Technical data

8
CTC EcoZenith i250
General Information
1. Your home's heating installation
Your home's heating installation
!
The set heating curve is always given priority. The room sensor can only increase
or decrease the compensated flow temperature to a certain extent above the set
heating curve. Where operating without a room sensor, the selected heating curve
determines the flow temperature supplied to the radiators purely from the outside
temperature reading.
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.
• 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.
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