Cetetherm Mini Plus CM737, Installation, Service And Operating Instruction

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Cetetherm Mini Plus CM737
Installation, service and operating instruction
32
15
Service instructions
To avoid the risk of scalding, make sure that no-one draws any water while servicing the
substation.
Grey marked service actions must be carried out by an authorized service technician.
Note! Make sure that the Mini Plus had been correctly installed.
15.1 Tap water service instructions
15.1.1 Tap water temperature too low
Reason Action
District heating supply too low Check the primary inlet temperature
The temperature can be checked by means of the energy meter (min 65º
C) or at the district heating medium supply.
Handle on control valve
incorrectly positioned Adjust the handle on the control valve
The hot water temperature can be controlled by turning the handle, on
the control valve for domestic hot water, counter clockwise for increased
tap water temperature. To decrease tap water temperature, turn the
handle clockwise, until the desired tap water temperature is reached (55º
C approx.). The stabilisation time for the hot water temperature is about
20 seconds.
District heating filter clogged See 17.1 Cleaning the district heating filter
Hot water valve does not work See 16.1 Check the function of the valve for hot water .
Balancing valve DHWC may
need to be adjusted Check and adjust the DHWC balancing valve
Check that the balancing valve is open enough
15.1.2 Tap water temperature too high
Reason Action
Handle on control valve
incorrectly positioned Adjust the handle on the control valve
The hot water temperature can be controlled by turning the handle, on
the control valve for domestic hot water, counter clockwise for increased
tap water temperature. To decrease tap water temperature, turn the
handle clockwise, until the desired tap water temperature is reached (55º
C approx.). The stabilisation time for the hot water temperature is about
20 seconds.
Hot water valve and/or actuator
does not work Check the valve according to
16.1 Check the function of the valve for hot water .
If the water temperature is too high when the handle is in position 0, the
actuator or the exchanger is damaged and requires replacing.
15.1.3 Hot water 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
DHWC pump is not running Check that the electrical power is on
If the pump fails to start after stopping, try to start it at the highest
setting.
See
16.3 Check the circulation pump Grundfos UPS.
Balancing valve DHWC may
need to be adjusted Check and adjust the DHWC balancing valve
Check that the balancing valve is open enough
Check valve DHWC is damaged Check and change if required, see 17.11 Change the DHWC check
valve .