PAW FriwaMidi DN 20 User manual

PAW GmbH & Co.KG
Böcklerstr. 11, 31789 Hameln - Germany
Phone: [phone], Fax: [phone]
E-mail: [email protected], Web: www.paw.eu
2020/06 99640x5xx-mub-en – V01 1
Installation and Operation Instructions
Domestic hot water modules
FriwaMidi – DN 20
FriwaMaxi – DN 25

1General Information
2 99640x5xx-mub-en – V01 2020/06
Item no. 99640x5xx-mub-en - Version V01 - Issued 2020/06
Translation of the original instructions
We reserve the right to make technical changes without notice!
Printed in Germany – Copyright by PAW GmbH & Co. KG
PAW GmbH & Co.KG
Böcklerstraße 11
31789 Hameln
Germany

1General Information
2020/06 99640x5xx-mub-en – V01 3
Contents
1General Information.........................................................................................................4
1.1 Scope of these instructions ..........................................................................................4
1.2 About this product ........................................................................................................5
1.3 Designated use ............................................................................................................5
2Safety instructions ...........................................................................................................6
3Product description..........................................................................................................8
4Dimensioning and planning..............................................................................................9
4.1 Dimensioning of the tank............................................................................................10
4.2 Water quality requirements.........................................................................................11
5Circulation mode ...........................................................................................................13
6Mounting and installation [specialist] ..............................................................................14
7Commissioning [specialist].............................................................................................17
7.1 Filling the primary circuit.............................................................................................18
7.2 Commissioning of the controller ................................................................................. 19
7.3 Maximum withdrawal flow rate ...................................................................................21
7.4 Adjustment of the temperature ................................................................................... 23
8Maintenance .................................................................................................................25
9Disposal........................................................................................................................26
10 Spare parts [specialist] ..................................................................................................27
10.1 Spare parts control and insulation
FriwaMidi without circulation (6405510 + 6405530) / with circulation (6405515 + 6405535).. 27
10.2 Spare parts hydraulics
FriwaMidi without circulation (6405510 + 6405530) / with circulation (6405515 + 6405535).. 28
10.3 Spare parts control and insulation
FriwaMaxi without circulation (6406510 + 6406530) / with circulation (6406515 + 6406535). 29
10.4 Spare parts hydraulics
FriwaMaxi without circulation (6406510 + 6406530) / with circulation (6406515 + 6406535) 30
11 Technical data...............................................................................................................33
11.1 Pressure drop characteristics FriwaMidi..................................................................... 34
11.2 Pressure drop characteristics FriwaMaxi.................................................................... 34
12 Commissioning report....................................................................................................35

1General Information
4 99640x5xx-mub-en – V01 2020/06
1General Information
1.1 Scope of these instructions
These instructions describe the installation, commissioning, function and operation of the
domestic hot water modules FriwaMidi and FriwaMaxi. The chapters called [specialist] are
intended for specialists only.
For other components of the system, such as tanks, controllers or pumps, please observe the
instructions of the corresponding manufacturer.
Station
Item
number
Controller
FC3.10
Pump,
primary
Circulation
Heat
exchanger
FriwaMidi
6405510
Grundfos
UPM2 25-75 / Copper
solder,
40 plates
FriwaMidi with
circulation
6405515
Grundfos
UPM2 25-75
Grundfos
UPM2 15-75 CIL
FriwaMidi
6405530
Grundfos
UPM2 25-75
/
Coated,
40 plates
FriwaMidi with
circulation
6405535
Grundfos
UPM2 25-75
Grundfos
UPM2 15-75 CIL
Station
Item
number
Controller
FC4.13
Pump,
primary
Circulation
Heat
exchanger
FriwaMaxi
6406510
Grundfos
UPML 25-105 / Copper
solder,
60 plates
FriwaMaxi with
circulation
6406515
Grundfos
UPML 25-105
Grundfos
UPM2 15-75 CIL
FriwaMaxi
6406530
Grundfos
UPML 25-105 /
Coated,
60 plates
FriwaMaxi with
circulation
6406535
Grundfos
UPML 25-105
Grundfos
UPM2 15-75 CIL
Carefully read these instructions before installation and commissioning. Save
these instructions in the vicinity of the installation for future reference.

1General Information
2020/06 99640x5xx-mub-en – V01 5
CE Declaration of Conformity
The domestic hot water module complies with the relevant directives and is therefore labelled
with the CE mark. The Declaration of Conformity is available upon request, please contact the
manufacturer.
1.2 About this product
The FriwaMidi and FriwaMaxi are domestic hot water modules which heat potable water
operating on the principle of a flow-type water heater.
The domestic hot water module is a premounted group of fittings checked for tightness and
used to transfer the heat between the buffer tank and the domestic hot water circuit. It contains
a preset controller and important fittings for the operation of the system:
•Ball valves in the primary circuit
•Piston valves in the secondary circuit
•Pressure relief valve in the secondary circuit
•Premounted controller
•Temperature sensor at the cold water inlet
•Temperature sensors at the heating flow
•Temperature sensor at the domestic hot water outlet
•Flow meter at the domestic hot water outlet
•Fill and drain valve to drain the heat exchanger
•Vent plug to vent the heat exchanger
1.3 Designated use
The domestic hot water module must only be mounted in heating installations between the
buffer tank and the domestic hot water circuit. Due to its design, the station must be mounted
and operated in a vertical position! The technical limit values specified in these instructions must
be observed.
Only use PAW accessories with the domestic hot water module.
Using the station contrary to its designated use will invalidate all liability claims.
Do not put the module into operation in case of any visible damage.

2Safety instructions
6 99640x5xx-mub-en – V01 2020/06
2Safety instructions
The installation and commissioning as well as the connection of electrical components require
technical knowledge commensurate with a recognised vocational qualification as a fitter for
plumbing, heating and air conditioning technology, or a profession requiring a comparable level
of knowledge [specialist].
The following must be observed during installation and commissioning:
•Relevant local and national regulations
•Accident prevention regulations of the professional association
•Instructions and safety instructions mentioned in these instructions
WARNING
Danger of scalding due to hot water!
Undesirable circulation of water in the primary circuit can cause the exit of water
of up to 90 °C at the withdrawal point.
External pumps must not be installed between the domestic hot water
module and the buffer tank.
The domestic hot water module must not be connected to a distribution
manifold of a heating circuit.
CAUTION
Risk of burns!
The valves, fittings and the pump may heat up to more than 95 °C during
operation.
The insulating shell must remain closed during operation.

2Safety instructions
2020/06 99640x5xx-mub-en – V01 7
ATTENTION
Material damage due to mineral oils!
Mineral oil products cause permanent damage in the material, resulting in its sealing
characteristics getting lost. We cannot be held liable for damage caused by seals damaged in
this way, and nor will we give warranty replacement for such parts.
It is imperative to prevent the EPDM sealing elements from making contact with
substances containing mineral oils.
Use a silicone- or polyalkylene-based lubricant free of mineral oil such as Unisilikon
L250L and Syntheso Glep 1 from Klüber or a silicone spray.
ATTENTION
Malfunction!
The domestic hot water module must be integrated in the potential equalisation of the
electric installation. If this is not guaranteed by the pipe system, establish a potential
equalisation connection to the main potential connection according to regulations.

3Product description
8 99640x5xx-mub-en – V01 2020/06
3Product description
Example: FriwaMaxi with circulation
Connections
1 Primary side: return to the buffer tank
2 Secondary side:
hot water circulation, return
3 Secondary side: cold water inlet
4 Secondary side: hot water outlet
5 Primary side: flow from the buffer tank
Equipment
A Ball valve with check valve
B Primary pump
C Non-return valve with drain valve
D Circulation pump
E Piston valve with drain valve
F Piston valve with drain valve
G Piston valve with drain valve and
temperature sensor
H Fill and drain valve and temperature
sensor
I Flow meter FlowSonic
J Plate heat exchanger
K Circulation line
L Vent valve (primary circuit)
M Temperature sensor and pressure relief
valve 10 bars, suitable for DHW
Only for the protection of the station.
Does not replace the pressure relief valve
that has to be mounted on site!
N Ball valve with check valve

4Dimensioning and planning
2020/06 99640x5xx-mub-en – V01 9
4Dimensioning and planning
The FriwaMidi and FriwaMaxi can only work flawlessly if the installation meets certain
requirements. Please take some time to plan the assembly.
WARNING
Danger of scalding due to hot water!
Undesirable circulation of water in the primary circuit can cause the exit of water
of up to 90 °C at the withdrawal point.
External pumps must not be installed between the domestic hot water
module and the buffer tank.
The domestic hot water module must not be connected to a distribution
manifold of a heating circuit.
Mounting example
FriwaMidi with optional circulation set (item no. 640412) and with optional return distribution
(FriwaMidi: item no. 640423, FriwaMaxi: item no. 640424)
Safety group
according to DIN
1988

4Dimensioning and planning
10 99640x5xx-mub-en – V01 2020/06
4.1 Dimensioning of the tank
The following table helps you to calculate the approximately required volume of the buffer tank.
Temperature in
the buffer tank
Domestic hot water
temperature set at the
controller
Required tank volume
per litre of hot water
50 °C 45 °C 1.3 litres
60 °C
45 °C 0.8 litres
50 °C 1.0 litre
55 °C 1.4 litres
70 °C
45 °C 0.7 litres
50 °C 0.8 litres
55 °C 0.9 litre
80 °C
45 °C 0.5 litres
50 °C 0.6 litres
55 °C 0.7 litres
Calculation example for the dimensioning of the buffer tank:
Temperature of the buffer tank: 60 °C
Required withdrawal flow rate at the tap: 20 l/min
Domestic hot water temperature set at the controller: 45 °C
How large must the tank be to allow for a continuous withdrawal during 20 minutes without
post-heating?
20 l/min x 20 min = 400 l
400 l x 0.8 = 320 l
The heated part of the buffer tank must have a volume of 320 litres.