Installing A Pressure-Relief Valve; Temperature Sensor; Immersion Heater (Accessory); Commissioning - Buderus Logalux SM310.5 E Installation And Service Instructions Manual

6

Commissioning

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. 11, 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. 50).
▶ Attach a notice with the following text to the pressure relief valve:
"Never close the discharge pipe. During heating, water may be
discharged for operational reasons."
If the static system pressure exceeds 80 % of the pressure relief valve
excess pressure:
▶ Install a pressure reducer upstream ( Fig. 11, 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 52 Selection of a suitable pressure reducer
5.4

Temperature sensor

Mount a temperature sensor for measuring and monitoring the water
temperature. Number and position of the temperature sensor (sensor
pocket), see process description, Tab. 48.
▶ Fit the temperature sensor ( Fig. 12, page 71).
To ensure good thermal contact, ensure that the sensor surface has
contact with the sensor pocket surface over its full length.
5.5

Immersion heater (accessory)

▶ Install the immersion heater in accordance with the separate
installation instructions.
▶ Once the cylinder is fully installed, inspect the protective conductor.
This should also include the metal connection fittings.
46
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!
Positive pressure can result in stress cracks in the glass lining.
▶ 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:
purge the pipework and cylinder with potable water.
▶ Fill the cylinder whilst a DHW draw-off point is fully open,
until water flows steadily from it.
▶ Carry out tightness test.
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. 53).
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. 53).
– 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.
Logalux – 6721829955 (2020/12)