Bosch Thermotechnology · Buderus GB312 (Logano plus GB312)
Buderus GB312/240
The Buderus GB312/240 is a discontinued commercial natural-gas condensing boiler with an aluminum heat exchanger, 7 sections, 880.7 MBH maximum input and 810 MBH gross IBR output at 92% thermal efficiency.
Key figures
- Max input
- 880.7 MBH
- Max CSA output
- —
- AFUE
- —
- Min input
- 264.2 MBH
Input is gas energy consumed; output is heat delivered. Never size from input alone.
Buderus GB312/240 in practice
Best suited to
Applicability and support
- Model number
- GB312/240
- Canadian availability
- historical
- Production status
- discontinued
- ROMA supplies
- Confirmed at consultation
- ROMA services
- Confirmed at consultation
- Warranty
- Not verified
Where ROMA provides on-site service
On-site service is currently offered in Greater Vancouver, BC, including Vancouver, Burnaby, Richmond, Surrey, Coquitlam, North Vancouver, West Vancouver, New Westminster, Port Coquitlam, Port Moody, Delta, Langley, Maple Ridge, Abbotsford, Chilliwack, White Rock, Pitt Meadows, Tsawwassen, Anmore, Lions Bay, Belcarra, Bowen Island, Mission. Everything else on this site is reference information you can use anywhere in Canada.
Specifications
Published specifications
Values as published by Bosch Thermotechnology. Units are shown with every value; notes flag conflicting sources or missing figures.
| Specification | Value | Note |
|---|---|---|
| Input | ||
| I-B-R input, maximum | 880.7 MBH | 880,700 BTU/hr (natural gas, gas type A). |
| I-B-R input, minimum | 264.2 MBH | 264,200 BTU/hr. |
| Output | ||
| I-B-R gross output (180/80 °F) | 810 MBH | Brochure prints gross IBR output; the manual prints 305,000 to 944,000 BTU/hr across the range. |
| I-B-R net rating (180/80 °F) | 705 MBH | |
| Efficiency | ||
| Thermal efficiency | 92 % | Series brochure per-size row. |
| Combustion efficiency | 92.2 % | Series brochure per-size row. |
| Venting and air | ||
| Vent connection | 8" | Category IV condensing, positive pressure; balanced flue uses a 3.94" combustion air pipe. |
| Physical and connections | ||
| Heat-exchanger sections | 7 | Aluminum heat exchanger; ASME Boiler and Vessel Code Section IV. |
| Maximum allowable working pressure | 50 psi | 50 psi per the manual specifications table. |
| Maximum supply temperature | 180 °F | The manual's high-temperature cut-out safety limit is 200 °F, manual reset. |
| Weight | 665 lb | 302 kg; transport dimensions in the manual. |
| Boiler water capacity | 7.1 US gal | 26.9 l. |
| Operating limits and other | ||
| Boiler horsepower | 24.2 HP | |
| Gas connection | 1 1/4" NPT | |
| Supply and return connections | 2 1/2" NPT | |
| Fuel | Natural gas (gas type A) | The official manual prints natural-gas ratings only. |
Manuals
Alerts documented for this model
Questions about the Buderus GB312/240?
Describe what the boiler is doing and get a straight answer about the next step.
On-site service in Greater Vancouver, BC. ROMA lists “Open 7 days” on its site; call to confirm same-day availability.
Sources and verification
- Logano plus GB312 Installation and Service Instructions (6 720 806 273) · accessed September 9, 2026
- Buderus GB312 Series Brochure · accessed September 9, 2026
- Bosch Home Comfort US — Commercial Products - Discontinued: Discontinued Boilers · accessed September 9, 2026
Facts checked September 9, 2026. Last updated September 9, 2026. Technical reviewer: not yet assigned.