CTC Union EcoZenith i255 Series Manual

Providing sustainable energy solutions worldwide
162 505 67-1 2020-08-27
Important!
• Read carefully before use, keep for future reference.
• Translation of the original instructions.
Installation and Maintenance Manual
CTC EcoZenith i255
400V 3N~/ 230V 1N~/ 230V 3~

162 505 67-1 2020-08-27
Installation and Maintenance Manual
CTC EcoZenith i255

4CTC EcoZenith i255
Table of Contents
Congratulations on your new product _______________________ 5
Important to remember! ______________________________________________ 6
Safety instructions _______________________________________________________ 7
Checklist _______________________________________________________________________ 9
1. Your home’s heating settings_____________________________ 10
2. Technical data _____________________________________________________ 14
2.1 Table 400V 3N~ _____________________________________________14
2.2 Table 230V 1N~/230V 3~________________________________15
2.3 Measurements_________________________________________________16
3. Function description___________________________________________ 17
4. Parameter list ______________________________________________________ 18
5. Control system ____________________________________________________ 19
5.1 Quick start touchscreen____________________________________20
6. Detailed menu descriptions _______________________________ 22
6.1 Start menu ______________________________________________________22
6.2 Alarm management__________________________________________22
6.3 Heating/Cooling_______________________________________________23
6.4 DHW ______________________________________________________________26
6.5 Ventilation _______________________________________________________26
6.6 Weekly program_______________________________________________27
6.7 Operation data_________________________________________________29
Installer ___________________________________________________________________36
6.8 Display____________________________________________________________36
6.9 Settings __________________________________________________________38
6.10 Define_____________________________________________________________52
6.11 Service____________________________________________________________65
7. Operation and Maintenance ______________________________ 69
8. Troubleshooting/appropriate measures ___________ 70
8.1 Information messages ______________________________________ 72
8.2 Alarm messages ______________________________________________73
9. Installation____________________________________________________________ 76
9.1 Transportation__________________________________________________76
9.2 Unpacking_______________________________________________________ 76
9.3 Recycling ________________________________________________________76
9.4 Standard delivery* ____________________________________________ 76
10. Pipe installation___________________________________________________ 77
10.1 Filling ______________________________________________________________77
10.2 Schematic diagram __________________________________________79
10.3 Connection to heat pump _________________________________82
10.4 Schematic diagram of passive cooling – Combined
cooling/heating ________________________________________________84
10.5 Schematic diagram of passive cooling in separate
heating circuits.________________________________________________85
11. Electrical installation___________________________________________ 86
11.1 Electrical installation _________________________________________86
11.2 Positioning of electrical components __________________87
11.3 Electrical connection to heat pump ____________________88
11.4 Extra low voltage protection ______________________________90
11.5 Settings to be carried out by the installation electri-
cian ________________________________________________________________93
11.6 Connection of pump (G46) to Differential thermostat
function___________________________________________________________96
11.7 Connection of sensor (B46) to Differential thermo-
stat function ____________________________________________________96
11.8 Resistances for sensors____________________________________96
11.9 Component list, wiring diagram _________________________97
11.10 Wiring diagram 400V 3N~________________________________ 98
11.11 Wiring diagram 230V 1N~______________________________ 100
11.12 Wiring diagram 230V 3~ ________________________________ 102
12. Installation Communication _____________________________ 104
12.1 Installing the network cable _____________________________ 105
12.2 CTC Remote - Screen Mirroring_______________________ 106
12.3 MyUplink - App______________________________________________ 106
13. First start____________________________________________________________ 107

5CTC EcoZenith i255
• CTC EcoAir 610M
• CTC EcoAir 614M
• CTC EcoAir 622M*
• CTC EcoAir 406
• CTC EcoAir 408
• CTC EcoAir 410
• CTC EcoAir 510M
• CTC EcoAir 520M*
• CTC EcoPart 406
• CTC EcoPart 408
• CTC EcoPart 410
• CTC EcoPart 412*
Congratulations on your new product
You have just purchased a CTCEcoZenithi255, with which we hope you will be very pleased. Read about how you
can take care of your boiler on the following pages.
Save this manual containing the installation and maintenance instructions. If it is properly maintained, you will be able
to enjoy the use of your CTC EcoZenith i255 for many years. This manual will provide all the information you will need.
The complete system tank
The CTC EcoZenith i255 is a complete system tank which meets your home’s heating and DHW requirements. It
has a built-in electric heater and is equipped with a motorised mixing valve which ensures that correct and even
temperatures are supplied to your heating circuit. The CTC EcoZenith i255 has a built-in circulation pump for
connection to a heat pump.
CTC EcoZenith i255 is only approved for installation together with the following products.
!Information and energy labelling
stickers for the package in question
must be handed over to the final
consumer.
Eco design information about the current combination
(current package) can be retrieved/downloaded from
www.ctc.se/ecodesign where the energy labelling
stickers can also be printed.
*Consider the flow requirements, particularly with
the CTC EcoAir 622M, CTCEcoAir520M and
CTCEcoPart412 models. See also the “Anti Water
HammerAnti Water Hammer” function and use a larger
circulation pump if required.
All controls for the heat pump and charge pump are
built into the CTCEcoZenithi255. With this added
feature you achieve a very eco-friendly and energy-
saving heating system.

6CTC EcoZenith i255
Important to remember!
Check the following points at the time of delivery and installation:
• The product must be transported and stored in an upright position.
When moving the product, it can be placed temporarily on its back.
• Remove the packaging and check before installation that the product
has not been damaged in transit. Report any transport damage to the
carrier.
• Place the product on a solid foundation, preferably made of concrete.
If the product is to stand on a soft carpet, plates must be placed
under the feet.
• Remember to leave a service area of at least 1 metre in front of the
product.
• The product must not be placed below floor level either.
• Register the product for warranty and insurance via the website:
https://ctc.se/kundservice#garantiregistrering
https://www.ctc-heating.com/customer-service#warranty-registration
Serial number
Information for the property owner to note
Complete the fields below. This information is useful if any servicing work is required
Product: Serial no.:
Product: Serial no.:
Installation company: Tel. no.:
Date: Name:
Electrical installation company: Tel. no.:
Date: Name:
Subject to changes with no liability for misprints.
!
If these instructions
are not followed
during the installation,
operation and
maintenance of the
system, Enertech’s
liability under the
applicable warranty
terms is not binding.
!Information in
this type of box
[!] is particularly
important for
correctly installing
and using the
product.
iInformation in this
type of box [i] is
intended to help
ensure that the
product functions
optimally.

7CTC EcoZenith i255
Turn off the power with an omnipolar switch before doing any work on the product.
The product must be connected to protective earth.
The product is classified as IPX1. The product must not be rinsed with water.
When handling the product with a hoist ring or similar device, make sure that the
lifting equipment, eyebolts and other parts are not damaged. Never stand under the
hoisted product.
Never jeopardise safety by removing bolted covers, hoods or similar.
Any work on the product’s cooling system should be carried out by authorised
personnel only.
The product’s electrical systems should only be installed and serviced by a qualified
electrician.
-If the supply cord is damaged, it must be replaced by the manufacturer, its service
agent or similarly qualified persons in order to avoid a hazard.
Safety valve check:
-Safety valve for boiler/system to be checked regularly.
The product must not be started if it is not filled with water; instructions are in the
“Pipe installation” section.
WARNING: Do not switch on the product if there is a possibility that the water in the
heater is frozen.
This device can be used by children from the age of eight years and above and by
people with reduced physical, sensory or mental ability or lack of experience or
knowledge if they have been taught, either with supervision or with the instructions
provided, how to use the device safely and understand the risks involved. Children
should not play with the device. Cleaning and maintenance should not be carried
out by children without supervision.
If these instructions are not followed when installing, operating and maintaining the
system, Enertech’s commitment under the applicable warranty terms is not binding.
Safety instructions

8CTC EcoZenith i255

9CTC EcoZenith i255
Checklist
The checklist must always be completed by the installation engineer
• If a service is performed, you may be required to provide this document.
• Installation must always be done according to the installation and maintenance instructions.
• Installation must always be carried out in a professional manner.
• Following installation, the unit must be inspected, functional checks performed and the customer informed.
The points below must be checked off.
Pipe installation
CTC EcoZenith i255 filled, positioned and adjusted in the correct manner according to the instructions.
CTC EcoZenith i255 Product positioned so that it can be serviced.
Capacity of circulation pump(s) for required flow.
Open radiator valves and other relevant valves.
Tightness test.
Bleeding and pressurising the system.
Safety valve function test.
Waste pipe connected to floor drain.
Electrical installation
Power switch.
Correct and taut wiring.
Primary flow sensor, return sensor + any required sensors for selected system.
Outdoor sensor.
Room sensor (optional).
Accessories.
Heat pump activated and started.
Electric power and fuse, adapted for the property, in normal operation and backup mode.
Customer information (adapted to the relevant installation)
Start-up with customer/installer.
Menus/controls for selected system.
Installation and Maintenance Manual handed over to the customer.
Check and filling, heating circuit.
Fine-tuning information, heat curve.
Alarm information.
Mixing valve.
Safety valve function test.
Review warranty terms and conditions with the customer.
Register your Installation Certificate at ctc.se. (ctc-heating.com).
Information on fault reporting procedures.
______________________________________ ______________________________________
Date/Customer Date/Installer

10 CTC EcoZenith i255
iThe set heating curve always takes priority. The room sensor can only increase
or decrease the heat beyond the set heating curve to a certain extent. Where
operating without a room sensor, the selected heating curve determines the
flow temperature supplied to the radiators.
The House Heating Curve
The heating curve is the central part of the product’s control system. It is the
heating curve which determines the compensated flow temperature requirements
for your property dependent upon the outdoor temperatures. It is important that
the heating curve is correctly adjusted, so that you achieve the best operation and
economy possible.
One property requires a radiator temperature of 30°C when the outdoor
temperature is 0°C, whilst a different property requires 40°C. The difference
between different properties is determined by the radiator surface area, the number
of radiators and how well insulated the house is.
Adjustment of Default Values for the Heating Curve
You define the heating curve yourself for your property by setting two values in
the product control system. This is achieved by selecting the options Inclination or
Adjustment under the "Installer/Settings/Radiator system" menu. Ask your installer
to help you set these values.
It is extremely important to set the heating curve and, in some cases, unfortunately,
this process may take several weeks. The best way of doing this, upon the initial
start-up, is to select operation without any room sensor. The system then operates
using the outdoor temperature reading and the property’s heating curve only.
During the adjustment period it is important that:
• the night reduction function is not selected.
• all thermostat valves on the radiators be fully opened. (This is to find the
lowest curve for the most economical use of the heat pump).
• the outdoor temperature is not higher than +5°C. (If the outdoor temperature
is higher when the system is installed, use the factory set curve until the
outdoor temperature falls to a suitable level).
• the radiator system is operational and correctly adjusted between different
circuits.
1. Your home’s heating settings

11
CTC EcoZenith i255
Adjusting the heating curve
The method described below can be used to adjust the heating curve correctly.
Adjustment if it is too cold indoors:
• If the outdoor temperature is lower than 0 degrees:
Increase the Inclination value by a couple of degrees.
Wait 24 hours to see if any further adjustment is required.
• If the outdoor temperature is higher than 0 degrees:
Increase the Adjustment value by a couple of degrees.
Wait 24 hours to see if any further adjustment is required.
Adjustment if it is too warm indoors:
• If the outdoor temperature is lower than 0 degrees:
Decrease the Inclination value by a couple of degrees.
Wait 24 hours to see if any further adjustment is required.
• If the outdoor temperature is higher than 0 degrees:
Decrease the Adjustment value by a couple of degrees.
Wait 24 hours to see if any further adjustment is required.
iIf the values set are too low, this may mean that the desired room temperature
is not being reached. You then need to adjust the heating curve, as necessary,
following the method shown above.
When the basic values have been set more or less correctly, the curve can
be finely adjusted directly using the Room temp. shown on the home menu
screen.
Appropriate Default Values
During installation you can seldom achieve a precise setting for the heating
curve instantly. In this case, the values given below may provide a good
starting point. Radiators with small heat-emission surfaces require a higher
primary flow temperature. You can adjust the gradient (heating curve
gradient) for your heating system under the "Installer/Settings/Radiator
system" menu.
Recommended values are:
Floor heating only Inclination 35
Low temperature system (well insulated houses) Inclination 40
Normal temperature system (factory setting) Inclination 50
High temperature system
(older houses, small radiators, poorly insulated) Inclination 60

12 CTC EcoZenith i255
Examples of Heating Curves
You can see in the diagram below how the heating
curve changes with different Inclination settings. The
gradient of the curve shows the temperatures that the
radiators require at different outdoor temperatures.
Curve Inclination
The inclination value which is set is the primary flow
temperature when the outside temperature is –15°C.
Primary Flow Temperature
Primary Flow Temperature
Primary Flow Temperature
Outside Temperature
Outside Temperature
Heating off, out
Outside Temperature
Adjustment
The curve can be parallel displaced (adjusted) by
the desired number of degrees to adapt to different
systems/houses.
An example
Inclination 60°C
Adjustment 0°C
In this example, the maximum outgoing primary flow
temperature is set at 55°C.
The minimum permitted primary flow temperature is
27°C (e.g. summer-time basement heating or the floor
circuits in a bathroom).
Inclination 50°C
Adjustment +5°C
Inclination 50°C
Adjustment 0°C
Heating off, out

13
CTC EcoZenith i255
ºC
ºC
Summer-time operation
All properties have internal heat gains (lamps, oven,
body heat, etc.), which means that the heating can be
switched off when the outdoor temperature is lower
than the desired room temperature. The better insulated
the house is, the earlier the heating from the heat pump
can be switched off.
The example shows the product set at the default value
of 18°C. This value, "Heating off, outside", can be
changed in the "Advanced/Settings/Heat System"
menu.
In systems with a radiator pump, the radiator pump
stops when the heat is switched off. The heating starts
up automatically when it is required again.
Automatic or remote-controlled summer period
The factory setting causes "summer" to commence
automatically at 18ºC, as "Heating mode" is set to
"Auto".
Heating,mode Auto (Auto/On/Off)
Auto means automatic.
On means that the heating is on. For systems with
a mixing valve and a radiator pump, the mixing valve
operates to the primary flow setpoint and the radiator
pump is on.
Off means that the heating is switched off. For systems
with a radiator pump, the radiator pump is switched off.
Heating, ext. mode - (- /Auto/On/Off)
Facility for remote control of whether the heating is to be
on or off.
Auto means automatic.
On means that the heating is on. For systems with
a mixing valve and a radiator pump, the mixing valve
operates to the primary flow setpoint and the radiator
pump is on.
Off means that the heating is switched off. For systems
with a radiator pump, the radiator pump is switched off.
- No selection means no function when activated.
Heating upHeating up
Outside Temperature
Heating off, out
Primary Flow Temperature Heating
switched
off

14 CTC EcoZenith i255
CTC EcoZenith i255 H CTC EcoZenith i255 L
400 V 3N~ 50 Hz
kW 15.04 15.04
kW 0 - 9.0 (0.3/0.6/0.9/1.2/.../9.0)
kW 0-9 (0/6/9)
kW 3+6 / 6+6 / 9+6
IP X1
CTC EcoZenith i255 H CTC EcoZenith i255 L
kg 182 167
mm 672 x 595 x 1886 672 x 595 x 1652
mm 1901 1659
CTC EcoZenith i255 H CTC EcoZenith i255 L
l 223
bar 2.5
°C 110
CTC EcoZenith i255 H CTC EcoZenith i255 L
l 5.7 Cu (8.5 Inox)
bar 10
°C 110
Electrical Data
Electrical data
Rated power el.
Electric heater, upper (adjustable, steps of 0.3 kW)
Electric heater, lower (adjustable)
Max. Electric heater
output with group fuse 16 / 20 / 25 A
IP class
Other data
Weight
Depth x Width x Height
Required ceiling height
Heating system
Water volume, Boiler (V)
Max. Operating pressure, Boiler (PS)
Max. Temperature, Boiler (TS)
Pressure drop for Mixing valve heating See Pressure drop diagram in the "Pipe installation" chapter.
Hot water system
Water volume, Hot water coil (V)
Max. Operating pressure, Hot water coil (PS)
Max. Temperature, Hot water coil (TS)
2. Technical data
2.1 Table 400V 3N~

15
CTC EcoZenith i255
CTC EcoZenith i255 L
1 x 230 V
CTC EcoZenith i255 L
3 x 230 V
230 V 1N~ 50 Hz 230 V 3~ 50 Hz
kW 12.04 14.04
kW
0-9
(0/2/3/4/5/6/7/9)
0-7
(0/1.2/2.4/3.5/4.6/ 5.8/7.0)
kW 0-3 (0/3.0) 0-7 (0/7.0)
IPX1
CTC EcoZenith i255 L
1 x 230 V
CTC EcoZenith i255 L
3 x 230 V
kg 167
mm 672 x 595 x 1652
mm 1659
CTC EcoZenith i255 L
1 x 230 V
CTC EcoZenith i255 L
3 x 230 V
l 223
bar 2,5
°C 110
CTC EcoZenith i255 L
1 x 230 V
CTC EcoZenith i255 L
3 x 230 V
l 5.7 Cu (8.5 Inox)
bar 10
°C 110
Electrical Data
Electrical data
Rated power el.
Electric heater, upper (adjustable)
Electric heater, lower (adjustable)
IP class
Other data
Weight
Depth x Width x Height
Required ceiling height
Heating system
Water volume, Boiler (V)
Max. Operating pressure, Boiler (PS)
Max. Temperature, Boiler (TS)
Pressure drop for Mixing valve heating See Pressure drop diagram in the "Pipe installation" chapter.
Hot water system
Water volume, Hot water coil (V)
Max. Operating pressure, Hot water coil (PS)
Max. Temperature, Hot water coil (TS)
2.2 Table 230V 1N~/230V 3~

16 CTC EcoZenith i255
54
302 348
1905
673
410
340
38
597
563
673
54
257
63
1617
497
73
595
190
114
344
423
1
8
7
9
10
4
3
2
5
6
10
10
2.3 Measurements
Low Model High Model
1. Bleeding
2. Safety/connection waste pipe 3/4” 22
3. Cold water connection Ø22
4. DHW Ø22
5. Radiator primary flow clamp ring Ø22
6. Radiator return Ø22 /expansion connection
7. From heat pump Ø22 (CTC EcoZenith i255L)
8. To heat pump Ø22 (CTC EcoZenith i255L)
9. Lifting sleeve 3/4" BSP
10. Socket for connecting external systems/EnergyFlex (behind the front plate)

17
CTC EcoZenith i255
3. Function description
The picture below shows the basic construction of CTC EcoZenith i255.
If a heat pump is connected, the energy in the air or bedrock/ground is
drawn up by the cooling system. The compressor then increases the
temperature to a usable level. Afterwards it releases the energy for the
heating circuit and DHW. The built-in electric heaters help when additional
heat is needed or when a heat pump is not connected.
Bivalent mixing valve
The automated mixing valve
ensures that an even heat is
continuously supplied to the
heating circuit.
Insulation
The heat pump’s tank is
insulated with die-cast
polyurethane foam for minimal
heat loss.
Heat pump pipe
CTCEcoZenithi255L is
equipped with connection
pipes for top connection.
Lower part
In the lower part of the coil
the DHW is pre-heated by
the water heated by the heat
pump. The larger section of
the coil is in this part.
Flow conditioner
The heated water from the
heat pump alternately heats
up the upper or lower part of
the tank.
Expansion connection
15 mm.
Heat medium pump
The adjustable-speed charge
pump transports the cold
water from the boiler to the
heat pump where the energy
from the air or bedrock/ground
is drawn up and taken back to
the boiler.
The boiler is supplied with a
circulation pump for a heat
pump of up to 12kW!
DHW finned coil
CTCEcoZenith i255 is
equipped with a well-
dimensioned finned coil made
of copper. Since DHW is not
stored, there is no risk of
legionella bacteria.
Upper electric heater
Built-in upper electric heater.
When connected to the heat
pump, the electric heater acts
as additional heat.
Lower electric heater
Built-in lower electric heater.
Not used in normal operation
when the heat pump is
connected.
Draining/expansion vessel
connection
Two connections in the lower
part of the product where
water from the boiler and
heating circuit can be drained
and an expansion vessel
connected.
Fresh water connections
Here you connect the
property’s fresh water
connections. The cold water
is led down and heated in
the lower part of the coiling.
Upper part
In the upper part of the coil,
hot water is reheated to the
desired temperature.

18 CTC EcoZenith i255
4. Parameter list
Heating circuit Factory
setting
User (set) value
Max primary flow °C 55
Min primary flow °C Off
Heating mode Auto
Heating mode, ext. –
Heating off, out °C 18
Heating off, time 120
Inclination °C 50
Adjustment °C 0
Night reduction down to °C 5
Room temperature lowered, Night
reduction°C
-2
Room temperature lowered, Holiday °C -2
Primary flow lowered, Night reduction°C -3
Primary flow lowered, Holiday°C -3
Alarm, low room temp. 5
Anti Water Hammer No
HP max DHW Yes
Upper tank Factory
setting
User (set) value
Stop temp HP °C 59
Start/stop diff °C 7
Max time upper tank 30
Max time lower tank 20
Electric heaters Factory
setting
User (set) value
Boiler upper °C 45
Boiler upper additional °C 57
Boiler upper extra DHW °C 60
Boiler upper max kW 5.5
Boiler lower °C 55
Boiler lower kW 6.0
Delay mixing valve min 180
Main fuse A 20
Conv. factor curr. sensors 1
Heat pump Factory
setting
User (set) value
Compressor Blocked
Stop at outside temp °C (air-to-water) -22
Brine pump to (liquid-to-water) Auto
Minimum run time 6
The tables show factory settings for important product parameters.
The installer can enter the set values in the column on the right as a reference for future adjustments.

19CTC EcoZenith i255
5. Control system
The CTC EcoZenith i255 has an advanced yet
straightforward control system with a touchscreen on
which all settings are entered directly.
The CTC EcoZenith i255 control system:
• monitors all functions in the system tank, heat
pump and heating system.
• allows for individual settings.
• Displays desired values, such as temperatures,
operation times, energy consumption and fault
signals.
• Allows for simple and structured value setting and
troubleshooting.
Factory values
CTC EcoZenith i255 is delivered with set factory values
which are suitable for a normal house with a normal
heating circuit. The CTC EcoZenith i255 automatically
adjusts the water temperature to the primary flow’s
current heating requirement. This is monitored by the
control system, which continuously ensures that you are
provided with optimum function and economy. These
values are easy to change as and when required. Ask
your installer to help you determine the correct values.
Heat pump
On delivery the CTC EcoZenith i255 is ready for
connection to a CTC heat pump –
This means that the control system already contains all
the controls for the heat pump. When the heat pump
has been defined (On), CTC EcoZenithi255 senses
which heat pump has been connected. "Installer/Define/
Heat Pump".
Once this has taken place the menus for the heat pump
are displayed. On delivery the compressor is blocked
and must be enabled. This is done in the "Installer/
Settings /Heat Pump" menu.
CTC EcoVent
The product is ready for connection with the CTC
EcoVent ventilation product.
The screen shows operating information with the CTC EcoAir
heat pump connected.
The screen shows operating information with the CTC EcoPart
heat pump connected.

20 CTC EcoZenith i255
Start menu
Back Select and save
Increase value
Decrease value
Decrease
value
Increase
value
Scroll & Swipe sideways
Single click = Select
Double click = Open
Room temperature Heating Circuit 1
Measured by Room Sensor 1.
For minor temperature adjustment: Click the
"Heating/Cooling" icon
• Measured temperature from room sensor and
desired setpoint are shown in brackets: Click "+"
or "-" to change the setpoint.
• Fine tuning without Room Sensor: Click "+" or "-"
to adjust the setting.
• Night reduction: Set a higher or lower temperature
at certain times of day. If active, "NR" is displayed
after the current temperature e.g. 24 NR (25).
Holiday: Set higher or lower temperatures on certain
days. If active, "S" is displayed after the current
temperature e.g. 24 S (25).
For greater temperature setting/adjustment: Click
"Installer/Settings/Heating Circuit 1"
• If the outdoor temperature is lower than 0°C:
Change inclination.
• If the outdoor temperature is higher than 0°C:
Change adjustment.
• Press "OK" to confirm change.
5.1 Quick start touchscreen
The illustration below shows the most common functions you need to set and use as the end customer.
Start menu
Heating/Cooling
Refer to the "Your home’s heating settings" chapter for
detailed information about heat settings. Menu: "Installer/Settings/Heating Circuit 1".
Next
Room temperature Heating Circuit 2
Measured by Room Sensor 2.
Tank temperature
Measured by DHW Sensor in upper
tank.
Outdoor temperature
Measured by Outdoor Sensor.