Cleaning / Maintenance; Maintenance; Cleaning The Heating System; Cleaning The Heat Source System - Dimplex WI 65TU Installation And Operating Instruction

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9

Cleaning / maintenance

9.1 Maintenance

To prevent faults due to sediment in the heat exchangers, care
must be taken to ensure that no impurities can enter either the
heat source system or the heating system. In the event that op-
erating malfunctions due to contamination occur nevertheless,
the system should be cleaned as described below.

9.2 Cleaning the heating system

The ingress of oxygen into the heating water circuit may result in
the formation of oxidation products (rust), particularly if steel
components are used. These enter the heating system via the
valves, the circulating pumps and/or plastic pipes. A diffusion-re-
sistant installation is therefore essential, especially with regard to
the piping of underfloor heating systems.
NOTE
We recommend the installation of a suitable corrosion protection system
to prevent the formation of deposits (e.g. rust) in the condenser of the
heat pump.
Residue from lubricants and sealants may also contaminate the
heating water.
In the event of severe contamination leading to a reduction in the
performance of the liquefier in the heat pump, the system must
be cleaned by a heating technician.
Based on current information, we recommend using a 5 % phos-
phoric acid solution for cleaning purposes. However, if cleaning
needs to be performed more frequently, a 5 % formic acid solu-
tion should be used.
In both cases, the cleaning fluid should be at room temperature.
We recommend flushing the heat exchanger in the direction op-
posite to the normal flow direction.
To prevent acidic cleaning agents from entering the heating sys-
tem circuit, we recommend connecting the flushing device di-
rectly to the flow and return of the liquefier of the heat pump.
It is then important that the system be thoroughly flushed using
appropriate neutralising agents to prevent any damage from
being caused by cleaning agent residue remaining in the system.
Acids must be used with care and the regulations of the employ-
ers liability insurance associations must be adhered to.
The instructions of the cleaning agent manufacturer must always
be observed.
9.3 Cleaning the heat source
system
ATTENTION!
The supplied dirt trap must be inserted in the heat source inlet of the heat
pump to protect the evaporator against the ingress of impurities.
The filter sieve of the dirt trap should be cleaned one day after
start-up. Further checks must be set according to the level of dirt.
If no more signs of contamination are evident, the filter can be re-
moved to reduce pressure drops.
EN-10

9.4 Water quality requirements

Irrespective of any legal regulations, the ground water should not
contain any substances that could form deposits. Iron (< 0.2 mg/
l) and Manganese (< 0.1 mg/l) limit values must be adhered to to
prevent iron ochre sedimentation from forming in the heat source
system.
The use of surface water or water containing salt is not permissi-
ble. Your local water utility can provide you with general informa-
tion regarding the possible use of ground water. Water analyses
are carried out by specially-equipped laboratories.
Irrespective of any legal regulations, a water analysis must be
carried out to establish conclusively whether the ground water is
compatible for the evaporator of a heat pump (see table).
If one characteristic is negative "-" or two characteristics are "0",
the water quality is not sufficient for the heat pump.
If the necessary water quality is not achieved or if this cannot be
guaranteed long-term, we recommended installing a brine-to-
water heat pump equipped with an intermediate circuit.
Table:
Resistance of copper-soldered stainless steel plate heat ex-
changers to substances contained in the water
+ Normally good resistance
0 Corrosion problems can arise,
particularly if several factors receive an evaluation of "0"
- Should not be used
[<: less than, >: greater than]
Evaluation characteris-
Substances that can settle (org.)
Ammonia NH
Chloride
Electrical conductivity
Iron (Fe), dissolved
Free (aggr.) carbonic acid
Manganese (Mn), dissolved
Nitrate (NO
3
PH value
Oxygen
Hydrogen sulphide (H
2
HCO -/SO
3 4
Hydrogen carbonate (HCO
Aluminium (Al), dissolved
Sulphate
Sulphite (SO
Chlorine gas (Cl
452237.66.11 · FD 9908
Approximate
concentration
tic
range (mg/l)
< 2
3
2 to 20
> 20
< 300
> 300
< 10  S/cm
10 to 500  S/cm
> 500  S/cm
< 0.2
> 0.2
< 5
5 to 20
> 20
< 0.1
> 0.1
< 100
), dissolved
> 100
< 7.5
7.5 to 9
> 9
< 2
> 2
S) < 0.05
2
> 0.05
> 1
-
< 1
-) < 70
3
70 to 300
> 300
< 0.2
> 0.2
< 70
70 to 300
> 300
), free
< 1
3
) < 1
2
1 to 5
> 5
WI 65TU - WI 95TU
Evaluation of
the copper
0
+
0
-
+
0
0
+
-
+
0
+
0
-
+
0
+
0
0
+
0
+
0
+
-
+
0
0
+
0
+
0
+
0
-
+
+
0
-
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