3.1 Product description
Gas condensing boiler with MatriX radiant burner for natural gas E and
LL
With two return connectors
For operation with a modulating boiler water temperature
Permissible operating temperature up to 95 °C
Permissible safety temperature up to 110 °C
Permissible operating pressure 4 bar (0.4 MPa)
■ CE designation: CE-0085BN0569 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].
■ Stainless steel Inox-Crossal heat exchanger for efficient utilisation
of condensing technology – self-cleaning effect through smooth
stainless steel surfaces.
■ Modulating MatriX gas burner with a wide modulation range (30 to
100 %) for particularly quiet, economical and environmentally
responsible operation.
■ Excellent controllability and reliable heat transfer due to wide water
galleries and high water content.
■ Second return connector for low return temperatures resulting in an
especially intensive utilisation of condensing technology.
■ Easy to use Vitotronic control unit with plain text and graphic display.
■ Hydraulically straightforward connection, no minimum flow rate, no
low loss header necessary, particularly low pressure drop on the
water side.
■ A strong draught in the flue outlet enables long flue and ventilation
air pipe runs.
3.2 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 CM3, 87 to 142 kW
Gas condensing boilers
VIESMANN
7
5822 449 GB
3
