Canada-wide gas boiler information · On-site service in Greater Vancouver, BC
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Comparison
Verdict in brief
Buderus G315/6 and Buderus G315/7 are two non-condensing boilers from the Bosch Thermotechnology Buderus G315 (Logano G315) line. The Buderus G315/6 is documented at 556 MBtu/h gas input, 454 MBtu/h gross output and 84.3% AHRI natural-gas combustion efficiency, while the Buderus G315/7 is documented at 678 MBtu/h gas input, 559 MBtu/h gross output and 84.4% AHRI natural-gas combustion efficiency. Buderus G315/7 lists 122 MBtu/h more gas input than Buderus G315/6 (678 MBtu/h against 556 MBtu/h). Buderus G315/7 carries the higher published AHRI natural-gas combustion efficiency at 84.4%, against 84.3%. Buderus G315/7 lists 194 lb more shipping weight than Buderus G315/6 (1,585 lb against 1,391 lb).
Published manufacturer figures. Input and output are kept separate; blanks mean the manufacturer did not publish that value.
| Specification | Buderus G315/6 | Buderus G315/7 |
|---|---|---|
| Weight, shipping (approx.) | 1,391 lb | 1,585 lb |
| Allowable fuels | Natural gas, LP, oil #2 | Natural gas, LP, oil #2 |
| Boiler sections | 6 | 7 |
| Gas input | 556 MBtu/h | 678 MBtu/h |
| Oil input | 3.85 GPH | 4.7 GPH |
| Rated gross output | 454 MBtu/h | 559 MBtu/h |
| IBR rating | 395 MBtu/h | 486 MBtu/h |
| Boiler horsepower | 13.6 HP | 16.6 HP |
| AHRI natural-gas combustion efficiency | 84.3 % | 84.4 % |
| AHRI natural-gas thermal efficiency | 81.8 % | 82.4 % |
| AHRI oil combustion efficiency | 86.9 % | 87 % |
| AHRI oil thermal efficiency | 84.3 % | 84.9 % |
| Heating surface | 62.4 sq ft | 74.3 sq ft |
| Maximum allowable working pressure | 87 psig | 87 psig |
| Maximum supply water temperature | 248 °F | 248 °F |
| Water content | 45.2 gal | 52.6 gal |
| Weight, operating (approx.) | 1,768 lb | 2,024 lb |
| Boiler supply and return | 3" | 3" |
Published ratings: the Buderus G315/6 is rated 556 MBtu/h gas input, 454 MBtu/h gross output and 84.3% AHRI natural-gas combustion efficiency; the Buderus G315/7 is rated 678 MBtu/h gas input, 559 MBtu/h gross output and 84.4% AHRI natural-gas combustion efficiency. Buderus G315/7 lists 122 MBtu/h more gas input than Buderus G315/6 (678 MBtu/h against 556 MBtu/h). Buderus G315/7 carries the higher published AHRI natural-gas combustion efficiency at 84.4%, against 84.3%.
Buderus G315/7 lists 194 lb more shipping weight than Buderus G315/6 (1,585 lb against 1,391 lb). The boiler sections differs: the Buderus G315/6 lists 6, while the Buderus G315/7 lists 7. The boiler horsepower differs: the Buderus G315/6 lists 13.6 HP, while the Buderus G315/7 lists 16.6 HP. The heating surface differs: the Buderus G315/6 lists 62.4 sq ft, while the Buderus G315/7 lists 74.3 sq ft.
Both records print the same fuel (Natural gas, LP, oil #2), maximum allowable working pressure (87 psig), maximum supply water temperature (248 °F) and boiler supply and return (3"), per the cited sources.
Bosch Thermotechnology
The Buderus G315/6 is a discontinued commercial cast-iron boiler block with 6 sections, 556 MBtu/h gas input (3.85 GPH oil) and a 395 MBtu/h IBR rating.
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.
The Buderus G315/7 lists 678 MBtu/h, against 556 MBtu/h on the Buderus G315/6, per the cited documentation.
The Buderus G315/7 carries the higher published AHRI natural-gas combustion efficiency at 84.4%, against 84.3%.
It ships at 1,585 lb against 1,391 lb for the Buderus G315/6, 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.