Instructions
DH-SMT/PL
VI.KR.Z1.02 ©
Danfoss 09/2006
9
Akva Vita TDP-F - district heating flat station for direct HE and DHW
Troubleshooting
HE
If operating disturbances occur, the following basic
features should be checked before carrying out
actual troubleshooting:
- the substation is connected to electricity
(applies only to substations with room
thermostat),
- the strainer on the district heating supply pipe
is clean,
- the supply temperature of the district heating
is at the normal level (summer, at least 60 °C
- winter, at least 70 °C),
- the differential pressure is higher than or equal
to the normal (local) differential pressure in the
district heating network – if in doubt, ask the
district heating plant,
- there is pressure on the system.
Problem
Possible cause
Solution
No heat
Strainer clogged on DH or HE side
(radiator circuit).
Filter in the district heating meter
clogged.
Defective or wrongly adjusted
differential pressure controller.
Defective room thermostat/actuator
- or possibly dirt in the zone valve
housing.
Air pockets in the system.
Clean gate/strainer.
Clean the filter (after
consulting the district
heating plant).
Check the operation of the
differential pressure
controller – clean the valve
seat if required.
Check the operation of the
room thermostat/actuator
- clean the zone valve seat if
required.
Air the installation
thoroughly.
Uneven heat
distribution
Air pockets in the system.
Air the installation
thoroughly
Supply temperature
too low
Strainer clogged.
Clean gate/strainer.
Poor cooling
Too small heating surface/too small
radiators in relation to the total
heating requirement of the building.
Poor utilization of existing heating
surface.
The system is single-pipe.
Increase total heating
surface.
Make sure the heat is
distributed evenly across
the full heating surface. It
is recommended to avoid
fully opened thermostats
on some radiators and fully
shut-off thermostats on
others. Higher temperature
at the top and lower
temperature at the bottom
part of radiators means that
the system operation is
correct.
It is extremely important to
keep the flow temperature to
the radiators as low as ever
possible, while maintaining a
reasonable level of comfort.
