Hydraulic Wiring In The System; Filling And Purging The System; Filling And Purging The Heating Circuit - Vaillant flexoTHERM exclusive VWF 57/4 Installation And Maintenance Instructions Manual

7 Filling and purging the system

6.4

Hydraulic wiring in the system

6.4.1 Installing heating circuits with direct
connection
1. Install the hydraulic components in accordance with
the local requirements as shown in the system diagram
example, → Installation instructions for the system.
2. Connect the underfloor heating circuits or heating circuit
distributors directly to the heat pump.
3. Connect a limit thermostat to ensure that the heat
pump's underfloor protection works correctly.
(→ Page 22)
4. Ensure that a minimum volume of circulating water is
guaranteed.
–
Minimum volume of circulating water: 35% of the
nominal flow
6.4.2 Installing heating circuits with direct
connection and domestic hot water cylinder
1. Install the heating circuits for direct operation.
(→ Page 18)
2. Secure the temperature sensor (VR10), available from
the range of accessories, in the domestic hot water
cylinder and connect it to the heat pump.
7 Filling and purging the system
7.1

Filling and purging the heating circuit

7.1.1 Checking and treating the heating
water/filling and supplementary water
Caution.
Risk of material damage due to poor-qual-
ity heating water
▶
Ensure that the heating water is of suffi-
cient quality.
▶
Before filling or topping up the system, check the quality
of the heating water.
Checking the quality of the heating water
▶
Remove a little water from the heating circuit.
▶
Check the appearance of the heating water.
▶
If you ascertain that it contains sedimentary materials,
you must desludge the system.
▶
Use a magnetic rod to check whether it contains mag-
netite (iron oxide).
▶
If you ascertain that it contains magnetite, clean the sys-
tem and apply suitable corrosion-protection measures, or
fit a magnet filter.
▶
Check the pH value of the removed water at 25 °C.
▶
If the value is below 8.2 or above 10.0, clean the system
and treat the heating water.
▶
Ensure that oxygen cannot get into the heating water.
Checking the filling and supplementary water
▶
Before filling the system, measure the hardness of the
filling and supplementary water.
18
Treating the filling and supplementary water
▶
Observe all applicable national regulations and technical
standards when treating the filling and supplementary
water.
Provided the national regulations and technical standards
do not stipulate more stringent requirements, the following
applies:
You must treat the heating water in the following cases:
–
If the entire filling and supplementary water quantity dur-
ing the operating life of the system exceeds three times
the nominal volume of the heating installation, or
–
If the guideline values listed in the following table are not
met, or
–
If the pH value of the heating water is less than 8.2 or
more than 10.0.
Applicability: Great Britain
Total
Water hardness at specific system volume
heating
output
≤ 20 l/kW
ppm
kW
CaCO₃
< 50 < 300
> 50 200
to ≤ 200
> 200 150
to ≤ 600
> 600 2
1) Nominal capacity in litres/heating output; in the case of multi-
boiler systems, the smallest single heating output is to be used.
Applicability: Great Britain
Caution.
Risk of material damage if the heating
water is treated with unsuitable additives.
Unsuitable additives may cause changes in
the components, noises in heating mode and
possibly subsequent damage.
▶
Do not use any unsuitable frost and cor-
rosion protection agents, biocides or seal-
ants.
No incompatibility with our products has been detected to
date with proper use of the following additives.
▶
When using additives, follow the manufacturer's instruc-
tions without exception.
We accept no liability for the compatibility of any additive or
its effectiveness in the rest of the heating system.
Additives for cleaning measures (subsequent
flushing required)
–
Fernox F3
–
Sentinel X 300
–
Sentinel X 400
Additives intended to remain permanently in the
system
–
Fernox F1
Installation and maintenance instructions flexoTHERM exclusive 0020213395_00
> 20 l/kW
≤ 50 l/kW
mol/ ppm mol/ ppm
m³ CaCO₃ m³ CaCO₃
< 3 200 2 2
2 150 1.5 2
1.5 2 0.02 2
0.02 2 0.02 2
1)
> 50 l/kW
mol/
m³
0.02
0.02
0.02
0.02