Regulations; Water Quality - Bosch Compress 7400i AW Installer's Manual

H Installation, commissioning and service
The heat pump may only be installed, brought into
operation and maintained by authorised personnel.
▶ Use only original spare parts.
H Electrical work
Electrical work may only be performed by authorised
electrical installers.
Before commencing work:
▶ Disconnect mains voltage on all poles and ensure it
cannot reconnect.
▶ Check to ensure that the power is disconnected.
▶ Also check the connection diagram for other parts
of the system.
H Handover to the user
When handing over, instruct the user how to operate
the heating system and inform the user about its
operating conditions.
▶ Explain how to operate the heating system and draw
the user's attention to any safety relevant action.
▶ In particular, point out the following:
– Modifications and repairs must only be carried
out by an approved contractor.
– Safe and environmentally compatible operation
requires inspection at least once a year and
proper cleaning and maintenance.
▶ Point out the possible consequences (personal
injury, including danger to life or material damage)
of non-existent or improper inspection, cleaning
and maintenance.
▶ Leave the installation instructions and the
operating instructions with the user for
safekeeping.
2

Regulations

This is an original manual. This manual may not be translated without the
approval of the manufacturer.
Follow the directives and regulations given below:
• Local provisions and regulations of the electricity supplier and
corresponding special rules
• National building regulations
• F-Gas regulation
• EN 50160 (Voltage characteristics of electricity supplied by public
electricity networks)
• EN 12828 (Heating systems in buildings - Design for water-based
heating systems)
• EN 1717 (Protection against pollution of potable water installations
and general requirements of devices to prevent pollution by
backflow)
• EN 378 (Refrigerating systems and heat pumps - Safety and
environmental requirements)
Compress 7400i AW – 6721833372 (2021/09)
2.1

Water quality

Water quality in the heating system
Heat pumps operate at lower temperatures than other heating systems
which means that the thermal de-airing is not as effective and oxygen
levels are never as low as with a system incorporating an electric/oil/ gas
boiler. This means that the heating system will be more susceptible to
corrosion when exposed to aggressive water.
Preventive actions are required if the heating systems require recurrent
filling or where a heating water sample does not show clear water.
Preventive actions can be to supplement the heating system with a
magnetite filter and a de-airing valve.
Actions when the heating system requires recurrent filling:
▶ Check that the volume of the expansion vessel is sufficient for the
heating system volume.
▶ Replace the expansion vessel.
▶ Check the heating system for leakages.
A system separation with the help of a heat exchanger may be required if
the limits in table 2 can not be achieved.
The limits stated in table 2 are required to ensure the output data and
operation of the heat pump throughout its entire life span.
Water quality
Hardness
Oxygen content
Carbon dioxide, CO
2
-
Chloride ions, CL
Sulphate, SO
4
Conductivity
pH
Table 2 Water quality
Additional water treatment to prevent lime-scale deposits
Poor quality of the heating water promotes the formation of sludge and
lime-scale. This can lead to malfunctions and damage of the heat
exchanger in the heat pump. According to the current guideline VDI
2035 "Avoidance of Damage in hot water heating systems" and
depending on the degree of hardness of the filling water, the system
volume and the total output of the system, water treatment may be
required to avoid damage due to the formation of lime-scale.
NOTICE
Risk of damage to system or appliance!
Debris from the system can damage the appliance and reduce efficiency.
▶ Follow the guidance of BS7593 for treatment of water in domestic
1)
hot water heating systems .
▶ Do not use anti-freeze/glycol products.
Suitable water treatment products (inhibitors/cleaners) can be
obtained from the following manufacturers:
ADEY 01242 546700
www.adey.com
FERNOX 0330 100 7750
www.fernox.com
SENTINEL 01928 704330
www.sentinelprotects.com/uk
Table 3
1) Only applicable in the United Kindgom.
Regulations
<3 °dH
<1 mg/l
<1 mg/l
<250 mg/l
<100 mg/l
<350 μS/cm
7,5 – 9
3