Montage- und Betriebsanleitung / User manual
VXe SLS
© Danfoss | Produced by Danfoss Redan A/S | 2022.03 | 29
AQ40514397064001-000101
145X2068
Maintenance work
Is only to be carried out by qualified and authorised personnel.
Inspection
The water heater should be checked regularly by authorised personnel. 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 temperature 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.
14. MAINTENANCE
Authorized personnel only
Assembly, start-up and maintenance work must be per-
formed by qualified and authorized personnel only.
