Cetetherm Mini Plus CM737
Installation, service and operating instruction
35
Reason
Action
Air pockets in the substation or in the
heating circuit
Bleed the heating system
Bleed the heating system at highest point in the heating system.
The pump is self-venting. Air in the pump may cause noise. This
noise ceases after a few minutes run time.
Bleed the radiators.
Picture 18
Heating supply temperature sensor and
outdoor temperature sensor does not
work
Check the heating supply temperature sensor and outdoor
temperature sensor
Check that they are correctly sited and working. To confirm that
sensors are connected and operating, press the info button on the
operator control panel, check that the specified temperatures are
reasonable.
Loss of function in the heating control
unit.
Heating circuit filter clogged
See
17.2 Cleaning the heating circuit filter
15.2.3 Heating system often needs topping up
Reason
Action
Leaks in the substation or in the system
Check the substation and the system for leaks
Leaks from the substation or the heating system cause pressure
drop.
Contact your service technician if finding any leaks.
The heating system safety valve is
leaking or does not work
Check the heating system safety valve
Check that the heating system safety valve is not leaking and that
it works properly. Check the safety valves’ function by turning the
red wheel/knob until water runs out of the valve’s waste pipe and
then close the valve quickly.
The expansion vessel cannot handle
the changes in the system
See
16.5 Check the volume take-up and pressure equalizing of the
15.2.4 Heating temperature unstable
Reason
Action
Alternating pressure on primary side
Check available differential pressure and temperature at the
district heating medium supply.
District heating filter clogged
See
17.1 Cleaning the district heating filter .
Heating supply temperature sensor and
outdoor temperature sensor does not
work
Check the heating supply temperature sensor and outdoor
temperature sensor
Check that they are correctly sited and working. To confirm that
sensors are connected and operating, press the info button on the
operator control panel, check that the specified temperatures are
reasonable.
