CTC Union EcoZenith i550 Pro Manual

162 105 20-1 2013-06-13
Installation and Maintenance Manual
CTC EcoZenith i 550 Pro

4CTC EcoZenith i550 Pro
General Information
No liability is accepted for any misprints. We reserve the right to make design changes.
Quick reference
Fill in the information below. It may come in useful if anything should happen.
Product: Manufacturing number:
Installer: Name:
Date: Tel. no.:
Electrical installer: Name:
Date: Tel. no.:
Table of Contents
GENERAL INFORMATION 4
Check list ____________________________________________________________________ 6
Important to remember! _____________________________________________ 7
Safety Instructions _____________________________________________________ 7
Scope of delivery________________________________________________________ 8
1. CTC EcoZenith i550 Pro design _________________________ 9
1.1 Main components____________________________________________ 9
2. CTC EcoZenith i550 Pro function _____________________ 10
2.1 Heating System_____________________________________________ 11
2.2 DHW ___________________________________________________________ 12
2.3 Heat pump ___________________________________________________ 13
2.4 Wood Boiler__________________________________________________ 16
2.5 Additional boiler (pellets, oil, gas, electricity) _______ 17
2.6 Solar Energy _________________________________________________ 18
2.7 Recharging Bedrock/Ground ___________________________ 19
2.8 External Hot Water Tank _________________________________ 20
2.9 Pool
____________________________________________________________ 20
2.10 External Buffer Tank _______________________________________ 21
2.11 Cooling CTC EcoComfort________________________________ 23
3. The House Heating Curve _________________________________ 24
4. DHW ___________________________________________________________________ 27
5. Technical data____________________________________________________ 29
6. Measurements ___________________________________________________ 30
7. Menu overview___________________________________________________ 31
7.1 Room temp. _________________________________________________ 32
7.2 DHW ___________________________________________________________ 32
7.3 Operation _____________________________________________________ 33
7.4 Installer (Time/Language – Settings)__________________ 34
7.5 Installer (Define system) __________________________________ 36
7.6 Installer (Service)____________________________________________ 38
8. Parameter list_____________________________________________________ 40
9. Detail Description Menus__________________________________ 42
9.1 Start menu ___________________________________________________ 42
9.2 Room temp. _________________________________________________ 43
9.3 DHW ___________________________________________________________ 45
9.4 Operation _____________________________________________________ 46
9.5 Installer ________________________________________________________ 54
10. Operation and Maintenance______________________________ 77
11. Troubleshooting/measures________________________________ 79
11.1 Information messages ____________________________________ 81
11.2 Alarm messages____________________________________________ 82
FOR THE INSTALLER 84
12. Transportation, unpacking and installation ______ 84
12.1 Transportation ______________________________________________ 84
12.2 Unpacking____________________________________________________ 84
12.3 Fitting rear insulation and plastic top cover_________ 84
13. Pipe installation _________________________________________________ 86
14. Schematic diagram____________________________________________ 98
15. Parts list ___________________________________________________________ 100
16. Electrical installation _______________________________________ 102
16.1 Positioning of electrical components ________________103
16.2 Heat pump power supply_______________________________104
16.3 Communication between the EcoZenith and CTC
EcoAir/CTCEcoPart______________________________________104
16.4 Low voltage 230V /400V (Heavy current) __________104
16.5 Sensor (Safety Extra-Low Voltage (SELV)) _________113
16.6 Night reduction/ripple control__________________________117
16.7 Current sensor connection _____________________________117
16.8 Settings made by the installation electrician ______118
17. Installation of optional immersion heater _______ 119
18. Installation of additional boiler________________________ 120
19. Parts list Wiring diagram _________________________________ 121
20. Wiring diagram main card 3x400V__________________ 122
21. Wiring diagram main card 1x230V__________________ 124
22. Wiring diagram for expansion card ________________ 126
23. Resistances for sensors__________________________________ 127
24. First start__________________________________________________________ 128
24.1 Before first start____________________________________________128
24.2 First start_____________________________________________________129
Declaration of Conformity______________________________________ 130

5
CTC EcoZenith i550 Pro
General Information
You have just bought a CTC EcoZenith i550 Pro, which
we hope you will be very pleased with. In the following
pages you can read about how to operate and maintain
your product. One part contains general information
and one part has been written for the installer. Keep
this manual containing the installation and maintenance
instructions. You will be able to enjoy the benefits
of your EcoZenith for many years, and this manual
provides all the information you will need.
The Complete System
The CTC EcoZenith i550 Pro is a complete system
which meets your home’s heating and hot water
requirements. It is equipped with a unique control
system that monitors and controls your entire heating
system regardless of how you choose to tailor it.
The CTC EcoZenith i550 Pro has a control
system that:
• monitors all hot water and heating system
functions;
• monitors and controls your heat pump, solar
panels, additional heat, buffer tank, pool, etc.;
• allows for individual settings;
• indicates desired values, for instance,
temperatures and energy consumption;
• facilitates settings in a simple and structured
manner.
Congratulations on buying your new product
Your CTC EcoZenith i550 Pro has built-in finned copper
coils which provide plenty of hot water and another
finned copper coil to handle the heat from solar panels.
The product also has a so-called cellar heat feature
during the summer and a floor feature which maximizes
the primary flow temperature.
Using the integrated night reduction function, you can
set and change the temperature in the property during
a 24-hour period, day by day, in blocks or as a vacation
function.
Service-friendly
Easily accessible electrical components, along with
effective troubleshooting functions in the control
program, make the EcoZenith easy to service. It is
supplied with a room sensor as standard, which is
equipped with LED lights that flash in the event of a
fault.
The EcoZenith is fully designed to work with the
CTCEcoAir 400 series outdoor air heat pump, the
CTC EcoPart 400 series bedrock/ground source heat
pump, solar panels, water-jacketed stove and an
additional boiler where present. The EcoZenith can
control a number of combinations and provide you with
an extremely flexible, eco-friendly and energy-saving
heating system.

6CTC EcoZenith i550 Pro
General Information
Check list
The check list must be completed by the installer.
• In the event of a service, this information may be called for.
• 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 should be inspected and checked for functionality.
Following installation, the unit must be inspected and functional checks performed
as indicated below:
Pipe installation
EcoZenith filled, positioned and adjusted in the correct manner according to the instructions.
EcoZenith positioned so that it can be serviced.
Capacity of the charge/radiator pump (depending on type of system) for the flow required.
Open radiator valves and other relevant valves.
Tightness test.
Bleed the system.
Safety valve function test.
The waste pipe is connected to the draining gutter.
Electrical installation
Compressor, direction of rotation (if heat pump installed).
Power switch
Correct tight wiring
Requisite sensors for applicable system
Outdoor sensor
Room sensors (optional)
Accessories
Information for the customer (adapted to current installation)
Start-up with customer/installer.
Menus/controls for selected system
Installation and maintenance manual supplied to the customer
Checks and filling, heating system
Trimming information, heat curve
Alarm information
Mixing valve
Safety valve function test
Warranty conditions
Information on procedures for fault registration
______________________________________ ______________________________________
Date / Customer Date / Installer

7
CTC EcoZenith i550 Pro
General Information
Important to remember!
Check the following points in particular at the time of delivery and installation:
• The CTC EcoZenith i550 Pro 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 CTC EcoZenith i550 Pro on a solid foundation, preferably
made of concrete. If the product needs to be placed on a soft carpet,
base plates must be placed under the adjustable feet.
• Remember to leave a service area of at least 1 m in front of the
product. Space is also needed around the product for installation of
insulation and plastic top cover. See the chapter on Transportation,
unpacking and installation in the section for the installer. The CTC
EcoZenith i550 Pro must not be lowered beneath floor level.
• Check for missing parts.
• The product must not be installed where the ambient temperature is
higher than 60°C.
Safety Instructions
The following safety instructions must be observed when handling, installing
and using the heat pump:
• All installation must be carried out by a qualified person in accordance
with applicable regulations.
• The product is only intended for vertical installation.
• Close the safety switch before doing any work on the product.
• Do not soak the product with water or any other liquid.
• When handling the product with a hoist ring or similar device, make
sure that the lifting equipment, eyebolts etc. are not damaged. Never
stand under the hoisted product.
• Never jeopardize safety by removing bolted covers, hoods or similar.
• Never jeopardize safety by deactivating safety equipment.
• Any work on the product should be done by authorised personnel only.
• Safety valve check:
– The safety valve for the boiler/system and hot tap water must be
checked on a regular basis. See the chapter on Operation and
maintenance.

8CTC EcoZenith i550 Pro
General Information
Scope of delivery
Standard delivery
• Multitank CTC EcoZenith i550 Pro
• Additional package with:
–Installation and Maintenance Manual
–Outdoor sensor
–Room sensor
–Safety valve 9 bar (tap water)
–Safety valve 2.5 bar (radiator system)
–Drainage valve
–Adapter between the drainage valve and the connection sleeve
–Sensor, 2 off (to and from pipes)
–Current sensor, 3 off
–Cover washer for connections, upper and lower tank, 8 off
–Cover washer for solar coil connections, 2 off
–Insulation for connection sleeves that are not used
–Sensor labelling
–Screw 4.2 x 14 graphite grey, 25 off + 2 extra
–Screw 4.2 x 14 zinc grey, 4 off + 2 extra
• Additional package with rear insulation sections and plastic top

9
CTC EcoZenith i550 Pro
General Information
1. CTC EcoZenith i550 Pro design
Control System
The EcoZenith is equipped with
an intelligent control system which
controls and monitors all parts of
the heating system. The EcoZ-
enith ensures that the most eco-
nomical way of heating the house
and the hot water is prioritised.
Finned Coil for Hot Water
The EcoZenith is equipped with a
well dimensioned finned copper
coil and does not contain any
heater which can rust. A low
temperature can be maintained
without the risk of legionella
bacteria.
Immersion heaters in Upper
Part of Tank
Built-in upper immersion heater.
When connected to a heat pump,
the immersion heater acts as
additional heat.
(The uppermost immersion heater
is an accessory).
Lower tank
In the lower part of the tank, hot
water is preheated in the coil by
the solar- or heat pump-heated
water.
Solar Coil Connections
The well dimensioned, 10 m long,
finned coil can be connected
directly to the solar panels.
Lower immersion heater
Built-in lower immersion heater.
Upper Tank Connections
The upper part of the tank, the
additional part, can be heated by
heat pump and connected to heat
sources such as electric, gas, oil
and pellet boilers. Heat from a
wood boiler is delivered to this part.
Connections are placed symmetri-
cally on both sides of the tank.
Insulation
The tank is insulated by 90-mm-
thick molded polyurethane foam
for minimum heat loss.
Lower Tank Connections
The heat pump and solar system
are connected to the lower tank.
Water to be heated by wood boiler
is taken from here, and heat which
is to be stored in a buffer tank is
also taken from this part. Connec-
tions are placed symmetrically on
both sides of the tank.
Insulated tank divider
Between the tank’s upper and
lower tank is an insulated tank
divider. This provides high tem-
peratures in the upper tank for
good hot water capacity and low
temperatures in the lower tank for
best operating economy.
Heat Distribution Pipes
The heat distribution pipes ensure
that heat from the solar coil is di-
rected to the upper tank and that,
after hot water is drawn off, cooled
water is directed to the lower part
of the tank to be heated again by
solar energy or heat pump.
Upper tank
In the upper part of the tank, the
warm water in the coil is heated
up to the desired temperature.
Bivalent Mixing Valve
The automated mixing valve
ensures that an even heat is
continuously supplied to the radia-
tor system. The valve has double
ports and takes the warm radiator
water from the solar and heat
pump heated water in the lower
part of the tank first.
Fresh Water Connections
Here you connect the property’s fresh
water connections. The cold water
is fed down to the lower part of the
coiling, where it is preheated.
Top Connection
For connection of expansion ves-
sel and/or safety valve.
This chapter illustrates the main components and describes the subsystems
which, in different configurations, form part of the main system. For more informa-
tion about the EcoZenith configurations, refer to the “Pipe connections” chapter.
1.1 Main components

10 CTC EcoZenith i550 Pro
General Information
upper tanklower tank
The CTC EcoZenith i550 Pro is a multi-tank with almost
unlimited possibilities.
The EcoZenith is intended for houses and properties with water-borne
heat. The multi-tank features include intelligent control, a water volume
of 540 litres, bivalent mixing valve, two hot water coils, a solar coil and
two 9 kW immersion heaters giving a total of 18 kW. You can easily add
another immersion heater as an accessory to provide total power of 27 kW,
controlled by the EcoZenith.
The control is specially adapted to simultaneously control up to three of
CTC’s heat pumps, but it will also control and optimise the following:
• Pool
• Energy storage in buffer tanks
• Three heating circuits simultaneously
• Solar panels and bore hole recharging
• Cooling (passive cooling), floor or fan convector
• Hot water circulation with time control
• Charging of extra domestic hot water tank
• Connected wood boiler, gas/oil boiler and pellets
The CTC EcoZenith is well-insulated with 90 mm PUR and is well provided
with connection options on both sides, ensuring clean and easy pipe
installations. It also provides for extensions and additions to the system in
the future.
The CTC EcoZenith i550 Pro is divided into two tanks which are isolated
from each other in order to be able to hold different temperatures in the two
tanks. This provides for optimal function and operating economy.
The upper and the lower tanks are connected by heat distribution pipes
which are especially developed for the solar energy to be able to form layers
optimally in the entire volume of the tank and act as flow-through of the tank
on wood operation, for instance. See figure.
See also Immersion heaters Menu in the Detail Description Menus
chapter (“Installer/Settings/Electric heaters”)
See also Lower tank Menu in the Detail Description Menus chapter:
“Installer/Settings/Lower tank”
2. CTC EcoZenith i550 Pro function
!Remember that
menus which have
not been defined
cannot be seen.

11
CTC EcoZenith i550 Pro
General Information
2.1 Heating System
The EcoZenith is equipped with a bivalent mixing valve, which always
delivers an even temperature, without variation, to the heating system.
Thebivalent mixing valve is controlled by an outdoor sensor and, optionally,
by a room sensor.
When operating with outdoor sensor alone, the desired curve inclination and
adjustment are set. These values differ from home to home and should be
adjusted to suit your needs.
A room sensor that is correctly positioned provides more comfort and
more heating system savings. The room sensor picks up the current indoor
temperature and adjusts the heat, for example when it is windy outside and
the house is losing heat, which the outdoor sensor is unable to register.
During solar insolation, or other instances when heat builds inside the house,
the room sensor can also reduce the heat, thus saving energy. Another way
to save energy is to use the night reduction function, which reduces the
indoor house temperature at certain times or periods, for example during the
night or when you are away on holiday.
The EcoZenith can control up to three heating systems, each with its own
room sensor. For instance, one radiator circuit plus two floor heating circuits.
The bivalent mixing valve always attempts to use the energy from the lower
tank first; this is especially important when a heat pump or solar panel
is connected to the EcoZenith. This ensures the system delivers good
operating economy and that the upper tank stays warm to provide an
abundance of hot water.
See also Heating system Menu in the Detail Description Menus chapter
(Installer/Settings/Heating circuit 1-3).
See also Room temperature Menu in the Detail Description Menus
chapter. You access the menu directly from the main menu.

12 CTC EcoZenith i550 Pro
General Information
2.2 DHW
The final heating of the hot water takes place in the upper tank. It also acts
as additional heating for the heating system when the lower tank is not
sufficient.
The hot water is heated using two finned copper tube coils of approx.
40metres connected in parallel. The coils preheat the water in the lower
tank and the water reaches maximum temperature in the upper tank. The
low inner volume and high rate of water turnover in the copper coil prevents
build-up of bacteria.
With double coils, high draw-off flows can be obtained, as the heat
conduction area is finned, on the inside as well as the outside. For more
information on settings and tips, please see the DHW chapter.
2.2.1 Hot Water Circulation
The hot water coil has a connection for hot water charging, which can be
used to heat an external cold water tank when greater tap capacity of DHW
is required, and allows connection of hot water circulation. This means that
hot water is always available at the tap. To save energy the HWC pump can
be time controlled from the EcoZenith.
See also Upper tank Menu in the Detail Description Menus chapter
(Installer/Settings/Upper tank).

13
CTC EcoZenith i550 Pro
General Information
upper tank
lower tank
port 1
port 2
2.3 Heat pump
The EcoZenith is designed with two parts in order to ensure the heat pump
operates to maximum possible economy.
The heat pump is connected via two diverting valves to the EcoZenith and
ensures that the heat is directed into the upper and lower tanks, respectively.
For instance, when the heat pump pumps towards the upper tank, the
diverting valves send the flow to the two uppermost connections, so that the
flow enters port 1 and exits through port 2.
The heat pump operates in two different ways, depending on whether it is
the upper tank or the lower tank being charged.
2.3.1 Upper tank
The final hot water heating takes place in the upper tank. This means that,
with a high upper tank temperature, an ample hot water supply is obtained.
The upper tank has a factory-set stop temperature of 55°C, which means
that the heat pump will work to achieve this temperature in the upper tank.
When hot water is being drawn off and the temperature in the upper tank
falls to 5°C below the stop temperature, the heat pump starts up and raises
the temperature towards the set stop temperature.
The stop temperature can be adapted to hot water needs and to the heat
pump model installed.
When there is also a need for heat in the house, the diverting valves will
automatically reverse direction and the heat pump continues to heat the
lower tank as soon as the stop temperature 55°C in the upper tank has
been reached. If the upper tank has not reached the stop temperature 55°C
within the factory-set 20 minutes of charging, the diverting valves reverse the
direction and the heat pump charges the lower tank. This is to prevent loss
of temperature in the heating system.
See also Upper tank Menu in the Detail Description Menus chapter
(Installer/Settings/Upper tank)

14 CTC EcoZenith i550 Pro
General Information
2.3.2 Lower tank
In the lower tank the heat pump operates to provide heat to the heating
system. Heat pump operation is of so-called floating condensation type.
However, the lower tank never drops below the set lowest temperature.
Floating condensation operation is where the heat pump heats to the
temperature required by the heating system. This temperature varies
depending on the outdoor temperature and which set inclination and
adjustment (the heat curve for the house) has been chosen. If a room sensor
is installed, this will affect the temperature required in the system. During
spring and autumn, when it is not so cold outside, a lower temperature is
needed for the heating system, but during winter a higher temperature is
needed to maintain the desired indoor temperature.
Savings from a heat pump are directly linked to the COP value. COP means
the output divided by the supplied power. COP 4 therefore means, for
instance, that the heat pump delivers 4 kW and uses 1 kW ( )
The lower the temperature the heat pump needs to deliver, the higher the
COP value obtained from the heat pump, as this will involve the compressor
working to better advantage.
Therefore, the heat pump heats only to the lower tank temperature the
heating system requires. This saves compressor life and maximizes operating
economy. The immersion heater, which is factory installed in the lower tank,
is blocked as long as the heat pump is operating.
The immersion heater is only brought into use if the heat pump is blocked for
any reason.
See also Lower tank Menu in the Detail Description Menus chapter
(Installer/Settings/Lower tank) and the DHW chapter.
4
1= 4

15
CTC EcoZenith i550 Pro
General Information
2.3.3 More Than One Heat Pump.
If more than one heat pump is installed, heat pumps two and three are
connected to the lower tank only.
Only one of the heat pumps alternates between DHW and heating operation.
The Ecozenith’s controller equalises the operating time between the heat
pumps so as to maximise heat output and minimise the load on them.
If the heat pump which starts first does not manage to get the temperature
up to the desired value, the second starts after a factory-set period of
30minutes, and then the third after another 30 minutes.
See also Heat pump Menu in the Detail Description Menus chapter
(Installer/Settings/Heat pump A1-A3)
2.3.4 Different Heat Pumps
The EcoZenith can control different types of heat pumps, the CTC EcoAir
(outdoor air heat pump) and the CTC EcoPart (bedrock/ground source
heat pump). The desired outdoor temperature at which the CTC EcoAir is
prioritised over the CTC EcoPart is set in the “Installer/Settings/Heat pumps
1, 2, 3” menu under “Prio EcoAir/EcoPart”. This means that the operating
economy can be maximised, as at a high outdoor temperature a greater
energy yield is obtained from the CTC EcoAir than from the CTC EcoPart.
This combination is excellent in installations where, for example, bedrock/
ground source heat pumps are designed with too much focus on “saving”
etc. An air/water heat pump may then be used to allow the bedrock more
time to “recover” and to provide increased output of the installation.
Remember that only one heat pump can be connected via the diverting
valves and charge hot water in the upper tank.
See also Heat pump Menu in the Detail Description Menus chapter
(Installer/Settings/Heat pump A1-A3)

16 CTC EcoZenith i550 Pro
General Information
2.3.5 Speed-controlled charge pump
(accessory from CTC)
Each heat pump should be provided with a separate charge pump that is
controlled in tandem with its respective heat pump. If a speed-controlled
PVM charge pump (accessory from CTC) is connected to the heat pump
and controlled from the EcoZenith, the flow will be automatically set without
any adjustment needed via the control valve. In the upper tank the speed of
the charge pump will be controlled so that the heat pump always delivers its
highest possible temperature into the top of the EcoZenith. This provides for
quick access to hot water when the heat pump starts.
Towards the lower tank the speed-controlled charge pump will work for a
fixed difference between flow and return from the heat pump.
If a speed-controlled charge pump is not installed, the flow has to be adjusted
manually, and the difference between incoming and outgoing water from the
heat pump will vary, depending on the operation conditions during the year.
In cases where an air/water heat pump is installed and the outdoor
temperature is less than +2°C, the charge pumps are started in order to
protect against frost. If a speed-controlled charge pump is installed, the pump
will only work at 25% of its maximum capacity. This provides for increased
savings on the charge pump’s operating economy, and the heat losses in the
EcoZenith are reduced compared to a conventional on/off charge pump.
See also Heat pump Menu in the Detail Description Menus chapter (Installer/
Settings/Heat pump A1-A3)
2.4 Wood Boiler
The EcoZenith can be connected to a wood boiler, such as the CTC V40.
Theprimary flow from the wood boiler is connected to the top of the
EcoZenith and the return flow to the wood boiler is connected to the lowest
connection on the lower tank.
When firing is started and the flue gas sensor reaches a set value (menu
“Installer/Settings/Wood boiler” factory-set “100°C”), the control goes into
wood operation status when the temperature of the lower tank is above or
equal to its reference value (setpoint). When wood operation is active, a heat
pump or additional heat are not used for heating the EcoZenith. When the flue
gas sensor is below the set value, wood operation status is interrupted.
It is recommended the wood boiler be provided with a charge system.
A charge system such as Laddomat 21 is recommended for optimum
performance. In special cases, such as operation with a water-jacketed stove,
the charge pump may be controlled from the EcoZenith without installing a
charge system.
See also Wood Boiler Menu in the Detail Description Menus chapter
(Installer/Settings/Wood boiler)

17
CTC EcoZenith i550 Pro
General Information
2.5 Additional boiler (pellets, oil, gas,
electricity)
The EcoZenith can control an external additional boiler (pellets, oil, gas,
electricity). The additional boiler is connected to the upper tank. Use the
menu to select whether the external additional boiler should have high or low
priority. If high priority is selected, the external additional boiler is activated
before the immersion heater(s); when low priority is selected, the immersion
heater(s) is/are activated first.
After a certain delay, which is factory set at 120 minutes, the unit with low
priority is also started and helps the heat source with high priority.
The EcoZenith handles start and stop of the charge pump between the
external boiler and the EcoZenith.
The charge pump starts once the upper tank’s temperature has dropped
to 60°C and stops once the temperature has reached 65°C. A shorter
operating time may be set to ensure the external boiler is in operation even if
the charge pump is switched off.
See also External Boiler Menu in the Detail Description Menus chapter
(Installer/Settings/Ext boiler)

18 CTC EcoZenith i550 Pro
General Information
illustration 2
illustration 1
2.6 Solar Energy
The EcoZenith contains a 10 m long 18 mm finned and internally grooved
solar coil which manages approx. 10 m² of solar panel. On larger solar panel
installations, the solar energy is connected via an external heat exchanger
(see figure 2). The heat exchanger is connected to the upper and lower
connections on the lower part of the CTC EcoZenith (either side is possible).
If a greater number of panels is connected, one or more buffer tanks can
also be installed in the system. More information on function and control of
buffer tanks can be found in the Extra Buffer Tank section.
If the solar panels produce a temperature which is more than 7 degrees
(factory-set) higher that the sensor (B32/B33), the charge pump starts and
transfers the solar energy to the lower tank. The speed-controlled PVM
pump controls the flow so that it always delivers a temperature which is
7°C higher. This means that if solar panel output rises, the charge pump will
increase the flow, and if solar panel output decreases, the charge pump will
reduce the flow. When the temperature in the lower tank increases or the
solar panel loses temperature, and the difference between the temperature in
the solar panel and the lower tank is below 3 degrees (adjustable), charging
stops. Charging will not restart until the solar panel is again 7 degrees
warmer than the lower tank.
When the temperature in the lower tank rises and becomes warmer than
the upper tank, by the laws of physics, heat will rise into the heat distribution
pipe and layer itself into the right temperature level in the upper tank
through perforated holes in the distribution pipes. The colder temperature
in the upper tank will, in the same way, sink down and distribute itself in
its temperature zone in the lower tank through the distribution pipe which
descends into the lower tank. Based on the factory setting, the sun will heat
the lower tank in the EcoZenith to 85°C before the charging is stopped.
See also Solar Panels Menu in the Detail Description Menus chapter
(Installer/Settings/Solar panels)

19
CTC EcoZenith i550 Pro
General Information
2.7 Recharging Bedrock/Ground
If a liquid-water heat pump is connected, a diverting valve can be installed
on the solar circuit and connected to the brine circuit (the loop in the bore
hole or the ground heat loop) to recharge the bedrock/ground when the
EcoZenith is fully charged (factory set 85°C), or when the temperature in the
solar panel is not sufficiently warm to charge the EcoZenith, but can provide
an addition to the brine circuit.
The solar panel temperature should be factory set at 60°C warmer than the
brine temperature in order for charging to start. When the difference between
the temperature in the solar panel and the brine circuit falls to 30°C, charging
is stopped. If the brine circuit becomes warmer than the factory-set value of
18°C, recharging will also be interrupted, as the temperature then becomes
too high for the heat pump to work.
When the solar energy system works towards the brine circuit, the flow is
factory set to switch every thirty minutes to the EcoZenith to check whether
charging is possible, as the EcoZenith always has the highest priority. If
possible, charging towards the EcoZenith will continue. Otherwise charging
reverts to the brine circuit. Safety measures for the collector/solar system are
available.
See also Protection Collector Menu in the Detail Description Menus
chapter (“Installer/Settings/Solar panels/Protection collector”) and also
Winter Mode Menu in the Detail Description Menus chapter (“Installer/
Settings/Solar panels/Winter mode”)

20 CTC EcoZenith i550 Pro
General Information
2.8 External Hot Water Tank
An external water heater can be connected to the EcoZenith. This results
in a greater stored hot water volume, which contributes to higher hot water
capacity.
The incoming cold water first passes through the EcoZenith where it is
heated before it flows into the hot water tank and out to the property’s taps.
This means that, when the temperature from the EcoZenith is no longer
sufficient, the entire volume of the hot water tank is still there to be used.
When the temperature in the upper tank of the EcoZenith is factory set 5°C
warmer than in the external hot water tank, the charge pump starts. The
heat from the upper tank charges the hot water tank until the increase in
temperature in the latter does not exceed one degree per three minutes.
When hot water is stored below 60°C, heating of the hot water tank at
regular intervals is necessary to eliminate the risk of Legionella. This function
is built into the EcoZenith. First the upper tank is heated as far as possible
using the heat pump. For the water heater to reach 65°C during 1 hour, the
immersion heater is allowed to engage to raise the temperature over the final
degrees. The factory setting for this is every fourteen days.
See also Upper tank Menu in the Detail Description Menus chapter
(Installer/Settings/Upper tank)
2.9 Pool
A pool is connected to the EcoZenith’s lower tank. Between the EcoZenith and
the pool, a heat exchanger is installed to separate the liquids.
A sensor in the pool starts and stops the pool’s charge pumps in order
to maintain the set temperature in the pool (factory set at 22°C), and the
temperature is allowed to fall by one degree before the charge pump
starts again. It is also possible to set the pool priority to high or low, which
determines whether or not additional heat can be used for heating the pool.
See also Pool Menu in the Detail Description Menus chapter
(Installer/Settings/Pool)

21
CTC EcoZenith i550 Pro
General Information
2.10 External Buffer Tank
The EcoZenith can be connected to one or more buffer tanks. This is mainly
used when connecting wood and solar energy systems where the volume in
the EcoZenith is not sufficient. Via the accessory “Charging External Storage
Tank”, warm water can be sent both from the lower tank to the buffer tank(s)
and from the buffer tank(s) back to the EcoZenith. In other words, both
charging and recharging of the energy are possible.
See also External Storage Tank Menu in the Detail Description Menus
chapter (Installer/Settings/Ext storage tank) and HP Charging Menu in
the Detail Description Menus chapter (Installer/Settings/Ext storage
tank/HP charging).
2.10.1 Solar Operation Control
When solar energy is activated, the transfer to the buffer tank(s) is performed
in two ways depending on whether heating is needed for the heating system.
When heating is not needed for the heating system, the sun charges the
EcoZenith in order to achieve a high temperature and a large quantity of
hot water. The solar panels charge the EcoZenith until the sensor of the
lower tank reaches the factory-set 80°C before the circulating pump starts
up and transfers hot water from the EcoZenith connection in the lower tank
into the top of the first buffer tank. Charging continues until the sensor in
the lower tank has fallen 3 degrees (transfer starts at 80 degrees and stops
at 77 degrees). The lower tank must be at least 7 degrees warmer than the
buffer tank for charging to be allowed to start. This applies independently of
whether there is a need for heating or not.
When there is a need to heat the house, the transfer will be controlled by
the reference value (setpoint) in the lower tank. When the sun has heated
the lower tank to 7 degrees above the reference value, the transfer starts,
provided that the lower tank is also 7 degrees warmer than the buffer tank.
Efficiency of the solar panels increases when they work towards a low water
temperature, which is the case in spring and autumn, as there is no great
need for heating during either of these seasons. The temperature levels
stated above can be adjusted.

22 CTC EcoZenith i550 Pro
General Information
2.10.2 Wood Operation Control
The wood boiler charges the EcoZenith until the sensor of the lower tank
reaches the factory-set 80°C, before the charge pump starts up and
transfers hot water from the lower tank into the top of the first buffer tank.
Charging continues until the sensor in the lower tank has fallen 3 degrees
(transfer starts at 80 degrees and stops at 77 degrees). The lower tank must
be at least 7 degrees warmer than the buffer tank for charging to be allowed
to start, based on the factory-set values.
2.10.3 Recharging from Buffer Tank to EcoZenith
Recharging from Buffer Tank to the EcoZenith is always performed to the
upper tank, if possible. If charging to the EcoZenith’s upper tank is not
possible due to too low a temperature difference, the controller checks if
charging to the lower tank is possible. The condition for recharging is a
7degree temperature difference.
Charging from the buffer tank to both the upper and the lower tanks in
the EcoZenith is stopped when the temperature difference has fallen to
a difference of 3 degrees. The temperature levels stated above can be
adjusted.