Wolf CGB-75 Installation And Operating Instructions Manual page 18

Note:
Provide a drain & fill valve at the lowest point in the system.
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 corro-
sion.
- 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
- Install a strainer/dirt trap in the return line and service the
strainer/dirt trap at regular intervals, see WOLF accessories
(500μm = 0.5mm)
- The automatic air vent valve for the appliance must be
opened during operation
- The max. flow rate of 100 l/min (6000 l/h) must not be ex-
ceeded
- Drinking water or desalinated domestic drinking water should
be used as fill water and top-up water The hardness of the
system water must be less than 2 dH. The fill and top-up
water qualities for the specific system can be found in the
chapter "Technical information for water treatment".
- If an ingress of oxygen cannot be ruled out, a system sep-
aration is advisable
- The heating water pH value must be between 8.2 and 8.5
- In general, fill and top-up water must be desalinated; soften-
ing by means of a single stage de-ioniser is not permissible.
For this, the permissible methods and limits should be
obtained from the chapter "Technical information for water
treatment" (NOTE the limit values are specific to the system).
- Inhibitors and antifreeze are not permissible.
- A system log must be kept (see Technical information for
water treatment)
After correct filling of the system, the system must be heated up
to the maximum level and then the total hardness and pH value
must be measured again and adjusted as necessary. These
values must be checked and adjusted again after 6-8 weeks.
18
10. Installation
Additional requirements for operation without a low loss
header
- Systems with only one CGB-75/100
- Sludge separator in the boiler return of the CGB-75/100
- Desalination of the heating water to 2 - 3 °dH
- Control of cylinder charging only via the MM module (con-
- Cylinder charging 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 heat-
ing water. In the event of oxygen penetrating the system, we
recommend a system separation through the interconnection
of a heat exchanger.
Information from VDI 2035
The way in which commissioning in particular is carried out
can have a strong influence on scaling. Heat the system at the
lowest output with an even and adequate throughput. For mul-
ti-boiler systems it is recommended to commission all boilers
simultaneously to prevent the overall amount of lime concen-
trating on the heat exchanger surface of an individual boiler.
For a specific system volume of >50 l/kW, adjust the total
hardness to 2-3°dH using a desalination process.
figurations 1 and 10)
head
HG08 to 75 °C
The technical information for water treatment
must be observed, otherwise system damage
due to water leaks may occur.
carry out a leak test on the piping:
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 (100 l/min).
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