Canada-wide gas boiler information · On-site service in Greater Vancouver, BC
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Bosch Thermotechnology · Series
The Buderus GB312 (Logano plus GB312) is a discontinued commercial natural-gas condensing boiler with an aluminum heat exchanger, sold in six sectional sizes from GB312/90 to GB312/280 with 305 to 944 MBH gross IBR output and 91.7-93.1% thermal efficiency. Its manuals now sit in Bosch's US discontinued commercial-boiler library.
Series facts
The GB312 series brochure prints per-size thermal efficiency from 93.1% (GB312/90) down to 91.7% (GB312/280); the manual's I-B-R table prints input, gross output and net rating without an AFUE row.
The GB312 is a European-designed, gas-fired condensing boiler with an aluminum heat exchanger and 4 to 8 heat-exchanger sections. Its brochure rates the line from 305 MBH (GB312/90) to 944 MBH (GB312/280) gross IBR output with 328.3 to 1,028.8 MBH gas input and 93.1% to 91.7% thermal efficiency; the installation and service manual prints the I-B-R input, gross output and net rating tables plus 50 psi MAWP, 180 °F maximum supply temperature and a 200 °F manual-reset high limit.
The GB312 is no longer in Bosch's Canadian or US catalogs. Its installation/service manual, operating manual and applications manual are published from the US 'Commercial Products - Discontinued' archive, and the brochure from the discontinued Buderus literature library. Boilers.ca documents the line as historical so owners can find the ratings and the manual set. The manual's chapter 10 carries a discrete fault-display table (display code plus numeric fault code) for the MC10/SAFe control system.
Highlights
Models
One canonical page per model with input, output and efficiency kept separate.
Bosch Thermotechnology
The Buderus GB312/90 is a discontinued commercial natural-gas condensing boiler with an aluminum heat exchanger, 4 sections, 328.3 MBH maximum input and 305 MBH gross IBR output at 93.1% thermal efficiency.
Bosch Thermotechnology
The Buderus GB312/120 is a discontinued commercial natural-gas condensing boiler with an aluminum heat exchanger, 4 sections, 440.5 MBH maximum input and 409 MBH gross IBR output at 92.8% thermal efficiency.
Bosch Thermotechnology
The Buderus GB312/160 is a discontinued commercial natural-gas condensing boiler with an aluminum heat exchanger, 5 sections, 588.3 MBH maximum input and 544 MBH gross IBR output at 92.5% thermal efficiency.
Bosch Thermotechnology
The Buderus GB312/200 is a discontinued commercial natural-gas condensing boiler with an aluminum heat exchanger, 6 sections, 732.6 MBH maximum input and 676 MBH gross IBR output at 92.3% thermal efficiency.
Bosch Thermotechnology
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.
Bosch Thermotechnology
The Buderus GB312/280 is a discontinued commercial natural-gas condensing boiler with an aluminum heat exchanger, 8 sections, 1,028.8 MBH maximum input and 944 MBH gross IBR output at 91.7% thermal efficiency.
| Specification | Buderus GB312/90 | Buderus GB312/120 | Buderus GB312/160 | Buderus GB312/200 | Buderus GB312/240 | Buderus GB312/280 |
|---|---|---|---|---|---|---|
| I-B-R input, minimum | 132.2 MBH | 132.2 MBH | 176.5 MBH | 219.8 MBH | 264.2 MBH | 308.6 MBH |
| I-B-R input, maximum | 328.3 MBH | 440.5 MBH | 588.3 MBH | 732.6 MBH | 880.7 MBH | 1,028.8 MBH |
| output-max | — | — | — | — | — | — |
| afue | — | — | — | — | — | — |
| turndown | — | — | — | — | — | — |
| vent-max-3 | — | — | — | — | — | — |
| vent-max-2 | — | — | — | — | — | — |
| Weight | 455 lb | 455 lb | 530 lb | 585 lb | 665 lb | 730 lb |
Read the full comparison: Buderus GB312/90 vs GB312/160 →
Read the full comparison: Buderus GB312/200 vs GB312/280 →
Read the full comparison: Buderus GB312/90 vs Buderus GB312/120 →
Read the full comparison: Buderus GB312/120 vs Buderus GB312/160 →
Error codes and alerts
Manuals
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.
Services for Bosch Thermotechnology boilers
No. The GB312 does not appear in Bosch's current Canadian or US boiler catalogs; its documentation is published from the US 'Commercial Products - Discontinued' archive and the discontinued Buderus products library.
Six: GB312/90, GB312/120, GB312/160, GB312/200, GB312/240 and GB312/280, with 4, 4, 5, 6, 7 and 8 heat-exchanger sections respectively.
The official installation and service manual prints natural-gas (gas type A) ratings only, with a natural-gas orifice diameter. No LP conversion or LP rating table appears in that manual, so Boilers.ca lists the GB312 as a natural-gas series.
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
Facts checked September 9, 2026. Last updated September 9, 2026. Technical reviewer: not yet assigned.