- Fuel type
Natural gas (NG) or liquid propane gas (LPG)
- Min. input (single fuel NG)
250,000 BTU (73 kW) for CA3B 2.5
300,000 BTU (88 kW) for CA3B 3.0, 3.5, 5.0
400,000 BTU (117 kW) for CA3B 4.0, 6.0
- Max. input (single fuel NG)
2,500,000 BTU (733 kW) for CA3B 2.5
3,000,000 BTU (879 kW) for CA3B 3.0
3,500,000 BTU (1026 kW) for CA3B 3.5
4,000,000 BTU (1172 kW) for CA3B 4.0
5,000,000 BTU (1465 kW) for CA3B 5.0
6,000,000 BTU (1758kW) for CA3B 6.0
- Thermal efficiency *
96.1% for all models
* Tested to ANSI/AHRI standard 1500 Performance Rating of Commercial Space Heating Boilers / DOE Test Procedure 81 FR 89276 / U.S. Standards ANSI Z21.13/CSA 4.9 / AHRI, BTS-2000 Testing Standard Method to determine the efficiency of Commercial Heating Boilers.
- Weight (single fuel boiler)
4233 lbs (1920 kg) for CA3B 2.5, 3.0
4696 lbs (2130 kg) for CA3B 3.5
4806 lbs (2180 kg) for CA3B 4.0
6261 lbs (2840 kg) for CA3B 5.0
6894 lbs (3127 kg) for CA3B 6.0
- Overall dimensions (single fuel boiler)
88¾ inches (2251 mm) for CA3B 2.5, 3.0
99½ inches (2526 mm) for CA3B 3.5, 4.0
136 inches (3449 mm) for CA3B 5.0, 6.0
34 inches (860 mm) for CA3B 2.5, 3.0
39½ inches (1000 mm) for CA3B 3.5, 4.0, 5.0, 6.0
78¾ inches (2000 mm) for CA3B 2.5, 3.0
84 inches (2131 mm) for CA3B 3.5, 4.0, 5.0, 6.0
Limited 10 year commercial warranty. See warranty sheet for details.
- More details
Vitocrossal 300 CA3B
Outstanding versatility, performance and reliability
Vitocrossal 300 CA3B
Our most powerful gas condensing boiler
Vitocrossal 300 CA3B is a commercial gas-fired condensing boiler with stainless steel Inox-Lamellar heat exchanger and fully-modulating burners. Rated input: 2500 to 6000 MBH.
Low emissions & quiet operation
With fully-modulating Viessmann pre-mix cylinder burners (up to 3).
Easy fuel changeover
From NG to LP with a simple turn of a key (on Dual Fuel models).
Fully assembled boiler
Simplifies installation and commissioning.
Large water content
Reduces wasteful burner cycling which increases system efficiency and overall durability.
With building management systems.
Venting through the sidewall or chimney, and combustion air options of sealed combustion or room dependent.
Advanced condensing technology and flexibility
With its unique synthesis of proven Viessmann technology and innovative features, the Vitocrossal 300 CA3B takes a bold step forward while retaining the superior Viessmann quality you know and trust.
The boiler combines unparalleled flexibility with maximum efficiency, making it your ideal choice for a new installation or economical retrofit in multi-family, commercial or light industrial applications.
Exceptional performance and reliability
The titanium-stabilized stainless steel Inox-Lamellar heat exchanger surface provides maximum heat extraction while maintaining a compact size. Its smooth, corrosion-resistant surfaces allow condensate to simply run off – a "self-cleaning" process that ensures continuous condensing efficiency, reduced maintenance costs and longevity.
Combined with our fully-modulating pre-mix cylinder burners, the Vitocrossal 300 CA3B achieves outstanding thermal efficiencies over 96% and delivers exceptional performance and reliability at an attractive price.
User-friendly control system
The Vitotronic 300, GW6C control system is an advanced digital boiler and system control with outdoor reset function that ensures reliable, efficient performance of the entire heating system. The Vitotronic 300 GW6C will modulate input and rotate boilers to meet the heating system's load. The control will regulate supply water temperature for one high temperature circuit, two mixing valve circuits and one DHW circuit with the standard control package.
A versatile solution
With multiple venting options and seamless integration into building management systems, the Vitocrossal 300 CA3B offers a solution for almost every commercial application. The boiler comes fully assembled and is easy to install. For buildings with narrow entrances or small elevators, the boiler can be disassembled into sections to fit.
Check out the time-lapse video below to see the installation process in action at the First Canadian Place in Toronto.
Advantages of the Vitocrossal 300 CA3B
Look inside the boiler
- Vitotronic 300, GW6C control system
- Fully-modulating cylinder burners
- Inox-Lamellar heat exchanger surfaces
- Highly effective thermal insulation
- Wide water passageways