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Danfoss District Energy
VI.GP.N2.02
DKDHR
Instructions Water
Heaters
13.0 Akva Vita II - Instructions
13.1 General
PLEASE NOTE that your water heater may look different than the wa-
ter heater shown, as variants with other components may be supplied.
The control function, however, is basically as decribed below.
Maintenance and setting
The cover can be removed without using tools. For cleaning of plate
heat exchanger see page 17.
13.2 Description
The water heater is based on a brazed plate heat exchanger. The
domestic hot water temperature is controlled by a hydraulic self-acting
controller PM2+P controller with integrated differential pressure control-
ler, which blocks the flow of primary and secondary side flow through
the heat exchanger immediately after completion of the tapping process.
13.3 DHW temperature control
Danfoss PM2+P controller (1) for DHW. The DHW temperature is adjusted
by turning the lever towards the red (warmer) or blue (colder) mark.
Start by turning the handle clockwise - until the temperature indica-
tor is exactly opposite the blue dot. Then turn the handle
counter-
clockwise
until the temperature of the tap water is approx. 48 ° C at
normal use (7-8 l/min). The temperature should never exceed 55 ° C to
avoid lime scale precipitation.
(NOTE! The temperature indicator must be between the blue and the
red dot, otherwise the controller will close.
13.4 By-pass or circulation thermostat
Bypass thermostat (default).
As a standard the Akva Vita II is equipped with a bypass thermostat,
Danfoss FJVR (2), which ensures that hot water is produced immedia-
tely, when tapping starts. It is recommended to set the thermostat in
pos.3. If the water temperature rises too slowly it can be necessary to
set the thermostat at higher value.
Alternatively a DHW circulation system must be installed.
Circulation thermostat / control change to circulation.
If the water heater is connected to the DHW recirculation system in the
building, the FJVR thermostat (3) will function as a circulation thermostat
and control the circulation water temperature, independently of the set
DHW temperature. It is recommended to set the thermostat in pos 3.
For circulation connection please refer to page 11 and 12.
The photo to the right shows a water heater, on which circulation hose
and capillary tube have been mounted and connected to the domestic
hot water controller, enabling the temperature of the circulating water
13.5 Akva Vita II with Danfoss AVE
The AVE expansion unit absorbs the thermal expansion of water in the
heat exchanger. A discharge pipe is not necessary.
For mounting of AVE on site remove the brass angle and replace with a
T-piece, a non-return valve and the AVE as shown. (Insert the T-piece in
the hole in the mounting plate and mount the 3/4” x 1/2”union piece
on the T-piece - do not forget to include gaskets)
The AVE expansion unit must not be applied to systems with domestic
hot water recirculation.
For systems with DHW circulation the expansion
unit must be replaced by a safety valve and a discharge pipe, which is
piped directly into the floor drain, must be installed.
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Temperature indicator
