Filling The Condensate Trap; System Filling; Built-In Water Filling; External Water Fill Connection - Bosch Singular 4000 Installation Instructions Manual

Installation Instructions
2. Place the free end of the drain line into an appropriate drain.
NOTICE:
 If you are using a condensate pump, ensure that the pump
allows for up to 2 GPH of drainage for each boiler in the
system.
 If you are not using a condensate pump, ensure that the
drain line is pitched downward at a minimum slope of 1/4"
per foot.

4.3.1 Filling the Condensate Trap

Before operating the boiler, fi ll the condensate trap with water through the fl ue
connector. The boiler may be severely damaged unless fi lled with water prior to
operation. Pour more than 0.1 gallon (400 ml) of water into the exhaust duct. Open
air vent cap suffi ciently or equip the air vent with an outlet pipe prior to fi lling the
condensate trap with water (there must be no air inside the heat exchanger).
Figure 15
2 0 |

4.4 System Filling

4.4.1 Built-In Water Filling

The boiler is designed to fi ll the system with water. Therefore, additional water fi ll
connection is not necessary in most cases. Filling the system with water should be
carried out after all space heating pipes and DHW pipes are connected.
The procedure is as follows.
 When you turn the makeup water feeding valve shown in the figure below
counterclockwise, the space heating system will be filed with water.
 When filling with water after installing it for the first time, it may operate
and stop repeatedly due to the presence of air. Allow sufficient time to
remove air from the pipes completely.
 After filling with water completely and removing air completely, close the
makeup water feeding valve by turning it clockwise.
 Fill the system with water to a level at which the pressure inside the
system does not exceed 30psi.
Figure 16

4.4.2 External Water Fill Connection

External water fi ll connection may be installed on the system piping if it is required
for specifi c applications. See the following fi gure for an example of external water
fi ll installation on the system piping.
To System
Circulator
Air Separator
Make-up water
Expansion Tank
Figure 17
Singular Combi Boiler - BTC 439003301 B (2021/07)
From
System