Viessmann · Vitogas 100 (GS1 / GS10)
Viessmann Vitogas 100 GS10-84
The Vitogas 100 GS10-84 is the mid-size commercial GS10: 340 MBH full-load input (100 kW), 291 MBH output and 85.6% combustion efficiency with eight sections and seven burner tubes.
Key figures
- Max input
- —
- Max CSA output
- —
- AFUE
- —
- Min input
- —
Input is gas energy consumed; output is heat delivered. Never size from input alone.
Viessmann Vitogas 100 GS10-84 in practice
The GS10-84 steps the commercial range to 340 MBH (100 kW) full-load input and 238 MBH at 70% partial load, with 291 MBH (85 kW) full-load output and a 253 MBH (74 kW) Net I=B=R rating at 85.6% combustion efficiency.
It adds a section and a burner tube over the GS10-72 — eight sections and seven burners — and grows to 1120 mm (44 in) overall width while keeping the 1007 mm length and 1088 mm height. Water content rises to 11.4 USG; the shell weighs 805 lb (365 kg) and the complete boiler 1,036 lb (470 kg).
Best suited to
- Existing GS10-84 installations needing printed ratings
- Commercial loads between the GS10-72 and GS10-96
- Documentation for eight-section GS10 builds
Applicability and support
- Model number
- GS10-84
- 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 Viessmann. Units are shown with every value; notes flag conflicting sources or missing figures.
| Specification | Value | Note |
|---|---|---|
| Input | ||
| CSA input, full load | 340 MBH | 100 kW, per the technical data manual |
| CSA input, partial load (70%) | 238 MBH | 70 kW |
| Output | ||
| CSA output, full load | 291 MBH | 85 kW |
| CSA output, partial load (70%) | 204 MBH | 60 kW |
| Net I=B=R rating | 253 MBH | 74 kW; based on piping and pick-up allowance of 1.15. |
| Efficiency | ||
| Combustion efficiency | 85.6 % | Printed for all three GS10 sizes. |
| Venting and air | ||
| Vent pipe collar | 9 in | Nominal diameter per the technical data manual. |
| Physical and connections | ||
| Weight, boiler shell (as delivered incl. burner) | 805 lb | 365 kg |
| Overall weight (with insulation, burner, control, fittings and draft hood) | 1,036 lb | 470 kg |
| Overall length | 1,007 mm | Boiler shell as delivered is 912 mm (36 in). |
| Overall width | 1,120 mm | |
| Overall height | 1,088 mm | 43 in; 1227 mm (48 in) with a Vitotronic control. |
| Operating limits and other | ||
| Fuel | Natural gas or propane | 7 in. w.c. minimum NG supply pressure; 11 in. w.c. for propane. |
| Cast iron sections | 8 | 7 burner tubes. |
| Boiler water content | 11.4 USG | |
| Maximum operating pressure | 60 psig | 4 bar. |
| Boiler supply / return | 2 in. NPTM | Safety supply 1½ in.; gas supply ¾ in. NPTM. |
Manuals
- Technical Data Manual — Vitogas 100 GS1 Series, doc 5167 462 v1.55167 462 v1.5 · 2011-02
- Installation Instructions — Vitogas 100 GS1, rev 1.31.3 · 2011-02
- Technical Data Manual — Vitogas 100 GS10 Series, doc 5167 466 v1.35167 466 v1.3 · 2011-02
- Service Instructions — Vitogas 100 GS10, rev 1.11.1 · 2007-11
Alerts documented for this model
None documented yet.
Frequently asked questions
What is the GS10-84 rated at?
340 MBH (100 kW) full-load input, 238 MBH partial load, 291 MBH (85 kW) full-load output, a 253 MBH Net I=B=R rating and 85.6% combustion efficiency.
How wide is the GS10-84?
1120 mm (44 in) overall, 1007 mm (37 in) long and 1088 mm (43 in) high, at 1,036 lb (470 kg) complete.
What vent collar does the GS10-84 use?
A nominal 9 in. vent pipe collar with approximately 115 CFM of combustion and dilution air.
Questions about the Viessmann Vitogas 100 GS10-84?
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.
Compare and explore
- Viessmann Vitogas 100 GS10-72 vs GS10-84Comparison
- Viessmann Vitogas 100 GS10-84 vs GS10-96Comparison
- Viessmann Vitogas 100 GS1-22Same series
- Viessmann Vitogas 100 GS1-29Same series
- Viessmann Vitogas 100 GS1-35Same series
- Viessmann Vitogas 100 GS1-42Same series
- Viessmann Vitogas 100 GS1-48Same series
- Viessmann Vitogas 100 GS1-60Same series
- Viessmann Vitogas 100 GS10-72Same series
- Viessmann Vitogas 100 GS10-96Same series
- Vitogas 100 (GS1 / GS10) series hub
- Buying guide
Sources and verification
- Technical Data Manual — Vitogas 100 GS10 Series, doc 5167 466 v1.3 · 5167 466 v1.3 · accessed September 9, 2026
- Viessmann Canada — Historic manuals · accessed September 9, 2026
Facts checked September 9, 2026. Last updated September 9, 2026. Technical reviewer: not yet assigned.