement.
Compare model specifications
| Product code | Model | Set Output | Max Output | Weight | Height | Width | Depth | Efficiency | NOx Emissions | Energy Rating |
|---|---|---|---|---|---|---|---|---|---|---|
| VTXOMECO15-21 | Grant Vortex Eco External 15-21 | 21kW | 21kW | 113kg | 908mm | 505mm | 800mm | 92.7 | Class 2 | a Heating |
| VTXOMECO21-26 | Grant Vortex Eco External 21-26 | 23.5kW | 26kW | 113kg | 908mm | 505mm | 800mm | 91.7 | Class 2 | a Heating |
| VTXOMECO26/35 | Grant Vortex Eco External 26-35 | 31kW | 35kW | 142kg | 908mm | 505mm | 800mm | 92.4 | Class 2 | a Heating |
| VTXSOMECO15/21 | Grant Vortex Eco External System 15-21 | 21kW | 21kW | 136kg | 908mm | 505mm | 800mm | 92.7 | Class 2 | a Heating |
| VTXSOMECO21/26 | Grant Vortex Eco External System 21-26 | 23.5kW | 26kW | 136kg | 908mm | 505mm | 800mm | 91.7 | Class 2 | a Heating |
| VTXSOMECO26/35 | Grant Vortex Eco External System 26-35 | 31kW | 35kW | 152kg | 908mm | 505mm | 800mm | 92.4 | Class 2 | a Heating |
Compare figures carefully, because manufacturers publish different units and test conditions. For example, hot-water flow at a 35°C temperature rise differs from a figure measured at 40°C. In addition, ErP efficiency and seasonal efficiency to DIN use different test methods. Therefore, we explain the relevant figures before matching the exact model to your quotation.
What matters when choosing Grant boilers?
First, we calculate your home’s heating requirement, because radiator numbers alone cannot tell us the right boiler output. In addition, we compare the boiler’s minimum output so it can respond to smaller heating demands.
Next, we assess hot water, because the available water supply and temperature rise affect a combi’s flow at your taps. By contrast, a cylinder-based system needs the right storage capacity and recovery. Therefore, we discuss your showers, baths and daily routine together.
Also, we check the installation space, service access, flue route and controls. Although case dimensions are useful, the installation needs working room around the appliance too. As a result, your quotation covers a complete, practical boiler replacement.
Choose the right Grant boiler type
Oil combi boilers
An oil combi combines heating and hot-water production in one appliance. Therefore, we assess your water supply, hot-water demand and the practical position of the boiler.
Discuss your boiler type →Oil regular boilers
A heat-only oil boiler provides heat for your radiators and a separate hot-water cylinder. First, we check the controls, circulation and oil supply, then plan a neat replacement.
Discuss your boiler type →External oil boiler
An external boiler can release useful space indoors. First, we assess its base, flue, pipework route and access, then plan the oil supply and controls.
Discuss your boiler type →Oil heating expertise for off-mains homes
Grant oil boilers provide a dedicated option for homes away from the mains-gas network. First, we check the existing oil tank, supply line, boiler location and heating arrangement. Then, we explain whether an internal, external, combi or cylinder-based Vortex installation suits the property.
In addition, Grant’s floor-standing Vortex range is HVO compatible with the correct conversion work. Therefore, we explain what this means for your appliance and the wider fuel supply. However, the current wall-hung models have their own specification, so we assess them separately.
Your Grant boiler installation, step by step
Survey your home
First, we discuss your rooms, heating and hot-water use. Also, we inspect the boiler, supply, radiators and controls, so your Grant boiler installation has a clear starting point.
Compare the options
Next, we explain suitable ranges, outputs and controls. Therefore, your quotation sets out the chosen boiler, fitting work and any system changes. You can then decide with a clear picture of the work.
Prepare and fit carefully
Then, we prepare the heating system and address cleaning and filtration. In addition, we fit the boiler, flue, pipework and controls with attention to service access and the finished appearance.
Commission and hand over
Finally, we test and commission the appliance, complete the records and explain the settings. Also, we show you the heating schedule and everyday controls, then help you arrange ongoing servicing.
INDEPENDENTLY REVIEWED
Heating work backed by hundreds of five-star reviews
For example, customers repeatedly mention punctual engineers, tidy workmanship and clear advice before, during and after their heating project.
The gas-boiler service was completed efficiently and the certificate arrived by email almost immediately.
An older-property boiler upgrade finished on time, with tidy workmanship, punctual attendance and a flexible approach.
A last-minute boiler service was arranged quickly and completed efficiently by a team the customer readily recommends.
Review totals checked September 2026. Read the complete independent feedback on Google and Which? Trusted Traders.
Grant boiler questions
Can Oxyplumb install a Grant boiler?
We install Grant boilers across Oxfordshire, including straightforward replacements and wider heating upgrades. First, tell us about your current appliance so we can understand what you want to improve.
Which boiler output should I choose?
First, consider your home’s heating demand and hot-water use. Therefore, we assess the property, water supply and existing system before recommending an output. After all, the largest model is not automatically the right choice.
Can you replace a boiler from another brand?
Your existing boiler can be from another brand, because we plan the replacement around your heating system. First, we inspect the system, explain the options and quote for the work needed to fit your chosen Grant replacement.
Do you service and repair other boiler makes?
Our maintenance work also covers a broad range of boiler manufacturers, including older and less familiar makes. First, tell us your boiler’s make, model and fuel, so we can arrange the right engineer.
Local Grant boiler installation and ongoing care
For example, our team covers Faringdon, Wantage, Abingdon, Stanford in the Vale, Oxford, Bampton, Clanfield, Witney, Cumnor, Carterton, Uffington and Kingston Bagpuize. Choose your area to find its dedicated installation, servicing and repair pages.
Also, we maintain and repair boilers from a broad range of manufacturers. Explore our boiler servicing and boiler repair services, or compare our other manufacturer guides below.
Ready to choose your new Grant boiler?
First, tell Oxyplumb about your home and the work you have in mind. Then, we will help you choose the right boiler and provide a clear installation quotation.