6.1 Product description
Gas condensing boiler for natural gas E, LL and LPG
With two return connectors
Also available in sections
For operation with a modulating boiler water temperature
Permissible operating temperature up to 100 °C
Permissible safety temperature up to 110 °C
Permissible operating pressure 6 bar (0.6 MPa)
■ CE designation: CE-0085AU0315 in accordance with the Gas Appli-
ances Directive.
■ Boiler categories: B
23
■ Standard seasonal efficiency [to DIN]: up to
98 % (H
s
) [gross cv] / 109 % (H
i
) [net cv].
■ The stainless steel, corrosion-resistant Inox-Crossal heat exchanger
ensures high operational reliability and a long service life.
■ Inox-Crossal heat exchanger for highly effective heat transfer and
high condensation rate.
■ Self-cleaning effect through smooth stainless steel surface.
■ Clean combustion through low combustion chamber loading and
straight-through design.
■ With either ELCO or Weishaupt pressure-jet gas burner.
■ Two return connectors for hydraulic connection optimised for con-
densing technology.
■ Hydraulically straightforward connection, no minimum flow rate, no
low loss header necessary, particularly low pressure drop on the
water side.
■ Easy to use Vitotronic control unit with plain text and graphic display.
6.2 Operating conditions
Note
For water quality requirements, see page 48.
Requirements
1. Heating water flow rate
None
2. Boiler return temperature (minimum value)
None
3. Low-end boiler water temperature
None
4. Lower boiler water temperature with frost protection
10 °C – ensured through the Viessmann control unit
5. Two-stage burner operation
None
6. Modulating burner operation
None
7. Reduced mode
None – total reduction is possible
8. Weekend setback
None – total reduction is possible
Vitocrossal 300, type CR3B, 787 to 1400 kW
10
VIESMANN
Gas condensing boilers
6
5822 449 GB