B
C
A1
D
A2
T-piece
13
13
Instructions for installation and use
TD & S substations
Danfoss District Energy
VI.GP.U2.02
DKDHR
12. Installation instructions, recirculation connection
Systems with domestic hot water recirculation
If the household piping system features domestic hot water recircula-
tion, the substation
must
be connected to the recirculation system.
The circulation set for recirculation connection is not standard equip-
ment. The set must be purchased as extra equipment.
We recommend establishing recirculation BEFORE mounting
the substation on the wall.
Connect the recirculation pipe from the fixed household piping
system to the hexagon nipple at the bottom of the substation (see
the bottom of the page for instructions about how to make the re-
circulation connection).
You
must always fit a pump and non-return valve
to the circulation
pipe, with flow direction in towards the substation.
If a time-controlled pump is used, we recommend setting the circula-
tion water temperature to approx. 35°C.
Please note that if the circulation pump (outside the substation) is
stopped for a protracted period, we recommend shutting off the
by-pass thermostat for the same period.
NB!
Please note that substations fitted with Danfoss AVE expansion units
must
not
be used on systems with DHW recirculation.
The photo to the right presents an Akva Lux II S substation, but in prin-
ciple, the recirculation connection procedure can be carried out in the
same way, regardless of substation type.
Fig. 1
Remove the existing capillary tube between the bypass thermo-
stat and the T-piece (see top photo). NB! The capillary tube may be
mounted in front of the T-piece on TD substations!
Fig. 2
Remove the nipples/plugs from the domestic hot water controller
(use a 6 mm Allen key). Do not re-use the plugs!
Fig. 3
Fit/screw hose end (A1) onto the controller and fit the pipe bushing
(B) in the controller.
Fig. 4
Use a conical screw plug (C) to seal off the T-piece.
Fig. 5
Fit a new capillary tube (E) (incl. cutting rings and union nut, F1 and
F2) between the bypass valve and pipe bushing B.
Fig. 6
Fit hose end (A2) and hexagon nipple (D) through the mounting
rail at the bottom (and finish off by connecting the household
recirculation pipe to the hexagon nipple D).
Fig. 1
Fig. 3
Fig. 5
Fig. 2
Fig. 4
Fig. 6
F1
B
F2
D
C
E
A1
A2
