Instructions for installation and use
Akva Lux II VXe
© Danfoss | Produced by Danfoss Redan A/S | 2021.02 | 21
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Maintenance work
Is only to be carried out by qualified and authorised personnel.
Inspection
The water heater should be checked regularly by authorised person-
nel. Any necessary maintenance must be performed in accordance
with the instructions in this manual and other sets of instructions.
During service the dirt strainers are to be cleaned – including the
filter on the controller, all pipe connections must be tightened and
the safety valve must be function tested by turning the lever.
Rinsing/cleaning of plate heat exchanger
To clean the plate heat exchanger, rinse it by running clean water
through the exchanger at high speed and in the opposite direction
to the normal flow. This will remove any dirt deposits that may have
built up in the exchanger. If rinsing with clean water is not sufficient,
the exchanger can also be cleaned by circulating a cleaning agent
approved by Danfoss (e.g. Kaloxi or Radiner Fl cleaning fluid) through
the exchanger. Both these cleaning fluids are environmentally friendly
and can be disposed off through the standard sewer system. After
use of a cleaning fluid, the plate heat exchanger must be rinsed
thoroughly with clean water.
Acidification of brazed plate heat exchanger
As a starting point, we do not recommend acidification of the
exchanger. Deposits of limescale may build up in plate heat exchangers
for domestic hot water on account of the large temperature
fluctuations, and because aerated water is used on the secondary
side. If it becomes necessary to clean the exchanger with acid, this
can be done as shown on the drawing to the right. Brazed plate heat
exchangers can withstand rinsing with a dilute acid solution - e.g.
5% formic, acetic or phosphoric acid).
Measures after maintenance work
After maintenance work and before commissioning:
– Check that all screwed connections are tight.
– Check that all safety features, covers, that were removed, have
been replaced properly.
– Clean the working area and remove any spilled materials.
– Clear all tools, materials and other equipment from the working
area.
– Connect to energy supply and check for leaks.
– Vent the system.
– Carry out any necessary adjustment again.
– Make sure that all safety features on the device and the system
work properly.
Meter reading
The caretaker/owner must perform visual checking and reading of
the district heating meter at short, regular intervals. (The meter is
not a part of the delivery from Danfoss).
Service procedures must only be performed by trained, authorised
personnel.
NB! Excessive consumption for whatever reason is not covered by
the Danfoss warranty.
Cooling / Return temperature reading
Cooling – i.e. the difference between the supply and return tempera-
ture of the district heating water – has a significant effect on overall
energy economy. Therefore, it is important to focus on the supply
and return temperature in the heating system. The difference should
typically be 30–35°C. Please note that a low district heating return
temperature is directly related to the return temperature from the
heating circuit and the return temperature of the circulation water.
It is therefore important to focus on these return temperatures.
15. MAINTENANCE
