What do you do if you have to replace an old oil boiler with a sustainable, environmentally compatible alternative but a heat pump or a gas connection is not suitable? More than a quarter of all heat generators in Germany are oil heaters. However, almost 4.8 million boilers in the country are outdated and inefficient. It has been confirmed that new oil boilers will have to be installed in combination with renewable energies from 2026.

The new “Future Fuels Ready” condensing boiler Vitoladens 300-C from Viessmann is the right choice for anybody who wants to continue heating with a liquid fuel. Aside from low sulfur fuel oil EL, it can also be operated with greenhouse gas-reduced liquid fuels. This means it has an excellent CO2 footprint with efficiency class A.

HVO, PtL, FAME and conventional fuel oil EL

This proven condensing boiler for single- and two-family homes has also been designed for operation with various greenhouse gas-reduced liquid fuels. Instead of fossil fuel oil HVO (vegetable fuel oil), these include PtL (power-to-liquids) and higher percentages of FAME (fatty acid methyl ester). This results in a saving of up to 5.8 tons of CO2 with fuel oil consumption of 2000 liters. This means that the Vitoladens 300-C is sustainable and can make an important contribution to climate protection.

The new condensing boiler can of course also be combined with a solar heating system. This combination not only eases the burden on the environment – it also allows for a heating energy savings of up to 35 percent. State subsidies of up to 30 percent are also available for the solar heating system.

New design with color selection

The design of the new Vitoladens 300-C is modern and refined. The customer can choose between the colors Vito pearl white or Vito graphite. A DHW cylinder fitted underneath that contains 130, 160 or 200 liters and has the same look completes the compact system.

Revised casing concept simplifies transport

Design changes also included a revision of the casing concept: separate units for the boiler and housing simplify transport and avoid contamination and damage to the high-quality design fronts.

The double encapsulation of the housing helps to significantly reduce noise emissions.

The odor that sometimes occurs during the operation of oil boilers is minimized with integrated oil filters and the double encapsulation of the housing. The connection for the oil line is now on the rear of the device.

Simple maintenance from the front

All maintenance parts (burner, combustion chamber, siphon, dirt separator, oil filter) are accessible from the front. The siphon, dirt separator and oil filter are part of the scope of delivery with the Vitoladens 300-C. The underframe with a height of 40 cm that is also provided offers better accessibility. A design panel for a consistent visual appearance is optionally available.

Safe balanced flue operation

The balanced flue operation with no vent is much easier to install and is more flexible at the installation location. The Vitoladens 300-C is specially licensed for this function. Enhanced condensate drainage that is easy to clean helps to increase operational reliability.

Benefits for trade partners

  • Improved transport with separate design panels
  • Simple maintenance – all maintenance parts are accessible from the front
  • Smooth condensate hoses and dirt separators in the condensate prevent deposits.
  • Condensate lines can be checked and cleaned individually.
  • Optimized and customized accessories
  • Small distributors with metal air vent
  • Additional underframe with a height of 40 cm
  • Low-maintenance and safe operation thanks to the self-sealing siphon with dirt separator

Benefits for users

  • All customary low sulfur fuel oils EL can be used. The following CO2-reduced fuel oils can also be used:
  • Fuel oil DIN SPEC 51603-6-EL A Bio 20: Fuel oil EL low sulfur with admixtures of up to 20 percent biocomponents (FAME)
  • Paraffinic fuel oils (e.g. HVO or PtL) according to DIN TS 51603-8 of up to 100 percent
  • Design housing in Vito pearl white or Vito graphite to choose from
  • Reduced noise levels
  • Reduced odor with integrated oil filter
  • Operation via smartphone using the free ViCare app
  • System monitoring by a specialist partner with Vitoguide

Technical specifications

  • Outputs (two-stage): 12.9 to 19.3; 16.1 to 23.6; 19.3 to 28.9 kW
  • Outputs (modulating): 10.3 to 19.3; 10.3 to 23.6; 12.9 to 28.9 kW
  • Standard utilization rate: 98 percent
  • Liquid fuels: low sulfur fuel oil, HVO, PtL, FAME
  • Dimensions (height x width x depth): 974 x 638 x 1120 mm (10.3 to 23.6 kW)
  • Weight (23.6 kW): 178 kg
  • Energy efficiency category: A

Delivery

The new Vitoladens 300-C is available from May.

Further information

Further information on the new condensing boiler for liquid fuels Vitoladens 300-C can be found on the virtual platform www.viessmann.live