Instructions
DEN-GT
VI.CW.C1.02 / LUK40110 © Danfoss 04/2011
9
Termix VMTD-F-B - substation for direct HE and DHW
Troubleshooting DHW
We recommend that troubleshooting be carried
out only by authorized personnel.
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.
Problem Possible cause Solution
Too little or no DHW
Strainer in supply or return line clogged. Clean strainer(s).
DHW circulation pump out of order or
with setting too low.
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.
Defective controller. Check – replace.
Hot water in some taps but
not in all.
DCW is being mixed with the DHW, e.g.
in a defective thermostatic mixing valve
or non
Check – replace.
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
Temperature drop during
tapping.
Scaling of the plate heat exchanger. Replace – rinse out.
Larger DHW flow than the substation
has been designed for.
Reduce DHW flow.
To Next Page
Loading...
Need help?
General
