Technical data
5  CTC EcoZenith i250
General Information
General Information
Congratulations on buying your new product
You have just bought a CTC EcoZenith i250, which 
we hope you will be very pleased with. In the following 
pages you can read about how to operate and maintain 
your boiler. One chapter is written for the property 
owner and one chapter for the installer. 
Keep 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 
i250 for many years. This manual will provide all the 
information you will need.
The complete system tank
The CTC EcoZenith i250 is a complete system tank 
which meets your home’s heating and hot water 
requirements. It has a built-in immersion heater giving a 
total of 15 kW and is equipped with a motorised mixing 
valve which ensures correct and even temperatures are 
supplied to your heating system. The CTC EcoZenith 
i250 has a built-in circulation pump for connection to a 
heat pump. 
The CTC EcoZenith i250 is fully designed to work with 
the CTC EcoAir 406-410 outdoor air heat pump or 
CTC EcoPart 406-410 bedrock/ground source heat 
pump. CTC EcoPart 412 can also be connected to the 
EcoZenith i250 provided that the function "exact primary 
flow" is activated. All controls for the heat pump and 
charge pump are built into the CTC EcoZenith i250. 
With this added feature you achieve a very eco-friendly 
and energy-saving heating system.
For more information, please see the separate section in 
this manual.
The CTC EcoZenith i250 has a control 
system that:
•  Monitors all system tank, heat pump and heating 
system functions
•  Permits individual settings
•  Displays desired values, such as temperatures, 
operation times, energy consumption and fault 
signals
•  Facilitates the setting of values and troubleshooting 
in a simple and well-structured way
The built-in copper coil provides copious amounts of 
hot water. The CTC EcoZenith i250 also has a so-
called summer-time basement heating function and a 
floor heating block, which maximises the temperature 
supplied to the floor circuits. Using the integrated 
night reduction function, you can set and change the 
temperature in the house during the day, from one day 
to the next.
Easily accessible electrical components, along with 
effective troubleshooting functions in the control 
program, make the CTC EcoZenith i250 easy to service. 
It comes with a room sensor as standard, which is 
equipped with an LED which flashes in the event of a 
fault.
If you want to supplement your CTC EcoZenith i250 
with other heating, you can do this easily thanks to two 
unique connections. We have decided to call this option 
Energyflex. With Energyflex you can, for example: 
•  Charge your heating system with solar energy
•  Allow a water-jacketed stove to contribute heat
•  Connect a pool exchanger to heat up a swimming 
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