Essential Elements In A Dhw System; Dhw System Piping - Bosch Singular 4000 Installation Instructions Manual

Installation Instructions
Bosch is not responsible for the blockage of the domestic system due to the
accumulation of foreign matters or scaling.
The installer or the user should take appropriate measures in order to avoid any
problem related to the quality of water.
Freeze Protection
Bosch recommends insulating the DHW pipes. The pipes can be covered using
heat-insulating materials. Freeze damage voids the warranty.

4.2.2 Essential Elements in a DHW System

Drain and Isolation Valves
Install drain and isolation valves on the inlet and outlet of the DHW heat exchanger,
so it can be fl ushed free of possible build-up caused by dirt or hard water.
DHW Filter
Singular boiler has a fi lter on its cold water inlet nipple. Clean the fi lter periodically
to prevent the interruption of water fl ow by foreign matters.
If such foreign substances adhere to the fl ow switch, the boiler may malfunction.
Pressure Relief Valve for DHW
To complete the installation of the DHW system, you must install the approved ¾",
maximum 150psi pressure relief valve on the hot water outlet.
The DHW pressure relief valve is not provided together with the product. However,
it is necessary to install such a valve.
WARNING: PERSONAL INJURY, PROPERTY DAMAGE
 Improper installation of the pressure relief valve may result
in property damage, personal injury, or death.
 Follow all instructions and guidelines when installing the
pressure relief valve. Only a licensed professional should
install the valve.
CAUTION: PERSONAL INJURY, PROPERTY DAMAGE
 Install the pressure relief valve as close to the boiler as
possible. No valve should be installed between the pressure
relief valve and the boiler.
When installing the pressure relief valve, follow the guidelines below.
 The discharge capacity of the valve should be greater than or equal to the
maximum pressure rating of the DHW system in the boiler.
 The maximum Btu/h rating of the pressure relief valve should be greater
than or equal to the maximum input Btu/h rating of the boiler.
 If the pressure relief valve operates, discharging domestic hot water may
scatter or splash onto other equipment around. Connect the pressure
relief valve to the DHW outlet pipe.
 When installing the discharge piping line, do not install a coupling whose
internal diameter decreases or has other restrictions.
If the pressure relief valve discharges hot water periodically, it may be caused by
thermal expansion of the closed water system. The suggested method of controlling
thermal expansion is to install an expansion tank in the cold water line between
the boiler and the check valve. Contact the water supplier or a local plumbing
contractor. Do not plug the pressure relief valve.
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4.2.3 DHW System Piping

CAUTION: PERSONAL INJURY, PROPERTY DAMAGE
 In order to meet the requirements of ASME or CRN, an
additional high temperature limitation device may be
required. Refer to the requirements of the local code for
whether this device is required.
Figure 12
When installing the DHW system, follow the guidelines below.
 Only use permitted pipes, valves and other parts such as a solder for the
potable water system.
 Tighten the connection valves carefully in order to avoid damage.
 Bosch recommends the use of unions and manual shut-off valves for the
cold water inlet and DHW outlet.
 Keep the hot water piping system as short as possible, to deliver hot water
to the fixtures more quickly.
 When installing a mixing valve on the DHW piping, ensure that the cold
water pressure does not exceed the hot water pressure.
 To conserve water and energy, insulate the DHW supply and DHW
recirculation lines (if applicable). Do not cover the drains or pressure relief
valves.
 After installing the boiler, clean the cold water inlet filter. Then, check
if domestic water flows properly and check for water leaks. Inform
boiler owner that the filter should be cleaned periodically to ensure that
domestic hot water flows smoothly.
Singular Combi Boiler - BTC 439003301 B (2021/07)
Cold
DHW
water
supply
supply