Canada-wide gas boiler information · On-site service in Greater Vancouver, BC
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Comparison
Verdict in brief
The discontinued SSB85 and SSB120 are both 96% AFUE, 5:1 turndown wall-hung stainless condensing boilers with 3/4" gas and 1" water connections. The SSB85 fires 17,060 to 85,300 BTU/hr with a 79 MBH heating capacity and 110 lb weight; the SSB120 fires 23,884 to 119,420 BTU/hr with 110 MBH capacity, 132 lb and a taller 47 1/2 in cabinet.
Published manufacturer figures. Input and output are kept separate; blanks mean the manufacturer did not publish that value.
| Specification | Buderus SSB85 | Buderus SSB120 |
|---|---|---|
| Input, maximum | 85.3 MBH | 119.42 MBH |
| Input, minimum | 17.06 MBH | 23.884 MBH |
| Efficiency (AFUE) | 96 % | 96 % |
| Heating capacity (AHRI) | 79 MBH | 110 MBH |
| Net rating (AHRI) | 69 MBH | 96 MBH |
| Weight (dry) | 110 lb | 132 lb |
| water-volume | — | — |
| Dimensions (W × H × D) | 20 × 39 5/8 × 15 3/8 in (508 × 1006 × 388 mm) | 20 × 47 1/2 × 15 3/8 in (508 × 1206 × 388 mm) |
| Noise rating | 45 dB | 44 dB |
Both sizes share the SSB85/120/160 manual's technical data: ASME Section IV construction, 5:1 turndown, 96% AFUE, 80 psi MAWP, 194 °F maximum operating temperature, 2" vent/air connections, 3/4" NPT gas and 1" water connections.
The ratings scale with input: SSB85 at 17,060-85,300 BTU/hr input, 79 MBH AHRI heating capacity and 69 MBH net rating; SSB120 at 23,884-119,420 BTU/hr, 110 MBH capacity and 96 MBH net rating. Dry weights are 110 lb and 132 lb; dimensions 20 x 39 5/8 x 15 3/8 in against 20 x 47 1/2 x 15 3/8 in.
Both are discontinued and documented in Bosch's US commercial-discontinued archive, with the SSB85/120/160 installation and service manuals still live. Their service manual carries the lockout and blocking error tables extracted in Boilers.ca's batch-10 research.
Bosch Thermotechnology
The Buderus SSB85 is a discontinued wall-hung commercial/residential stainless steel condensing boiler rated 85,300 BTU/hr maximum input with 5:1 turndown, 96% AFUE and 69 MBH net rating.
Bosch Thermotechnology
The Buderus SSB120 is a discontinued wall-hung commercial/residential stainless steel condensing boiler rated 119,420 BTU/hr maximum input with 5:1 turndown, 96% AFUE and 96 MBH net rating.
Yes - both use 2" (60 mm) vent/air connections with CPVC, PVC, PP, PP Flex or stainless steel AL29-4C (IPEX type IIA and IIB).
The AHRI ratings print 79 MBH heating capacity / 69 MBH net for the SSB85 and 110 MBH / 96 MBH for the SSB120, at 96% AFUE.
No. Both are in the discontinued commercial SSB group; the current commercial line is the SSB Gen 1 / Gen 2 family of SSB800, SSB1000 and SSB1000TL modules.
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.