Pre-Installation; Cleaning Primary Systems; Before Cleaning The System; Flushing The System - Bosch WORCESTER Greenstar Danesmoor 18/25 Installation, Commissioning And Servicing Instruction Manual

Pre-Installation

4 Pre-Installation
4.1

Cleaning primary systems

DANGER: Danger to life through electric shock!
▶ Before carrying out any work on electrical
components, isolate them from the power supply
(230 V AC) (fuse, circuit breaker) and secure against
unintentional reconnection.
NOTICE: Risk of damage to appliance or accessories!
▶ All the following pre-installation sections must be
read and requirements met before starting the
appliance or flue installations.
NOTICE: Risk of damage to system or appliance!
Debris from the system can damage the appliance and
reduce efficiency. Failure to comply with the guidelines
for the use of water treatment with the appliance will
invalidate the appliance guarantee and contravene the
Building Regulations.
▶ It is a requirement of the Building Services
Compliance Guide which is a second tier document
to the Building Regulations to flush and inhibit the
primary water system in accordance with BS 7593.
▶ It is recommended that you fit a primary water
cleanser to the system. Worcester recommends
fitting a filter that will help remove both magnetite
and non-magnetic debris.
4.1.1

Before cleaning the system:

▶ Ensure that the system and pipe work is in good working order.
▶ Where possible keep the existing appliance/circulating pump in
place when flushing the system.
Follow the guidance of BS7593:
Treatment of water in domestic hot water central heating and also the
flushing guidelines below.
4.1.2

Flushing the system

▶ Fill the system with cold water and check for leaks.
▶ Open vented systems only:
– Turn off the water to the system header tank.
▶ Open all drain cocks and drain the system.
– See figure 5 for appliance drain points.
▶ Close drain cocks and add a suitable flushing agent at the correct
strength for the system conditions in accordance with the
manufacturer's instructions.
▶ Circulate the flushing agent before the boiler is fired up.
▶ Run the boiler/system at normal operating temperature as directed
by the manufacturer of the flushing agent.
▶ Drain and thoroughly flush the system to remove the flushing agent
and debris.
▶ It may be necessary to use a power flushing machine to aid the
cleansing procedure in some circumstances.
▶ Close the drain cocks and manual air vents.
▶ Add a suitable inhibitor to the system in accordance with the
manufacturers instructions.
▶ Open vented systems only:
– Turn on the water to the system header tank and allow the system
to fill.
▶ Sealed systems only:
– Fill the system to between 1 and 1.5 bar via a WRAS approved
filling loop.
▶ Vent any air from the boiler and system.
– See figure 6 for appliance manual vent points.
12
4.1.3

Appliance drain points

▶ The appliance can be drained via the primary heat exchanger point
[3]:
– There is an additional drain point on the secondary heat
exchanger [1].
Fig. 5 Appliance drain points
[1] Secondary heat exchanger drain point.
[2] Secondary heat exchanger drain hose.
[3] Primary heat exchanger drain point.
4.1.4

Appliance vent points

There are two vent points at the top of the secondary heat exchanger.
Only one may be in use, the other may be obscured by side fluing.
▶ Use a radiator key or suitable screwdriver to open the vent point.
Fig. 6 Manual vent points
[1] Manual vent points (each side of the secondary heat exchanger).
4.1.5

Inhibitor

Add a suitable inhibitor or combined inhibitor/anti-freeze, if the system
is exposed to freezing conditions, to the heating system in accordance
with the DWTA code of practice and manufacturer's guidelines.
The inhibitor or combined inhibitor/anti-freeze must not
cause damage to the materials within the boiler (mild
steel, stainless steel, copper and brass) and any other
materials/components within the system.
▶ The concentration level of inhibitor in the system
should be checked every 12 months or sooner if
system content is lost.
WARNING: Sealing agents
▶ In cases where all attempts to find a system micro
leak have failed, Worcester, Bosch Group supports
the use of Fernox F4 leak sealer.
Greenstar Danesmoor Kitchen ErP+ and Kitchen System
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ErP+ -6 720 821 686 (2018/04)
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