Regulations; General; Standards And Guidelines; Inspection And Maintenance - Bosch Worcester Greenstar HIU E Installation And Maintenance Instructions Manual

3

Regulations

3.1

General

The special rules must be followed for buildings where the appliance is
installed.
The installation and maintenance of the unit must be performed by a
qualified person in accordance with regulations and rules of the local
area where installation is to take place.
3.2

Standards and Guidelines

Observe all rules, regulation, standard and guidelines
applicable to the installation and operation of the
appliance in your country.
When installing and operating, please refer to country-specific
regulations and standards, note in particular:
▶ The local standards and regulations on the installation conditions.
▶ The provision for the electrical connection to the power supply.
▶ The standards and regulations relating to the safety equipment of the
water heating system.
▶ The standards and regulations relating to the connection of drinking
water.
3.3

Inspection and maintenance

The heating system should be inspected regularly for the following
reasons:
• To achieve and maintain a high efficiency.
• To ensure operational safety.
The recommendation from BSRIA BG62/2015 is a maintenance check
every 3 years should be sufficient.
NOTICE: Risk of system damage!
Damage to the system caused by a lack of, or insufficient
cleaning and servicing.
▶ Ensure that the heating system is inspected regularly
by an authorised heating engineer.
▶ Carry out any repairs immediately to avoid any
damage to the system.
4

Pre-installation requirements

4.1 General
NOTICE: Differential pressures above 80kPa
(800mbar) when no internal DPCV is fitted.
High differential pressure could affect the performance
of some components in the unit.
▶ Fit a differential pressure control valve to protect the
unit.
▶ The maximum allowable supply differential pressure
when the internal differential pressure control valve
is fitted is 400kPa (4000mbar).
It is recommended to insulate all service pipe work to the
heat interface unit in order to reduce heat losses and
improve system efficiency.
6 720 808 928 (2017/06)
4.2

System preparation

Water system and pipe-work
• Any plastic pipe-work used on the central heating system must have
a polymeric oxygen barrier coating and at least 1000mm length of
copper or steel pipe connected to the appliance.
• Plastic pipe-work used for under-floor heating must be correctly
controlled and must not exceed the under-floor manufacturers'
specifications.
– With a single under-floor heating zone this may be able to be
controlled by the HIU provided the under-floor heating design
does not exceed the hydraulic capacity of the HIU internal
circulating pump, refer to section 6.6, Central heating circulation
pump.
• The district circuit is completely separated from the central heating
circuit by the use of a plate heat exchanger. However, in order to
protect the under-floor circuit in the event of a failure condition, a
limiter thermostat must be fitted onto the flow pipe to the under-floor
circuit and wired into the control unit ( figure 6). This switches off
the central heating pump in the event of an over temperature
condition.
• A single under-floor heating circuit can be controlled without the
need for an external mixing valve.
The switching point of the limiter thermostat, and if
fitted a thermostatic blending valve must be set at the
temperature set point + 10K for the under-floor heating
circuit.
The minimum flow temperature of the appliance is 30 °C.
NOTICE: Under-floor heating circuits.
Damage caused by excessive flow temperature.
▶ Ensure the flow temperature does not exceed the
requirements of the under-floor heating circuit
manufacturer.
Secondary circuit/connections/valves
• All system connections, taps and mixing valves must be capable of
sustaining a pressure of 3 bar.
• Radiator valves should conform to local regulations.
• A thermostatic radiator valve (TRV) must be fitted to radiators in all
rooms except the room with the room thermostat. This must be fitted
with lock-shield valves and left open.
• Drain cocks are required at all the lowest points on the system.
• Air vents are required at all high points on the system.
Regulations
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