Establishing The Hydraulic Connection To The Cylinder; Installing A Pressure-Relief Valve; Temperature Sensor; Commissioning - Bosch Stora SWDP 200-2 Installation And Service Instructions Manual

5.3.1

Establishing the hydraulic connection to the cylinder

System schematics with all recommended valves in the graphic part
( Fig. 13, page 70)
▶ Use installation material that is temperature-resistant up to 95 °C
(203 °F).
▶ Never use open, vented expansion vessels.
▶ Use metal connection fittings in DHW heating systems with plastic
lines.
▶ Size the drain line in accordance with the connection.
▶ To facilitate debris removal, never install elbows in the drain line.
▶ Keep heat input as short as possible and insulate it.
▶ If using a non-return valve in the cold water supply: Install a pressure
relief valve between the non-return valve and cold water inlet.
▶ Install a pressure reducer in the cold water pipe if the static pressure
in the system is in excess of 5 bar.
▶ Seal all unused connections.
▶ Press the heating coil connections and connect the water
connections with flat sealed joint.
5.3.2

Installing a pressure-relief valve

▶ Install a pressure-relief valve that is approved for potable water
(≥ DN 20) in the cold water supply ( Fig. 13, page 70).
▶ Observe the pressure relief valve installation instructions.
▶ Terminate the discharge pipe where it will be easily visible in the
frost-proof area via a dewatering point.
– The discharge pipe must be at least equal to the outlet cross-
section of the pressure relief valve.
– The discharge pipe must be able to discharge at least the
volumetric flow rate that could possibly arise at the cold water
inlet ( Tab. 29).
If the static system pressure exceeds 80% of the pressure relief valve
excess pressure:
▶ Install a pressure reducer upstream ( Fig. 13, page 70).
Gas supply Pressure relief
pressure valve excess
(static pressure) pressure
< 4.8 bar ≥ 6 bar
5 bar 6 bar
5 bar ≥ 8 bar
6 bar ≥ 8 bar
7.8 bar 10 bar
Table 30 Selection of a suitable pressure reducer
5.4

Temperature sensor

CAUTION
The sensors are not included in the scope of delivery and must be
ordered separately.
▶ For further information, please refer to the technical documentation
of the heat pump.
Connect a temperature sensor for measuring and monitoring the DHW
temperature.
▶ Number of temperature sensors, see product description, Tab. 27,
page 24.
▶ Locations of the temperature sensors (Fig. 4, page 66).
▶ The sensor must not be connected to 230 V.
Stora – 6721847474 (2023/02)
Pressure reducer
In the EU + Outside the
CH EU
Not Not
required required
≤ 4.8 bar ≤ 4.8 bar
Not Not
required required
≤ 5 bar Not
required
≤ 5 bar Not
required
6

Commissioning

DANGER
Danger of cylinder damage through positive pressure!
stress cracks may result from excessive pressure.
▶ Never close the discharge pipe of the pressure relief valve.
▶ Before connecting the cylinder, carry out a tightness test on the water
lines.
▶ Commission the wall mounted boiler, assemblies and accessories
according to the
manufacturer's notices and the technical documentation.
6.1

Commissioning the cylinder

▶ Before filling the cylinder:
flush the pipework and cylinder with potable water.
( Fig. 14, page 71)
▶ Fill the cylinder whilst a DHW draw-off point is fully open, until water
flows steadily from it. ( Fig. 15, page 71)
▶ Carry out tightness test. ( Fig. 16, page 71)
Only perform the tightness test of the cylinder using potable water. On
the DHW side, the test pressure must not exceed 10 bar positive
pressure.
Setting the cylinder temperature
▶ Set the required cylinder temperature in accordance with the
operating instructions of the wall mounted boiler, taking the risk of
scalding at the DHW draw-off points into consideration
( Chapter 6.2).
6.2

Instructions for the user

WARNING
Risk of scalding at the DHW draw-off points!
Depending on the system and operating conditions (thermal
disinfection) there is a risk of scalding at the DHW draw-off points in
DHW mode.
Installation of a thermal mixer is prescribed when setting a DHW
temperature via 60 °C.
▶ Advise users that they should draw off only mixed water.
▶ Explain the operation and handling of the heating system and
cylinder, making a particular point of safety-relevant features.
▶ Explain the function and how to check the pressure relief valve.
▶ Hand all enclosed documents over to the user.
▶ Recommendation for the operator: Conclude a maintenance and
inspection contract with an approved contractor. Have the cylinder
serviced and inspected annually at the specified maintenance
intervals ( Tab. 31).
Highlight the following for the user:
▶ Setting the DHW temperature.
– Water may be discharged from the pressure relief valve when
heating-up.
– Always keep discharge pipe for pressure-relief valve open.
– Comply with maintenance intervals ( Tab. 31).
– Where there is a risk of frost and when the operator is briefly
away: Keep the heating system in operation and set the lowest
possible DHW temperature.
Commissioning
27