| Grant Combi 70 Mk II | Non-Condensing | Oil | 83.0% |
| Grant Combi 70 V3 | Non-Condensing | Oil | 83.0% |
| Grant Combi 90 Mk II | Non-Condensing | Oil | 83.9% |
| Grant Combi 90 V3 | Non-Condensing | Oil | 82.7% |
| Grant Combi Max | Non-Condensing | Oil | 82.2% |
| Grant Euroflame 90-120 Boilerhouse | Non-Condensing | Oil | 84.4% |
| Grant Euroflame 90-120 Outdoor | Non-Condensing | Oil | 84.4% |
| Grant Euroflame 90-120 System Kitchen Utility | Non-Condensing | Oil | 84.4% |
| Grant Euroflame Boilerhouse 50-70 | Non-Condensing | Oil | 84.7% |
| Grant Euroflame Boilerhouse 70-90 | Non-Condensing | Oil | 84.7% |
| Grant Euroflame Condensing Boilerhouse 50-70 | Condensing | Oil | 90.8% |
| Grant Euroflame Condensing Boilerhouse 70-90 | Condensing | Oil | 90.6% |
| Grant Euroflame Condensing Boilerhouse 90-120 | Condensing | Oil | 90.3% |
| Grant Euroflame Condensing Indoor 50-70 | Condensing | Oil | 90.8% |
| Grant Euroflame Condensing Indoor 70-90 | Condensing | Oil | 90.6% |
| Grant Euroflame Condensing Indoor 90-120 | Condensing | Oil | 90.3% |
| Grant Euroflame Condensing Module 50-70 | Condensing | Oil | 90.8% |
| Grant Euroflame Condensing Module 70-90 | Condensing | Oil | 90.6% |
| Grant Euroflame Condensing Module 90-120 | Condensing | Oil | 90.3% |
| Grant Euroflame Kitchen / Utility 50-70 | Non-Condensing | Oil | 84.7% |
| Grant Euroflame Kitchen / Utility 70-90 | Non-Condensing | Oil | 84.7% |
| Grant Euroflame Kitchen/Utility 90-120 | Non-Condensing | Oil | 84.4% |
| Grant Euroflame Outdoor Module 50-70 | Non-Condensing | Oil | 84.7% |
| Grant Euroflame Outdoor Module 70-90 | Non-Condensing | Oil | 84.7% |
| Grant Euroflame System 50-90 | Non-Condensing | Oil | 84.7% |
| Grant Multipass Boilerhouse 110-140 | Non-Condensing | Oil | 85.4% |
| Grant Multipass Boilerhouse 140-160 | Non-Condensing | Oil | 85.6% |
| Grant Multipass Boilerhouse 160-200 | Non-Condensing | Oil | 85.6% |
| Grant Multipass Boilerhouse 70-90 | Non-Condensing | Oil | 85.6% |
| Grant Multipass Boilerhouse 90-110 | Non-Condensing | Oil | 85.4% |
| Grant Multipass Kitchen 110-140 | Non-Condensing | Oil | 85.4% |
| Grant Multipass Kitchen 140-160 | Non-Condensing | Oil | 85.6% |
| Grant Multipass Kitchen 160-200 | Non-Condensing | Oil | 85.6% |
| Grant Multipass Kitchen 50-70 | Non-Condensing | Oil | 85.6% |
| Grant Multipass Kitchen 70-90 | Non-Condensing | Oil | 85.6% |
| Grant Multipass Kitchen 90-110 | Non-Condensing | Oil | 85.4% |
| Grant Multipass Outdoor 110-140 | Non-Condensing | Oil | 85.4% |
| Grant Multipass System 110-140 | Non-Condensing | Oil | 85.4% |
| Grant Multipass System 50-70 | Non-Condensing | Oil | 85.6% |
| Grant Multipass System 70-90 | Non-Condensing | Oil | 85.6% |
| Grant Multipass System 90-110 | Non-Condensing | Oil | 85.4% |
| Grant Outdoor Combi 90 V3 | Non-Condensing | Oil | 82.7% |
| Grant Outdoor Combi Max | Non-Condensing | Oil | 82.2% |
| Grant Outdoor Combi Mk II | Non-Condensing | Oil | 83.9% |
| Grant Vortex 15 | Condensing | Oil | 91.1% |
| Grant Vortex 15 S | Condensing | Oil | 91.1% |
| Grant Vortex 15-26 Kitchen Boiler | Condensing | Oil | 91.9% |
| Grant Vortex 15-26S Kitchen Boiler | Condensing | Oil | 91.9% |
| Grant Vortex 20 | Condensing | Oil | 91.5% |
| Grant Vortex 20 S | Condensing | Oil | 91.5% |
| Grant Vortex 20G Boilerhouse | Condensing | Oil | 92.9% |
| Grant Vortex 20G Boilerhouse System | Condensing | Oil | 92.9% |
| Grant Vortex 20G Outdoor Module | Condensing | Oil | 92.9% |
| Grant Vortex 20G Outdoor Module System | Condensing | Oil | 92.9% |
| Grant Vortex 20G Utility | Condensing | Oil | 92.9% |
| Grant Vortex 20G Utility System | Condensing | Oil | 92.9% |
| Grant Vortex 26 | Condensing | Oil | 91.9% |
| Grant Vortex 26 S | Condensing | Oil | 91.9% |
| Grant Vortex 26-36 Boilerhouse | Condensing | Oil | 93.3% |
| Grant Vortex 26-36 Boilerhouse System | Condensing | Oil | 93.3% |
| Grant Vortex 26-36 Outdoor Module System | Condensing | Oil | 93.3% |
| Grant Vortex 26-36 Utility Boiler | Condensing | Oil | 93.3% |
| Grant Vortex 26-36-S Utility System Boiler | Condensing | Oil | 93.3% |
| Grant Vortex 30G Boilerhouse | Condensing | Oil | 92.5% |
| Grant Vortex 30G Boilerhouse System | Condensing | Oil | 92.5% |
| Grant Vortex 30G Outdoor Module | Condensing | Oil | 92.5% |
| Grant Vortex 30G Outdoor Module System | Condensing | Oil | 92.5% |
| Grant Vortex 30G Utility | Condensing | Oil | 92.5% |
| Grant Vortex 30G Utility System | Condensing | Oil | 92.5% |
| Grant Vortex 36 | Condensing | Oil | 93.3% |
| Grant Vortex 36S | Condensing | Oil | 93.3% |
| Grant VORTEX BOILERHOUSE 15-21 | Condensing | Oil | 90.8% |
| Grant VORTEX BOILERHOUSE 21-26 | Condensing | Oil | 90.6% |
| Grant VORTEX BOILERHOUSE 26-35 | Condensing | Oil | 90.3% |
| Grant Vortex Condensing Combi 21 | Condensing | Oil | 89.5% |
| Grant Vortex Condensing Combi 26 | Condensing | Oil | 90.2% |
| Grant Vortex Condensing Combi 36 | Condensing | Oil | 91.6% |
| Grant Vortex Eco External 15-21 | Condensing | Oil | 90.8% |
| Grant Vortex Eco External 21-26 | Condensing | Oil | 90.6% |
| Grant Vortex Eco External 26-35 | Condensing | Oil | 90.3% |
| Grant Vortex Eco External System 15-21 | Condensing | Oil | 90.8% |
| Grant Vortex Eco External System 21-26 | Condensing | Oil | 90.6% |
| Grant Vortex Eco External System 26-35 | Condensing | Oil | 90.3% |
| Grant Vortex Eco Utility 15-21 | Condensing | Oil | 90.8% |
| Grant Vortex Eco Utility 21-26 | Condensing | Oil | 90.6% |
| Grant Vortex Eco Utility 26-35 | Condensing | Oil | 90.3% |
| Grant Vortex Eco Utility System 15-21 | Condensing | Oil | 90.8% |
| Grant Vortex Eco Utility System 21-26 | Condensing | Oil | 90.6% |
| Grant Vortex Eco Utility System 26-35 | Condensing | Oil | 90.3% |
| Grant Vortex Eco Wall Hung 12-16 | Condensing | Oil | 91.9% |
| Grant Vortex Eco Wall Hung 16-21 | Condensing | Oil | 91.6% |
| Grant Vortex Eco Wall Hung External 12-16 | Condensing | Oil | 91.9% |
| Grant Vortex Eco Wall Hung External 16-21 | Condensing | Oil | 91.6% |
| Grant Vortex Eco Wall Hung External System 12-16 | Condensing | Oil | 91.9% |
| Grant Vortex Eco Wall Hung External System 16-21 | Condensing | Oil | 91.6% |
| Grant Vortex Eco Wall Hung System 12-16 | Condensing | Oil | 91.9% |
| Grant Vortex Eco Wall Hung System 16-21 | Condensing | Oil | 91.6% |
| Grant Vortex Outdoor Combi 21 | Condensing | Oil | 89.5% |
| Grant Vortex Outdoor Condensing Combi 26 | Condensing | Oil | 90.2% |
| Grant Vortex Outdoor Condensing Combi 36 | Condensing | Oil | 91.6% |
| Grant Vortex Outdoor Module 15-21 | Condensing | Oil | 91.2% |
| Grant Vortex Outdoor Module 15-26 | Condensing | Oil | 91.9% |
| Grant Vortex Outdoor Module 26-36 | Condensing | Oil | 93.3% |
| Grant Vortex Outdoor Module 36-46 | Condensing | Oil | 90.7% |
| Grant Vortex Pro Boilerhouse 36-46 | Condensing | Oil | 90.7% |
| Grant Vortex Pro Boilerhouse 46-58 | Condensing | Oil | 91.7% |
| Grant Vortex Pro Boilerhouse 58-70 | Condensing | Oil | 91.4% |
| Grant Vortex PRO Combi XS 26 | Condensing | Oil | 90.0% |
| Grant Vortex Pro External 46-58 | Condensing | Oil | 91.7% |
| Grant Vortex Pro External 58-70 | Condensing | Oil | 91.4% |
| Grant Vortex Utility 15-21 | Condensing | Oil | 91.2% |
| Grant Vortex Utility 15-26 | Condensing | Oil | 91.9% |
| Grant Vortex Utility 36-46 | Condensing | Oil | 90.7% |
| Grant Vortex Utility 46-58 | Condensing | Oil | 91.7% |
| Grant Vortex Utility 58-70 | Condensing | Oil | 91.4% |
| Grant Vortex Utility System 15-26S | Condensing | Oil | 91.9% |
| Grant Vortex Utility System 36-46S | Condensing | Oil | 90.7% |
