Viessmann · Vitogas 100 (GS1 / GS10)
Viessmann Vitogas 100 GS1-60
The Vitogas 100 GS1-60 is the largest GS1 boiler: 240 MBH input (70 kW), 203 MBH output and 85.4% AFUE on an eight-section, nine-burner chassis.
Key figures
- Max input
- —
- Max CSA output
- —
- AFUE
- 85.4 %
- Min input
- —
Input is gas energy consumed; output is heat delivered. Never size from input alone.
Viessmann Vitogas 100 GS1-60 in practice
The GS1-60 tops the GS1 range at 240 MBH (70 kW) input, 203 MBH (60 kW) output and a 177 MBH (52 kW) Net I=B=R rating at 85.4% AFUE — the lowest printed AFUE in the series. It is the widest GS1 build at 1110 mm (43¾ in), with eight cast-iron sections and nine burners.
Weight is 582 lb (264 kg) with 5.8 USG of boiler water at 60 psig maximum operating pressure. It shares the GS1 platform's atmospheric, chimney-vented design with draft hood and vent damper; full documentation lives in Viessmann Canada's historic manuals.
Best suited to
- Existing GS1-60 installations needing printed ratings
- The largest GS1 loads at up to 240 MBH input
- Documentation for the top GS1 size before the commercial GS10 range
Applicability and support
- Model number
- GS1-60
- 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 (natural gas) | 240 MBH | 70 kW, per the technical data manual |
| Output | ||
| CSA output / DOE heating capacity | 203 MBH | 60 kW |
| Net I=B=R rating | 177 MBH | 52 kW; based on piping and pick-up allowance of 1.15. |
| Efficiency | ||
| Efficiency (AFUE) | 85.4 % | With intermittent pilot electronic ignition and vent damper. |
| Venting and air | ||
| Vent pipe collar | Per model | 5 to 7 in. outside diameter per the technical data manual. |
| Physical and connections | ||
| Weight (boiler with insulation, burner and control) | 582 lb | 264 kg |
| Overall length | 864 mm | Printed as 34 in; heights 33¼ in (845 mm) with control in operating position. |
| Overall width | 1,110 mm | Printed as 43¾ in |
| Overall height (operation) | 845 mm | 33¼ in; 955 mm with control in operation position, 1180 mm for servicing. |
| Operating limits and other | ||
| Fuel | Natural gas or propane | 5 in. w.c. minimum NG supply pressure; 11 in. w.c. for propane. |
| Cast iron sections | 8 | 9 burners. |
| Boiler water content | 5.8 USG | |
| Maximum operating pressure | 60 psig | |
| Boiler supply / return | 1½ in. male thread | Gas supply ½ in. NPT. |
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 GS1-60 rated at?
240 MBH (70 kW) input, 203 MBH (60 kW) output, a 177 MBH (52 kW) Net I=B=R rating and 85.4% AFUE.
Why is the GS1-60's AFUE slightly lower than the smaller GS1 sizes?
The technical data manual prints 85.4% for the GS1-60 against 85.5-85.6% for the smaller sizes — the figures as printed, all with intermittent pilot electronic ignition and a vent damper.
How heavy is the GS1-60?
582 lb (264 kg) with insulation, burner and boiler control, with 5.8 USG of boiler water content.
Questions about the Viessmann Vitogas 100 GS1-60?
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
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- Viessmann Vitogas 100 GS1-48Same series
- Viessmann Vitogas 100 GS10-72Same series
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- Viessmann Vitogas 100 GS10-96Same series
- Vitogas 100 (GS1 / GS10) series hub
- Buying guide
Sources and verification
- Technical Data Manual — Vitogas 100 GS1 Series, doc 5167 462 v1.5 · 5167 462 v1.5 · 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.