Instructions for installation and use
Akva Lux II VXe
20 | © Danfoss | Produced by Danfoss Redan A/S | 2021.02
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14. DOMESTIC HOT WATER
General information
PLEASE NOTE! Some models may have a slightly different appearance,
but the control function is in principle the same as described below.
Commissioning
Commission the substation in accordance with the instructions in
this manual.
Regulation of domestic hot water temperature
The domestic hot water is prepared in the heat exchanger based on
the flow principle and the temperature is controlled by a combined
hydraulic and thermostatic self-acting controller
PTC2+P
with in-
tegrated differential pressure controller, which blocks the flow of
primary and secondary side flow through the heat exchanger im-
mediately after completion of the tapping process.
PTC2 controller for DHW (Fig. 1).
Adjust the hot water temperature by moving the adjuster lever to-
wards “+” (hotter) or “-” (colder). Start by turning the lever clockwise
– until it stops/until you cannot turn it any further. Then turn the lever
counter-clockwise until the temperature of the tap water is approx.
48°C during normal tapping flow (7–8 litres per min.). The temperature
must never exceed 55°C to prevent limescale deposits building up
in the water heater.
Bypass thermostat (default)
As a standard the substation is equipped with a bypass thermostat,
Danfoss FJVR, so that when water is tapped, the water heater
immediately starts to produce hot water. We recommend setting
of the thermostat in pos.3. If you have to wait a long time (i.e. more
than 20 sec.) for hot water, it may be necessary to set the thermostat
at a higher value.
If you want to avoid waiting time altogether, you will need to set up
domestic hot water recirculation to the tapping points.
Circulations thermostat / conversion to recirculation
If the household piping system features domestic hot water recir-
culation, the substation must be connected to the recirculation sys-
tem.
Scale setting (indicative)
Pos. 2 = 30°C
3 = 40°C
4 = 45°C
Conversion to recirculation requires only an additional circulation
set. (This is not part of the delivery and must be purchased as extra
equipment, - see photo on page 14).
Connect the recirculation pipe from the fixed household piping sys-
tem to the hexagon nipple at the bottom of the substation (please see
page 14 for instructions about how to make recirculation connection).
If a time-controlled pump is used, we recommend setting the circu-
lation water temperature to approx. 35 °C.
Alternative controller PM2+P
As alternative the temperature can be controlled by a the pres-
sure-controlled self-acting controller PM2+P with integrated differ-
ential pressure controller. Set the DHW temperature by turning the
adjuster lever towards red (hotter) or blue (colder). Start by turning
the lever clockwise - until the pin is opposite the blue dot. Then turn
the lever counter-clockwise until the temperature of the tap water
is approx. 48°C during normal tapping flow (7–8 litres per min.). The
temperature must never exceed 55°C to prevent limescale deposits
building up in the water heater. NB! The pin must be positioned be-
tween the blue and red dot, otherwise the controller will shut down.
Abb.
Adjuster lever
Adjuster lever
Fig. 1
Fig. 2
Fig. 3
