Connection On Heating Side; Frost Protection - Dimplex LA 18I-MU Montage- Und Gebrauchsanweisung

LA 18I-MU

7.2 Connection on heating side

The heating system connections on the heat pump are to be
made inside the device. Refer to the device information for the
connection sizes. The connection hoses are routed out of the de-
vice in a downwards direction. A Wellflex hose set is available as
an accessory for this. Side openings in the frame also enable
lines to be routed at the side. A spanner must be used to firmly
grip the transitions when connecting the heat pump.
Before connecting the heating water system to the heat pump,
the heating system must be flushed to remove any impurities,
residue from sealants, etc. Any accumulation of deposits in the
liquefier may cause the heat pump to completely break down.
Once the heat pump has been connected to the heating system,
it must be filled, purged and pressure-tested.
The following points must be observed when filling the system:
 Untreated filling water and make-up water must be of drink-
ing water quality
(colourless, clear, free of sediments)
 Filling water and make-up water must be pre-filtered (max.
pore size 5 µm).
Scale formation in domestic hot water heating systems cannot be
avoided, but in systems with flow temperatures below 60 °C, the
problem can be disregarded. With high-temperature heat pumps
and in particular with bivalent systems in the higher performance
range (heat pump + boiler combination), flow temperatures of
60 °C and more can be achieved. The following standard values
should therefore be adhered to with regard to the filling and
make-up water according to VDI 2035, sheet 1: The total hard-
ness values can be found in the table.
Total alkaline
Total heat
earths in mol/m³
output in kW
and/or mmol/l
≤ 2,0
< 50
50 - 200 ≤ 2,0
200 - 600 ≤ 1,5
> 600 < 0,02
1. This value lies outside the permissible value for heat exchangers in heat
pumps.
Fig. 7.1:Guideline values for filling and make-up water in accordance with
VDI 2035
For systems with an above-average specific system volume of
50 l/kW, VDI 2035 recommends using fully demineralized water
and a pH stabiliser to minimize the risk of corrosion in the heat
pump and the heating system.
NOTE
With fully demineralized water, it is important to ensure that the minimum
permissible pH value of 7.5 (minimum permissible value for copper) is
complied with. Failure to comply with this value can result in the heat
pump being destroyed.
ATTENTION!
The notes/settings in the instructions of the heat pump manager must
always be observed and carried out accordingly; not doing so will lead to
malfunctions.
www.dimplex.de
Specific system volume
(VDI 2035) in l/kW
< 20 ≥ 20 < 50 ≥ 50
Total hardness in °dH
≤ 16,8 ≤ 11,2
≤ 11,2 ≤ 8,4
< 0,11
≤ 8,4
1
< 0,11
1
< 0,11
452168.66.09 · FD 9706
Minimum heating water flow rate
The minimum heating water flow rate through the heat pump
must be assured in all operating states of the heating system.
This can be accomplished, for example, by installing either a dual
differential pressureless manifoldeiner or an overflow valve. The
procedure for setting an overflow valve is described in the chap-
ter "Commissioning". If the minimum heating water flow rate is
not reached, the heat pump is blocked.
The nominal flow rate is specified depending on the max. flow
temperature in the device information and must be taken into ac-
count during planning. For return temperatures under 30 °C, the
flow must be designed for the nominal conditions.
The specified nominal flow rate (See "Device information" on
page 14) must be guaranteed in every operating status. An in-
stalled flow rate monitoring sensor is used only for switching off
the heat pump in the event of an unusual and abrupt drop below
the minimum heating water flow rate and not for monitoring and
safeguarding the nominal flow rate.
NOTE
The use of an overflow valve is only recommended for panel heating and
a maximum heating water flow of 1.3 m³/h. System faults may result if this
is not observed.

Frost protection

On heat pump systems where protection from frost cannot be
guaranteed, there must be an option for draining the system (see
figure). The frost protection function of the heat pump manager is
active whenever the heat pump manager and the heat circulating
pump are ready for operation. If the heat pump is taken out of
service or in the event of a power failure, the system has to be
drained. If heat pump systems are implemented in buildings
where a power failure cannot be detected (holiday homes etc.),
the heating circuit should be operated with suitable frost protec-
tion.
1
English
EN-7