Wolf FGB-K Series Installation And Maintenance Instructions For Contractors page 14

FGB ... wall mounted gas condensing boiler
Gas condensing boiler, with electronic ignition and electronic
flue gas temperature monitoring, for low temperature heating
and DHW heating in heating systems with flow temperatures
up to 90 °C and 2.5 bar permissible operating pressure to
DIN EN 12828. This Wolf gas condensing boiler is also
approved for installation in garages.
Gas condensing boilers operated with an open
flue may only be installed in rooms that comply
with the appropriate ventilation requirements.
Otherwise there is a risk of asphyxiation
or poisoning. Read the installation and
maintenance instructions before installing
the boiler. Also take into consideration all
technical information.
When operating the boiler with LPG use only
propane according to DIN 51 622, otherwise
faults may arise when starting and operating
the gas condensing boiler, which may lead to
injury and material losses.
A poorly vented LPG tank can lead to problems
with ignition. In such a case, contact the
company that fills the LPG tank.
The adjustable cylinder water temperature
can exceed 60 °C. Short-term operation at
temperatures above 60 °C must be monitored
in order to prevent scalding. For permanent
operation, appropriate precautions should be
taken to prevent draw-off temperatures above
60 °C, e.g. thermostatic valve.
To protect against scaling, the DHW temperature should
be set to max. 50 °C when the total water hardness is
15 °dH (2.5 mol/m³) or above.
In accordance with the Drinking Water Ordinance
[Germany], this is the lowest permissible value for
DHW temperatures, as it practically rules out the risk
of legionella proliferation with daily use of the hot
water system. (When installing a DHW cylinder ≤ 400
l; complete exchange of water in the cylinder through
usage within 3 days.)
With a total hardness of 20 °dH or higher, the use of a
water treatment facility in the cold water supply line
when heating DHW is essential, in order to extend the
maintenance intervals.
Even if water hardness is below 20 °dH, a higher risk of
scale build-up may occur locally, necessitating suitable
softening measures. Failure to take such measures will
result in premature scaling of the appliance and reduced
DHW convenience. The contractor should always check
the local conditions.
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6. Standards and regulations
Fig: Wolf wall-mounted gas condensing boiler
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