Canada-wide gas boiler information · On-site service in Greater Vancouver, BC
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Comparison
Verdict in brief
The Buderus G315/7 and Buderus G315/8 are both non-condensing boilers in the Bosch Thermotechnology Buderus G315 (Logano G315) line. The Buderus G315/7 is rated 678 MBtu/h gas input, 559 MBtu/h gross output and 84.4% AHRI natural-gas combustion efficiency, and the Buderus G315/8 is rated 801 MBtu/h gas input, 663 MBtu/h gross output and 84.4% AHRI natural-gas combustion efficiency. Buderus G315/8 lists 123 MBtu/h more gas input than Buderus G315/7 (801 MBtu/h against 678 MBtu/h). Both list the same published AHRI natural-gas combustion efficiency of 84.4%. Buderus G315/8 lists 194 lb more shipping weight than Buderus G315/7 (1,779 lb against 1,585 lb).
Published manufacturer figures. Input and output are kept separate; blanks mean the manufacturer did not publish that value.
| Specification | Buderus G315/7 | Buderus G315/8 |
|---|---|---|
| Weight, shipping (approx.) | 1,585 lb | 1,779 lb |
| Allowable fuels | Natural gas, LP, oil #2 | Natural gas, LP, oil #2 |
| Boiler sections | 7 | 8 |
| Gas input | 678 MBtu/h | 801 MBtu/h |
| Oil input | 4.7 GPH | 5.6 GPH |
| Rated gross output | 559 MBtu/h | 663 MBtu/h |
| IBR rating | 486 MBtu/h | 577 MBtu/h |
| Boiler horsepower | 16.6 HP | 19.8 HP |
| AHRI natural-gas combustion efficiency | 84.4 % | 84.4 % |
| AHRI natural-gas thermal efficiency | 82.4 % | 82.8 % |
| AHRI oil combustion efficiency | 87 % | 87.1 % |
| AHRI oil thermal efficiency | 84.9 % | 85.4 % |
| Heating surface | 74.3 sq ft | 86.1 sq ft |
| Maximum allowable working pressure | 87 psig | 87 psig |
| Maximum supply water temperature | 248 °F | 248 °F |
| Water content | 52.6 gal | 60 gal |
| Weight, operating (approx.) | 2,024 lb | 2,280 lb |
| Boiler supply and return | 3" | 3" |
Published ratings: the Buderus G315/7 is rated 678 MBtu/h gas input, 559 MBtu/h gross output and 84.4% AHRI natural-gas combustion efficiency; the Buderus G315/8 is rated 801 MBtu/h gas input, 663 MBtu/h gross output and 84.4% AHRI natural-gas combustion efficiency. Buderus G315/8 lists 123 MBtu/h more gas input than Buderus G315/7 (801 MBtu/h against 678 MBtu/h). Both list the same published AHRI natural-gas combustion efficiency of 84.4%.
Buderus G315/8 lists 194 lb more shipping weight than Buderus G315/7 (1,779 lb against 1,585 lb). The boiler sections differs: the Buderus G315/7 lists 7, while the Buderus G315/8 lists 8. The boiler horsepower differs: the Buderus G315/7 lists 16.6 HP, while the Buderus G315/8 lists 19.8 HP. The heating surface differs: the Buderus G315/7 lists 74.3 sq ft, while the Buderus G315/8 lists 86.1 sq ft.
Both records print the same fuel (Natural gas, LP, oil #2), AHRI natural-gas combustion efficiency (84.4%), maximum allowable working pressure (87 psig) and maximum supply water temperature (248 °F), per the cited sources.
Bosch Thermotechnology
The Buderus G315/7 is a discontinued commercial cast-iron boiler block with 7 sections, 678 MBtu/h gas input (4.7 GPH oil) and a 486 MBtu/h IBR rating.
Bosch Thermotechnology
The Buderus G315/8 is a discontinued commercial cast-iron boiler block with 8 sections, 801 MBtu/h gas input (5.6 GPH oil) and a 577 MBtu/h IBR rating.
The Buderus G315/8 lists 801 MBtu/h, against 678 MBtu/h on the Buderus G315/7, per the cited documentation.
Both list the same AHRI natural-gas combustion efficiency of 84.4%.
It ships at 1,779 lb against 1,585 lb for the Buderus G315/7, per the cited sources.
A consultation includes a heat-loss review so the size is right the first time.
On-site service in Greater Vancouver, BC. ROMA lists “Open 7 days” on its site; call to confirm same-day availability.
Sources and verification
Facts checked September 9, 2026. Last updated September 9, 2026. Technical reviewer: not yet assigned.