Installation Guide
Termix VMTD Compact 20
7.0 Troubleshooting
7.1 Troubleshooting in general
In the event of operating disturbances, the following basic features
should be checked before carrying out actual troubleshooting:
•
the substation is connected to electricity,
•
the strainer on the DH supply pipe is clean,
•
the supply temperature of the DH is at the normal level
(summer, at least 60 °C - winter, at least 70 °C),
•
the differential pressure is equal to or higher than the normal
(local) differential pressure in the DH network – if in doubt, ask
the DH plant supervisor,
•
pressure on the system - check the HE pressure gauge.
Authorized personnel only
Assembly, start-up and maintenance work must be performed by
qualified and authorized personnel only.
7.2 Troubleshooting DHW
Problem
Possible cause
Solution
Strainer in supply or return line clogged.
Clean strainer(s).
DHW circulation pump out of order or with
too low setting.
Check circulation pump.
Defective or clogged non-return valve.
Replace – clean.
No electricity.
Check.
Wrong setting of automatic controls, if any.
To adjust an electronic controller for
DHW, pls. note enclosed instructions for
electronic controller.
Scaling of the plate heat exchanger.
Replace – rinse out.
Defective motorized valve.
Check (use manual function) – replace.
Defective temperature sensors.
Check – replace.
Too little or no DHW.
Defective controller.
Check – replace.
DCW is being mixed with the DHW, e.g. in
a defective thermostatic mixing valve.
Check – replace.
Hot water in some taps but not in all.
Defective or clogged non-return valve on
circulation valve.
Replace – clean.
Tap temperature too high; DHW tap load
too high.
Thermostatic valve adjusted to a too high
level.
Check – set.
Scaling of the plate heat exchanger.
Replace – rinse out.
Temperature drop during tapping.
Larger DHW flow than the substation has
been designed for.
Reduce DHW flow.
Thermostatic control valve does not close
Temperature difference between DH
supply and DHW set point too low.
Lower the set point temperature or
increase the DH supply temperature.
18
DEN-GT
VI.CW.W2.02 / LUK41200
Danfoss Heating
Summary of Contents for Termix VMTD Compact 20
Page 2: ...Installation Guide Termix VMTD Compact 20 2 DEN GT VI CW W2 02 LUK41200 Danfoss Heating...
Page 21: ...Installation Guide Termix VMTD Compact 20 Danfoss Heating VI CW W2 02 LUK41200 DEN GT 21...
Page 22: ...Installation Guide Termix VMTD Compact 20 22 DEN GT VI CW W2 02 LUK41200 Danfoss Heating...
Page 24: ...Installation Guide Termix VMTD Compact 20 Produced by Danfoss A S 01 2012...
