Danfoss EvoFlat Four Pipe System Montage- Und Betriebsanleitung Seite 24

User manual
13. TROUBLESHOOTING GENERAL
In the event of operating disturbances, the following basic features
should be checked before carrying out actual troubleshooting:
• the flat station is connected to electricity,
• the strainer on the HS supply pipe is clean,
• the supply temperature of the HS is at the normal level,
• the differential pressure is equal to or higher than the normal
(local) differential pressure in the HS network – if in doubt, ask
the HS plant supervisor.
Problem
Too little or no DHW.
Hot water in some taps but not in all.
Tap temperature too high; DHW tap load
too high.
Temperature drop during tapping.
24 | © Danfoss | Produced by Danfoss Redan A/S | 2020.06
EvoFlat Four-Pipe System
/ TROUBLESHOOTING DHW
Possible cause
Strainer in supply or return line clogged.
DHW circulation pump out of order or with
too low setting. (only if DHW circulation
is installed).
Defective or clogged non-return valve.
No electricity. Only if station are with DHW
circulation.
Scaling of the plate heat exchanger.
Defective temperature sensors.
Defective controller.
DCW is being mixed with the DHW, e.g. in
a defective thermostatic mixing valve.
DHW circulation pump out of order or with
too low setting. (only if DHW circulation
is installed).
Thermostatic valve adjusted to a too high
level. Thermostat is defect.
Scaling of the plate heat exchanger.
Larger DHW flow than the flat station has
been designed for.
Authorized personnel only
Assembly, start-up and maintenance work must be per-
formed by qualified and authorized personnel only.
Solution
Clean strainer(s).
Check circulation pump.
Replace – clean.
Check.
Replace – rinse out.
Check – replace.
Check – replace.
Check – replace.
Replace – clean.
Check – set – replace.
Replace – rinse out.
Reduce DHW flow.