Cetetherm Mini Plus CM737
Installation, service and operating instruction
5
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.
Mini Plus has automatic temperature control for heating and hot water. The heating circuit is controlled in
relation to outdoor temperature and/or desired room temperature by means of a controller and temperature
sensor. When no heat is needed, the circulation pump in the heating circuit stops automatically, but is started
regularly to make sure that it does not seize up during long idle periods.
The hot water temperature is controlled by a temperature control system which is set to about 55 ºC.
After adjustment, the Mini Plus 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 variation 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.
The heating system is topped up via the heating filler valves, see
15.2 Heating system service instructions
. Be
sure to close the valves 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 a year, when the heating system has been thoroughly bled and balanced.
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.
For setting and (if necessary) fine adjustment of the heating and hot water temperatures, see
chapter 8.
