- Fuel type
Natural gas (NG) or liquid propane gas (LPG)
- Min. input
19,000 BTU (5.6 kW) for CU3A-94
25,000 BTU (7.3 kW) for CU3A-125
43,000 BTU (12.6 kW) for CU3A-160 & CU3A-199
- Max. input
94,000 BTU (27.5 kW) for CU3A-94
125,000 BTU (36.6 kW) for CU3A-125
160,000 BTU (47 kW) for CU3A-160
199,000 BTU (58 kW) for CU3A-199
- Efficiency (AFUE)
95% for all models
269 lbs (122 kg) for CU3A-94
275 lbs (125 kg) for CU3A-125
352 lbs (160 kg) for CU3A-160 & CU3A-199
- Overall dimensions
27 inches (684 mm) for CU3A-94 & CU3A-125
31½ inches (801 mm) for CU3A-160 & CU3A-199
26 inches (660 mm) for all models
61½ inches (1562 mm) for all models, with control interface closed
67 inches (1707 mm) for all models, with control interface open
Limited lifetime warranty in residential applications. See warranty sheet for details.
Exceptional performance and flexibility
Advanced condensing technology
Vitocrossal 300 CU3A is a gas-fired floor-standing boiler with stainless steel Inox-Crossal heat exchanger and MatriX dome gas burner. Rated input: 19 to 199 MBH.
95% AFUE rating on all models.
High temperature capability
Operating temperature up to 194°F (90°C).
High water volume extends burner run time and reduces short cycling.
Extremely clean combustion
And 5:1 turndown ratio with MatriX dome gas burner.
Durable and long service life
With Inox-Crossal stainless steel heat exchanger and high mass design.
Multiple venting options and configurations with vent lengths up to 198 ft.
The right choice for new construction or retrofits
With its combination of high temperature capability, high mass (water volume), floor standing design, condensing stainless steel construction and modulating gas burner, the Vitocrossal 300, CU3A is the ideal choice for boiler retrofits or new construction. From homes equipped with high mass cast iron radiators, to homes with multi-zone high temperature fin tube radiators, and new installations with high DHW requirements – the Vitocrossal 300, CU3A is the best choice on the market today.
Intelligent combustion control
The proven MatriX dome gas burner with Lambda Pro combustion control automatically adjusts to fluctuating gas qualities and ensures a consistently high combustion efficiency for both natural gas and propane gas.
Exceptional performance and reliability
The vertical stainless steel Inox-Crossal heat exchanger offers ideal conditions for intensive utilization of hot gases, resulting in efficiencies of up to 98%. The smooth stainless steel surfaces allow the condensate created by the condensing process to simply run off downwards. This creates a permanent self-cleaning effect, ensuring high efficiency, long service life and reduced maintenance.
With a limited lifetime warranty in residential applications, you can be sure your investment will deliver long-lasting value year after year. For detailed terms and conditions, see the warranty sheet.
Advantages of the Vitocrossal 300 CU3A
Look inside the boiler
- Vitotronic 200 control with graphical user interface.
- Water-cooled combustion chamber.
- Modulating MatriX dome gas burner.
- Inox-Crossal heat exchanger.
- Highly effective thermal insulation.
- Flue gas collector with condensate drain pipe.
- Combustion air inlet connection.