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Viessmann · Vitogas 100 (GS1 / GS10)

Viessmann Vitogas 100 GS10-96

The Vitogas 100 GS10-96 is the largest commercial GS10 boiler: 380 MBH full-load input (111 kW), 325 MBH output and 85.6% combustion efficiency with nine sections.

DiscontinuedHistorically in Canada

Key figures

Max input
Max CSA output
AFUE
Min input
Natural gasPropaneHeating-onlycommercial

Input is gas energy consumed; output is heat delivered. Never size from input alone.

Viessmann Vitogas 100 GS10-96 in practice

The GS10-96 tops the Vitogas 100 commercial range at 380 MBH (111 kW) full-load input and 266 MBH at 70% partial load, with 325 MBH (95 kW) full-load output and a 283 MBH (83 kW) Net I=B=R rating at 85.6% combustion efficiency.

It is the largest GS10 build: nine cast-iron sections, eight burner tubes, 12.8 USG of boiler water and a 1220 mm (48 in) overall width, 1057 mm long and 1088 mm high. The shell weighs 895 lb (406 kg) and the complete boiler 1,194 lb (542 kg), with a nominal 10 in. vent collar and about 125 CFM of combustion and dilution air.

Best suited to

  • Existing GS10-96 installations needing printed ratings
  • The largest Vitogas 100 commercial loads at 380 MBH full-load input
  • Documentation for nine-section GS10 builds

Applicability and support

Model number
GS10-96
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.

See all service areas

Specifications

Published specifications

Values as published by Viessmann. Units are shown with every value; notes flag conflicting sources or missing figures.

Viessmann Vitogas 100 GS10-96 specifications
SpecificationValueNote
Input
CSA input, full load380 MBH111 kW, per the technical data manual
CSA input, partial load (70%)266 MBH78 kW
Output
CSA output, full load325 MBH95 kW
CSA output, partial load (70%)228 MBH67 kW
Net I=B=R rating283 MBH83 kW; based on piping and pick-up allowance of 1.15.
Efficiency
Combustion efficiency85.6 %Printed for all three GS10 sizes.
Venting and air
Vent pipe collar10 inNominal diameter per the technical data manual.
Physical and connections
Weight, boiler shell (as delivered incl. burner)895 lb406 kg
Overall weight (with insulation, burner, control, fittings and draft hood)1,194 lb542 kg
Overall length1,057 mmBoiler shell as delivered is 912 mm (36 in).
Overall width1,220 mm
Overall height1,088 mm43 in; 1227 mm (48 in) with a Vitotronic control.
Operating limits and other
FuelNatural gas or propane7 in. w.c. minimum NG supply pressure; 11 in. w.c. for propane.
Cast iron sections98 burner tubes.
Boiler water content12.8 USG
Maximum operating pressure60 psig4 bar.
Boiler supply / return2 in. NPTMSafety supply 1½ in.; gas supply ¾ in. NPTM.

Frequently asked questions

What is the GS10-96 rated at?

380 MBH (111 kW) full-load input, 266 MBH partial load, 325 MBH (95 kW) full-load output, a 283 MBH Net I=B=R rating and 85.6% combustion efficiency.

How much does the GS10-96 weigh?

The boiler shell ships at 895 lb (406 kg); the complete boiler with insulation, burner, control, fittings and draft hood weighs 1,194 lb (542 kg).

What are the GS10-96 connections?

2 in. NPTM boiler supply and return, 1½ in. safety supply, ¾ in. gas supply and a nominal 10 in. vent pipe collar.

Questions about the Viessmann Vitogas 100 GS10-96?

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.

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