Ochsner AIR BASIC 109, Operating Manual/Installation Manual

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BA_AIR_BASIC_ELW_Multitower_OTE3_SW5x_CC_EN_V08.docx Page 20 of 92
4.1.6 System pressure/heating water
Preparation for filling:
A 24 l expansion vessel is installed in the heat
pump indoor unit. In buffer systems or systems
with higher capacity, check this vessel and, if
necessary, install an additional expansion vessel in
the system (externally, not inside the appliance).
Before filling the system, check the pre-charge
pressure in the expansion vessel. This must be
matched to the building height.
Static head: Difference between highest and
lowest points in the system
Pre-charge pressure = static head + 0.3 bar
System charge pressure = pre-charge pressure
+0.5 bar (when cold)
Max. permissible operating pressure: 3.0 bar
(safety valve)
•
Flush the heating system thoroughly
before filling.
•
Only fill with water of potable quality.
•
Fill water harder than 16.8 °dH (3.0
mol/m³) must be softened.
Unsuitable fill- and top-up water promotes
deposits and rust formation and can damage the
system. With regard to the quality and quantity of
heating water, including filling and top-up water,
observe VDI 2035 or ÖNORM H5195-1 and 2.
Figure 24: Detailed view of indoor unit drain & fill valve
NOTE
Drain and fill
opening