Cetetherm Midi Wall TA Manual

DOC1364 Rev 11-03-2021
Installation, service and operating instruction Cetetherm Midi Wall TA
Heating and domestic hot water substation for apartment houses (10-30 apts.)

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Cetetherm Midi Wall TA
Installation, service and operating instruction
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Contents
1General .................................................................................................................................... 3
1.1 Comfort......................................................................................................................................................3
1.2 Installation .................................................................................................................................................3
1.3 Long-term security.....................................................................................................................................3
1.4 CE-marking................................................................................................................................................3
1.5 Information about the document ...............................................................................................................3
1.6 General warnings ......................................................................................................................................4
2Operating instructions ........................................................................................................... 5
2.1 Operation...................................................................................................................................................5
2.2 Safety equipment/inspection .....................................................................................................................5
3Product overview, flowchart and measure sketch .............................................................. 6
3.1 Schematic diagram, main components .....................................................................................................7
3.2 Option 3-point HB metering.......................................................................................................................7
3.3 Measure sketch Midi Wall TA....................................................................................................................8
4Installation............................................................................................................................... 9
4.1 Unpacking..................................................................................................................................................9
4.2 Preparation................................................................................................................................................9
4.3 Mounting....................................................................................................................................................9
4.4 Mounting the options ...............................................................................................................................10
4.5 Adjustments and settings for start up......................................................................................................10
4.6 Dismantlement.........................................................................................................................................10
4.7 Connection overview ...............................................................................................................................11
5Electrical installation............................................................................................................ 12
5.1 General....................................................................................................................................................12
6Pump settings and capacity ................................................................................................ 12
6.1 General....................................................................................................................................................12
6.2 DHWC pump Grundfos UPM3 DHW 15–70 CIL3, capacity....................................................................12
6.3 Heating circuit pump Grundfos UPMXL25-125 180 Auto, settings and capacity....................................13
6.3.1 Changing pump curve setting ............................................................................................................14
6.4 Heating circuit pump Grundfos Magna3 25–100, settings and capacity.................................................15
6.4.1 Heating circuit pump Grundfos Magna3 25-100, capacity.................................................................15
6.4.2 Grundfos Eye operating indications ...................................................................................................15
7Service instructions ............................................................................................................. 16
7.1 Tap water, service instructions................................................................................................................16
7.1.1 Tap water too cold..............................................................................................................................16
7.1.2 Tap water too warm ...........................................................................................................................16
7.1.3 Hot water temperature unstable.........................................................................................................16
7.1.4 Nosie in the DHWC system................................................................................................................17
7.2 Heating system, service instruction.........................................................................................................17
7.2.1 Heating system temperature too high or too low ...............................................................................17
7.2.2 No heating ..........................................................................................................................................17
7.2.3 Noise in the radiator system...............................................................................................................18
7.2.4 Heating temperature unstable............................................................................................................18
7.2.5 Heating system often needs topping up.............................................................................................18
8Service actions for the installer .......................................................................................... 19
8.1 Check the function of the hot water valve and actuator ..........................................................................19
8.2 Check the function of the heating actuator and valve .............................................................................20
8.3 Check DHWC pump ................................................................................................................................21
8.4 Check the volume take-up and pressure equalizing of the expansion vessel ........................................21
9Maintenance and repairs...................................................................................................... 22
9.1 Cleaning the district heating strainer.......................................................................................................22
9.2 Clean the heating circuit strainer.............................................................................................................22
9.3 Change the complete DHWC pump or pump components.....................................................................23
9.4 Change the complete heating pump or pump components ....................................................................24
9.5 Change the heating or hot water valve ...................................................................................................25

Cetetherm Midi Wall TA
Installation, service and operating instruction
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9.6 Change the expansion vessel .................................................................................................................25
10 Options .................................................................................................................................. 26
10.1 Safety thermostat ....................................................................................................................................26
10.1.1 Installing the safety thermostat ..........................................................................................................26
10.2 3-point or 2+1-point HB metering ............................................................................................................26
10.3 Mounting floor stand................................................................................................................................27
10.4 Mounting actuator....................................................................................................................................27
10.5 Balancing valve DHWC ...........................................................................................................................28
11 Technical data and performance......................................................................................... 30
11.1 Operation data Midi Wall 70 ....................................................................................................................30
11.2 Operation data Midi Wall 100 ..................................................................................................................31
11.3 Operation data Midi Wall 130..................................................................................................................32
11.4 Operation data Midi Wall 160..................................................................................................................33
11.5 Technical data .........................................................................................................................................33

Cetetherm Midi Wall TA
Installation, service and operating instruction
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1 General
Cetetherm Midi Wall is a complete, ready-to-install heating network substation for heating and hot water. It is
designed for buildings with a primary connection to a heating network. Cetetherm has years of experience in
heating network technology and has developed Midi Wall with well-planned pipe work and with all components
easily accessible for inspection and possible future servicing.
1.1 Comfort
Midi Wall has fully automatic temperature control for hot water. The hot water is controlled and maintained at
the desired temperature.
1.2 Installation
Before installation this manual must be read.
Well planned pipe work make installation very simple. The Midi Wall is designed for hanging on the wall.
1.3 Long-term security
All components are adjusted together and undergo thorough function testing in accordance with ISO 9001:2015
quality assurance system.
For future servicing requirements, all components are easily accessible and individually replaceable.
1.4 CE-marking
Midi Wall is CE-marked to certify that the substation conforms to international safety regulations. To maintain
the validity of the CE marking, only identical replacement parts must be used.
1.5 Information about the document
All pictures in this document are general images.
Mid Wall is available in different models and levels of equipment.

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Installation, service and operating instruction
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1.6 General warnings
The installation work must be carried out by an authorized installation contractor. Before the
system is taken into operation, it must be pressure tested in accordance with relevant regulations.
The temperature and the pressure of the district heating water are very high. Only qualified
technicians can work with the district heating substation. Incorrect operation may cause serious
personal injury and result in damage to the building.
If the hot water temperature is set too high, people may be scalded. If the hot water temperature is
set too low, unwanted bacteriological growth may occur in the hot water system. This can result in
serious personal injury.
Parts of the Midi Wall may get very hot and should not be touched.
Before the substation is connected to the electrical supply, make sure that the secondary heating
system is topped up with water. Starting up the system without water will damage the circulation
pump.
When starting up the district heating substation: to avoid the risk of scalding, make sure that no-
one draws any hot water until the hot water temperature has been adjusted.
Start district heating circulation by first opening the valve in the district heating supply and then
return lines, to avoid pollutions in the system. Open the valves slowly to avoid pressure surges.
Do the same way with the heating circuit, first open the valve for heating supply then return.
Do not shut of the electrical supply to the operator control panel. This will damage the circulation
pump, valves, actuators etc.
The heating station should be placed in a locked space, non-accessible for unauthorized
personnel.

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Installation, service and operating instruction
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2 Operating instructions
2.1 Operation
The temperature and pressure of the incoming heating network water from the culvert network are very high.
For this reason, only the heat from this water is used. The heating network water does not enter the heating
and hot water systems of the building.
The heat from the heating network water is transferred to the heating and hot water systems of the building in
the heat exchangers. The heat is transferred through thin plates of acid-resistant stainless steel which keep the
heating network water separate from the systems in the building.
Midi Wall has automatic temperature control for hot water.
The hot water temperature is controlled by a temperature control system which is set to about 55 ºC.
After adjustment, the Midi Wall operates completely automatically. However, in hard water areas it is advisable
to be attentive and to remedy any faults in good time if the temperature of the hot water is too high; otherwise
the risk of lime deposits in the heat exchanger may increase.
2.2 Safety equipment/inspection
•Daily inspection to check for leaks from pipes or components.
•Weekly inspection to make sure that the operation of the heating and hot water control systems is
stable and that the temperature does not fluctuate. Temperature hunting causes unnecessary wear of
valves, actuators and heat exchangers.
•Every three months check the safety valves and the pressure in the heating system.
To check the operation of a safety valve, turn its wheel/knob until water escapes from the valve, then close the
wheel/knob quickly. Occasionally a safety valve may open automatically to release excess pressure. After a
safety valve has been open it is important that it closes properly and does not drip.
Hot water temperature in apartments or one family houses can be set to about 55°C. If the temperature is set
too high, there is a risk of scalding. Setting the hot water temperature too low may result in unwanted
bacteriological growth in the hot water system.
The heating system is topped up via the topping up valve. Be sure to close the valve when the correct pressure
is reached. The water used to top up the system contains oxygen and may cause corrosion in the system. For
this reason, the system should be topped up as seldom as possible, at most once
If a joining must be loosened and then re-installed, for example when installing the substation or when
replacing a filter unit, the joining gaskets should be exchanged to prevent leaks.

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Installation, service and operating instruction
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3 Product overview, flowchart and measure sketch
Picture 1
1.
Heat exchanger, heating
16.
Shutoff valve, heating return
2.
Heat exchanger, DHW
17.
Strainer, heating return
3.
Control valve, heating
18.
Safety valve, heating
4.
Control valve, DHW
19.
Shutoff valve, heat supply
5.
Shutoff valve, cold water
20.
Pump, heating
6.
Check valve, cold water
22.
Actuator, DHW *
7.
Filling valve
23.
Actuator, heating *
8.
Hose
A.
Heating return
9.
Safety valve, cold water
B.
Heating supply
10.
Shutoff valve, DHWC
C.
District heating supply
11.
Pump, DHWC
D.
DHW
12.
Non-return valve, DHWC
E.
CW
13.
Shutoff valve, DHW
F.
DHWC
14.
Strainer, primary in
G.
District heating return
15.
Dummy, heat meter
H.
Connection expansion vessel
*) option

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Installation, service and operating instruction
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3.1 Schematic diagram, main components
Picture 2
3.2 Option 3-point HB metering
Picture 3
1.
Welded filter
2.
Shut off valves
3.
Manometer clock
4.
Sensor pocket energy meter primary in
5.
Sensor pocket energy meter primary out
6.
Flanged dummy 260mm energy meter

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Installation, service and operating instruction
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3.3 Measure sketch Midi Wall TA
Picture 4

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Installation, service and operating instruction
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4 Installation
4.1 Unpacking
•Remove the transport packaging and check that the product has not been damaged in transit and that
the consignment agrees with the specifications.
•When lifting the unit, take care not to apply stress to pipes and heat exchangers as this may weaken
them Lift the unit in the frame; avoid lifting the unit by holding the heat exchangers. Use pallet lift where
applicable, if using back straps these should be attached to the substructure of the substation.
NOTE: Risk of injury lifting heavy objects.
4.2 Preparation
•Choose a suitable installation area in accordance with official regulations.
The system may generate sounds during operation caused by pumps, regulators systems, flows etc.
This should be taken into consideration during installation of the unit, so that possible operational
sounds affect the surroundings as little as possible. This means that the system should be installed on
well-insulated walls, such as outer walls or on concrete walls.
•Check the applicable regulations of the district heating supplier. The available differential pressure
should be at least 100 kPa and at most 600 kPa. Where the differential pressure is higher, a differential
pressure controller should be added to the installation.
•Flush heating and hot water systems.
4.3 Mounting
•Mount the substation on a wall with screws and bolts suitable for mounting wall material and substation
weight. The distance between floor and screw bracket should be 1420 mm. Note that distance between
screws are 400 mm. Mount the floor support on the central, use the middle mounting hole. Raise the
central and mount it on the wall.
•Place the substation so that connections, adjustment equipment and safety valves are easily
accessible.
•Mount the shutoff valves on district heating supply and return. Shutoff valves are not supplied.
•Connect the pipe works to the connection points, see 4.7 Connection overview.
•When executing hot work on or close by the substation, all incendiary components should be
demounted and removed.
•With supply temperatures above 100°, it is recommended that the actuator is tilted or put down.
Picture 5
•Take rules and instructions regarding hot work into account.
•Connecting pipes shall be suspended so that their weight does not stress the unit.
•All connecting pipes within and connecting to the units’ system shall be insulated according to
standards and regulations.
•Drainage pipes from safety valves must be taken to floor gully.

Cetetherm Midi Wall TA
Installation, service and operating instruction
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•Energy meters must be installed at a prepared location, replacing a gauge block, or following the
instructions of the energy supplier.
NOTE:the connection pipe between the valves is just for draining.
•Retighten all connections, including those made at the factory. If connections need retightening after
the installation has been taken into service, the system should be depressurised before retightening. If
the system is not depressurised before retightening, gaskets will be damaged.
•Required expansion volume shall be installed and provided with adequate pre-charge before start up.
•Remount plugs in drain valves after possible draining of circuit.
4.4 Mounting the options
•If the substation is connected to a system sensitive to high temperature or to a low temperature system,
for example floor heating, a safety thermostat must be mounted and activated before start up.
See 10.1 Safety thermostat.
•If the substation shall be provided with a 3-point HB metering, see mounting instructions
10.2 3-point or 2+1-point HB metering.
•If the substation shall be provided with a floor stand, see mounting instructions
10.3 Mounting floor stand.
•If the substation shall be provided with actuators, see mounting instructions 10.4 Mounting actuator.
4.5 Adjustments and settings for start up
•Open incoming cold-water supply and fill the service water and heating circuits, bleeding off any
trapped air.
•Check the operation and opening pressures of the safety valves.
•Adjust the hot water temperature by having a hot water tap open at normal flow rate for a time.
Measure the temperature at the draw-off point with a thermometer. The temperature should be
approximately 55°C. It takes about 20 seconds to get stable tap water temperature.
NOTE: Make sure that no cold water is mixed with hot water while making this adjustment.
•Start the heating circulation pump at the strongest flow setting during some minutes. The pressure
should be at least 100 kPa during winter and at least 60 kPa during summer.
•Set the pump capacity of the heating circulation pump according to chapter 6, Pump settings and
capacity. Use the lowest setting that manages the heating demand for best electrical efficiency.
•The property owner must be informed on how to operate, adjust and maintain the unit. It is overly
important to inform about the safety systems and the risks associated with the high pressure and
temperature of the district heating systems water supply.
4.6 Dismantlement
When the time comes for the substation to be dismantled and scrapped it must be disposed of in the correct
manner in accordance with local or national regulations.

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Installation, service and operating instruction
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4.7 Connection overview
Picture 6
1
Heat Supply G1 1/4"
5
DHW G1”
2
Heat Return G1 1/4”
6
DH Supply DN25, weld
3
CW G1”
7
DH Return DN255, weld
4
VVC G1”

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Installation, service and operating instruction
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5 Electrical installation
5.1 General
The wiring in Midi Wall conforms to the applicable rules for CE marking and has undergone electrical safety
testing and function testing. For permanent installation must the substation be connected to an all-pole isolated
switch. This must be done by a duly qualified electrician.
The substation must be connected to a grounded power outlet.
6 Pump settings and capacity
6.1 General
Mini Wall is equipped with two circulation pumps, one for the hot water circulation, DHWC-pump, and one for
the heating circuit.
The DHWC pump is a speed-controlled, high-efficiency pump.
The circulation pump for heating circuit is a pressure-controlled pump. The pump for heating circuit is available
in two different models.
6.2 DHWC pump Grundfos UPM3 DHW 15–70 CIL3, capacity
Picture 7
Picture 8
Green LED
Red LED
No external control
●
External control
●1
Alarm
●
1) 12 flashes per second
.

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Installation, service and operating instruction
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6.3 Heating circuit pump Grundfos UPMXL25-125 180 Auto, settings and capacity
Picture 9
Pumpkurva
MAX.Hnom
CP1
7,5 m
CP2
10 m
CP3
12,5 m
PP1
8 m
PP2
9,5 m
PP3
11 m

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The heating pump is internally controlled via digital pulse-width modulation.
The user interface allows to select between six control curves in two control modes:
•three proportional pressure curves (PP)
•three constant pressure/power curves (CP).
The pump is factory preset to Proportional pressure curve, PP2.
Flashing fast
PP1
Flashing fast
PP2
Flashing fast
PP3
Flashing slow
CP1
Flashing slow
CP2
Flashing slow
CP3
Picture 10, LED indication of the curve setting
6.3.1 Changing pump curve setting
Picture 11, Serial curve setting
1. Push the button for two seconds
Pump goes to setting mode - LED starts flashing.
2. With each push, the setting changes:
LED 1-2-3 are permanently on, and then the control curve and mode is changed.
3. Flashing mode:
• Fast: Proportional pressure
• Slow: Constant pressure/power
4. After ten seconds not pushing the button:
• Setting is adapted.
• Pump returns to operating mode
5. LED 1 or 2 or 3 is permanently on.
• Pump is running with the selected curve and mode.

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6.4 Heating circuit pump Grundfos Magna3 25–100, settings and capacity
The pumps have been factory-set to AUTOADAPT without automatic night setback.
AUTOADAPT (factory set)
•Recommend control mode for most heating systems.
•Automatically adjusts the pump to actual system characteristics.
•Ensures minimum energy consumption and a low noise level.
•Reduced operating costs and increased comfort.
6.4.1 Heating circuit pump Grundfos Magna3 25-100, capacity
Picture 12
6.4.2 Grundfos Eye operating indications
Grundfos Eye
Indication
Cause
No lights are on. The power is off.
The pump is not running.
Two opposite green indicator lights
running in the direction of rotation
of the pump.
The power is on.
The pump is running
Two opposite green indicator lights
are permanently on.
The power is on.
The pump is not running.
One yellow indicator light running
in the direction of rotation of the
pump.
Warning.
The pump is running.
One yellow indicator light is
permanently on.
Warning.
The pump has stopped.
Two opposite red indicator lights
flashing simultaneously.
Alarm.
The pump has stopped.
One green indicator light in the
middle is permanently on in
addition to another indication.
Remote-controlled.

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Installation, service and operating instruction
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7 Service instructions
To avoid the risk of scalding, make sure that no-one draws any water while servicing the
substation.
Grey marked service actions must be carried out by an authorized service technician.
NOTE: Make sure that the Midi Wall substation has been correctly installed.
7.1 Tap water, service instructions
7.1.1 Tap water too cold
Reason Action
District heating supply too low Check the primary inlet temperature
The temperature can be checked by means of the energy meter,
minimum 65ºC, or at the district heating medium supply.
District heating strainer clogged See 9.1 Cleaning the district heating strainer.
Hot water valve and/or actuator does
not work
See 8.1 Check the function of the hot water valve and actuator..
7.1.2 Tap water too warm
Reason Action
Hot water valve and/or actuator does
not work
See 8.1 Check the function of the hot water valve and actuator.
7.1.3 Hot water temperature unstable
Reason Action
Pending differential pressure Check available differential pressure and the primary inlet
temperature
The temperature can be checked by means of the energy meter,
minimum 65ºC, or at the district heating medium supply.
Faulting settings for drain hot water Check pre-set parameters on control panel display
Check set value for drain hot water.
DHWC pump is not running Check that the electrical power is on.
See 8.3 Check DHWC pump.
District heating strainer clogged See 9.1 Cleaning the district heating strainer.

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Installation, service and operating instruction
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7.1.4 Nosie in the DHWC system
Reason Action
The DHWC pump capacity set too high Reduce the pump capacity
Reduce the pump capacity by selecting a lower setting on the pump
when needed.
Air in the DHWC pump Vent the DHWC pump
Set the pump to speed III. Loosen the pump motor end nut to and let it
stay opened until the air in the pump is released. When the pump has
been vented, i.e. when the noise has ceased, set the pump according
to the recommendations.
The DHWC pump motor or pump
component damaged
Change pump components or the complete DHWC pump
See 9.3 Change the complete DHWC pump or pump components.
7.2 Heating system, service instruction
7.2.1 Heating system temperature too high or too low
Reason Action
The heating control equipment may
need to be adjusted
Check and adjust the heating curve
See separate instruction.
Heating circuit strainer clogged See 9.2 Clean the heating circuit strainer.
Heating valve and/or actuator does not
work
See 8.2 Check the function of the heating actuator and valve.
7.2.2 No heating
Reason Action
Circulation pump not running Check that the electrical power is on.
Check pre-set heating parameters in the controller.
Air pockets in the substation or in the
heating circuit
Check the circulation pump
If the pump fails to start after stopping, start the pump at the highest
setting.
Vent the pump
The pump is self-venting.
Possible remaining air in the pump may cause noise. This noise
ceases after a few minutes run time.
Heating circuit strainer clogged See 9.2 Clean the heating circuit strainer.

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Installation, service and operating instruction
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7.2.3 Noise in the radiator system
Reason Action
The heating pump capacity set too
high
Reduce the pump capacity
Reduce the pump capacity by selecting a lower setting on the pump
when needed.
Air in the heating pump Vent the pump
The pump is self-venting.
Possible remaining air in the pump may cause noise. This noise
ceases after a few minutes run time.
The heating pump motor or pump
component damaged
Change pump components or the complete pump
If it is necessary to change the driving side of the pump, it can be
dismantled without removing the entire pump.
See 9.4 Change the complete heating pump or pump components.
7.2.4 Heating temperature unstable
Reason Action
Pending differential pressure Check available differential pressure and the primary inlet
temperature
The temperature can be checked by means of the energy meter,
minimum 65ºC, or at the district heating medium supply.
District heating strainer clogged See 9.1 Cleaning the district heating strainer.
7.2.5 Heating system often needs topping up
Reason Action
Leaks in the substation or in the
system
Check the substation and the system for leaks
Leaks from the substation or the heating system causes pressure
drops.
Repair any leaks on the substation.
The heating system safety valve is
leaking or does not work
Check the heating system safety valve
Check that the safety valve is not leaking and that it works properly.
Check the safety valves’ function by turning the wheel/knob until water
runs out of the valve’s waste pipe and then close the valve quickly.
The expansion vessel cannot handle
the systems volume changes
See 8.4 Check the volume take-up and pressure equalizing of the
expansion vessel.