Filling The Heating System; Preparing The Heating System For Operation; Commissioning The Control Unit And Burner; Setting Control Unit Parameters - Bosch Buderus SB625WS Installation Instructions Manual

32 | Commissioning
6.7

Filling the heating system

NOTICE: System damage through temperature
stresses.
▶ Only fill the heating system when cold (the flow
temperature must not exceed 104 °F (40 °C)).
▶ During operation, only fill the heating system via the
fill valve in the heating system pipework (return).
CAUTION: Health risk through contaminated drinking
water.
▶ Observe all country-specific regulations and
standards regarding the prevention of drinking water
contamination.
Open the automatic air vent valve only briefly for venting.
The fill and top-up water quality must comply with the water
requirements in this manual.
The pH value of the heating water increases after the heating system has
been filled. After 3 – 6 months (initial service) check whether the pH
value of the heating water has settled down.
▶ Adjust the pre-charge pressure of the expansion vessel to the
required pressure (only for sealed unvented systems).
▶ Open the shut-off valves on the heating water side.
▶ Fill the heating system slowly and observe the pressure gauge whilst
doing so.
▶ Vent the heating system via the radiator air vent valves.
If the water pressure drops as a result of venting the system:
▶ Top up the system with water.
▶ Carry out a leak test in accordance with locally applicable regulations.
▶ After the tightness test, reinstate all components that were taken out
of operation.
▶ Ensure that all pressure, control and safety equipment is functioning
correctly.
Once the boiler has been tested for tightness and no leaks have been
found:
▶ Set the correct operating pressure. The working pressure in the
heating system should be over 14 PSI but below the maximum limit
specified for the boiler.
▶ Close the automatic air vent valve.
6 720 805 218 (2013/02)
6.8

Preparing the heating system for operation

Observe the following points during commissioning:
▶ The turbulators [2] are correctly positioned (horizontal) inside the
heat exchanger tubes and the clips [1] are resting against the wall [3]
of the heat exchanger.
1
Fig. 31 Heat exchanger tube
[1] Clip
[2] Turbulator
[3] Wall
▶ Before commissioning, vent the heating system via the ventilation
facilities provided for this purpose.
▶ Check that the inspection aperture on the flue gas collector is closed.
▶ Check that the combustion chamber door is securely closed.
▶ Check that the safety equipment (e.g. safety valve, minimum and
maximum pressure limiters, high limit safety cut-out) is functioning
correctly.
▶ Check that the required operating pressure has been achieved.
▶ Check the flange connections and other connections for tightness.
▶ Check the control unit connections and temperature sensor
positions.
▶ Fill the condensate siphon.
6.9

Commissioning the control unit and burner

By commissioning the control unit you automatically commission the
burner as well. The burner can then be started by the control unit. For
further information, see the installation instructions of the relevant
control unit or burner.
▶ Use the control unit to commission the boiler.
▶ Set the control unit parameters ( chapter 6.10, page 32).
▶ Complete the commissioning report in the technical documentation
of the burner.

6.10 Setting control unit parameters

The controller settings listed in table 14 apply to the Logamatic 4321
control unit.
For further information on setting the control unit, see chapter 6.1,
page 28.
Burner
Burner type for fuel
Burner Gas
Modulating
2-stage
Single fuel
burner
Table 14 Controller settings for Logamatic 4321 control unit
2
3
6 720 805 218-33.1T
Control unit setting
Burner type
to be Fuel to be
selected selected
Modulating Gas
2-stage Gas
SB625WS/SB745WS