13
The individual protection reduces the frequency and
level of pressure fluctuations. This significantly increa-
ses the operational reliability and service life of the
system components. Failure to observe these recom-
mendations may result in damage to the boiler or to
other system components.
Only use pump controlled pressure maintaining sys-
tems that are sealed to prevent corrosion. The pres-
sure maintaining systems must be protected against
oxygen ingress into the heating water. Otherwise dam-
age to the system through oxygen corrosion can result.
Pump controlled pressure maintaining systems with
atmospheric deaeration through cyclical pressure
release effect a central post-ventilation of the heating
system. They do not provide oxygen removal in the
sense of corrosion protection as described in VDI 2035
Part 2.
Note
Check the pressure maintaining system in line with the
manufacturer's instructions.
!
Please note
Cyclical pressure fluctuations and more signifi-
cant pressure differentials point towards a sys-
tem fault. Such faults result in damage to other
heating system components.
Limit pressure fluctuations to the lowest possible
differential.
Checking the firm seating of electrical plug-in connections and cable
grommets
Checking the thermal insulation
Checking the water quality
Observe the instructions in chapter "Water quality
requirements" in the appendix.
Enter the amount of top-up water and the total hard-
ness of the feed and boiler water into the table on
page 31.
The total hardness of the feed and top-up water must
not exceed 0.11 °dH (total value of alkaline earths
≤
0.02 mol/m
3
).
The pH value should be between 9 and 10.5.
Commissioning, inspection, maintenance
Checking the expansion vessel and system…
(cont.)
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