Wolf CGB-75 Installation And Technical Manual page 14

Note:
Provide a BDF valve at the lowest system point.
Safety equipment
The minimum system pressure is 1.0 bar.
The gas condensing boiler is approved exclusively for sealed
systems of up to 6 bar. The maximum flow temperature is
factory-set to 80 °C and may be adjusted to 90 °C if required.
Generally, the flow temperature is 80 °C for DHW operation.
Heating water
General requirements
There is a risk of damage to the boiler resulting
from water leaks, poor heat transfer or
corrosion.
- Before connecting the gas condensing boiler, flush the
heating system to remove residues such as welding pearls,
hemp, putty, sludge sediments, etc. from the pipework
- Clean the dirt trap
- The automatic air vent valve for the appliance must be
opened during operation
- The max. flow rate of 100 l/min (6000 l/m³) must not be
exceeded
- Domestic hot water or partially desalinated domestic hot
water should be used as fill water and top-up water
- If an ingress of oxygen cannot be ruled out, a system
separation is advisable
- Heating water pH value must be between 6.5 and 8.5
- Limitation of the fill water hardness:
Min. 2 °dH, max. 11 °dH, at > 10 l/kW see Design information,
water treatment
- De-scaling using single-stage ion exchangers is not
permissible. For permissible methods, see Design
information, water treatment
- Inhibitors and antifreeze are not permissible
- A system log must be kept (see Design information, water
treatment)
Additional requirements for operation without a low loss
header
- Systems with only one CGB-75/100
14
Installation
- Sludge separator in the boiler return of the CGB-75/100
- Desalination of the heating water to < 3 °dH
- Control of the cylinder heating only via the MM module
- Cylinder primary pump at least DN 25 with at least 6 m
- The max. flow temperature must be adjusted with parameter
The manufacturer does not assume liability for any damage to
the heat exchanger caused by oxygen diffusion in the heating
water. In the event of oxygen penetrating the system, we
recommend a system separation through the interconnection
of a heat exchanger.
Information on scaling
Scaling can be strongly influenced particularly through the
method of commissioning. Heat the system at the lowest output
with an even and adequate throughput. For multi-boiler systems
it is recommended to commission all boilers simultaneously to
prevent the overall amount of lime concentrating on the heat
exchanger surface of an individual boiler.
(configurations 1 and 10)
head
HG08 to 75 °C
The design information for water treatment must
be observed, otherwise system damage due to
water leaks may occur.
Before commissioning, all hydraulic pipes must
undergo a tightness test:
Test pressure on heating water side max. 8
bar.
Prior to testing, close the shut-off valves in
the heating circuit for the appliance, because
otherwise, the safety valve (accessory) opens
at 3 bar. The appliance has already been tested
at the factory for tightness at 6 bar.
If the appliance is not watertight, there is a risk
of leaks and resulting material losses.
The maximum flow rate must not exceed
6000 l/h (100l/min).
30 62 555_0709