Installation instructions E-SHR series page 9
6.1 Central heating system
The boiler pipes can be connected to the installation by
means of compression fittings. Reducers should be used
for connecting to thick-walled pipe (welded or threaded).
The boiler has a self-adjusting and self-protecting control
system for the load capacity. By this means the temperature
difference between the flow and return water is checked. The
circulation pump will be able to supply the given water
displacement with an installation resistance of up to 18 kPa,
for this see table 3.
If the capacity of the boiler pump is insufficient, an extra
external pump can be installed in series with the boiler.
The electrical side of this external circulation pump can
be connected in the Control Tower, by which means this
pump switches at the same times as the boiler pump.
The maximum absorbed current consumption of the
external circulation pump may be 230 W (1 Amp).
If the installation resistance is higher than the stated value
the load will be adjusted until an acceptable temperature
difference between flow and return water has been
obtained. If, after this, the temperature difference remains
too much then the boiler will switch itself off and wait until
an acceptable temperature has arisen.
If an unacceptable temperature is detected, then the
control will repeatedly try to achieve water flow, and if this
does not work then the boiler will switch off.
available water flow at full load
table 3
external installation pump in series
figure 6
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pump index lines
graph 1
Q(m³/h)
Pumpcharacteristic UP 20-60
24T/35T
15/24
Pumpcharacteristic
UPS 20-50 (pos. 1)
H(m)
As standard the boiler is provided with a water filter in the
return pipe of the boiler. With this, possible contamination
of the central heating water is prevented from ending up
in the boiler. The boiler is also provided with an internal
safety valve set at 3 bar. This is connected by means of
a combination waste to the condensate discharge.
If all, or a large number of radiators are provided
with thermostatic radiator valves it is advisable to
use a pressure difference control (bypass) in order to
prevent flow problems in the installation.
The boiler is designed to be used on sealed
system only.
Additives in the installation water are only
permitted in consultation with the country
distributor.
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Pumpcharacteristic
UPS 20-50 (pos. 2)
