15
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Instructions for installation and use
S 22
Danfoss District Energy
VI.IE.D1.02
DKDHR
Problem
Possible cause
Solution
DHW*,
variations in temperature
Non-return valve in the circulation pipe
defective (leads to mixing - the circula-
tion water pipes become cold during
tapping).
Replace the non-return valve.
Temperature too low / variations in
temperature
Non-return valve in thermostatic mixer
in the bathroom defective - results in hot
and cold water mixing. Please note that
fluctuating temperatures may occur at
other tapping points in the system!
NB, Check all mixers in the house for
faults/defects!
Replace the mixer or perhaps only the
non-return valve.
Lack of hot water pressure
Clogged strainer in the cold water meter
or possibly in the cold water supply in
the unit.
Calified heat exchanger
Clean the strainer (cold water meter,
in consultation with the water supply
company).
Replace the heat exchanger.
Long wait for hot water
Circulation pump out of order.
Check whether the pump is running -
and whether there is a power supply to
the pump. Make sure that there is no air
in the pump housing.
No hot water
Dirt strainer in the district heating sup-
ply line clogged.
Defective controller.
Defective sensor.
Clean the dirt strainer.
Check controller settings. You may con-
tact Danfoss Redan A/S for further infor-
mation.
Replace sensor.
Hot water temperature too low
As above.
Non-return valve in the circulation pipe
defective (leads to mixing - the circula-
tion water pipes become cold during
As above.
Replace non-return valve.
Hot water temperature too high
Defective automatics/controller.
Check controller settings. You may con-
tact Danfoss Redan A/S for further infor-
mation.
Temperature falls during tapping
(lack of capacity)
Air in the capillary tube for the differen-
tial pressure controller.
Calified plate heat exchanger.
Vent the capillary tube.
Replace the plate heat exchanger
