Circulation Pump; Water Flow; Water Pressure - DeDietrich C230 ECO-A 120 Installation, Operating And Service Manual

5 Water-side connections
Fig. 4 Output control characteristic
V = full load P = heat output
D = part load ∆T = temperature
difference
20

Please ensure that the new boiler plant is not in circuit when the
flushing takes place, especially if cleansing chemicals are used to
assist the process.
It is important to check the inhibitor concentration after installation,
system modifications, filling the system and every service in
accordance with these instructions.
For the correct dosage and the suitability of inhibitors for use with our
boilers and for further information on water treatment or system
cleaning we advise you to contact a water treatment company who is
experienced with our boilers.
5.1.3

Circulation pump

The boiler is equipped with a pump switch to connect an
external circulation pump. This pump is run once every 24
hours to prevent sticking (24 hour pump operation).
Only on/off pumps can be controlled. For connections, see
Section 8.4.6.
The hydraulic resistance for the various output options of the
boiler is as follows:
Boiler Hydraulic resistance
model
at a dT of 36°F (20°C)
mbar
C230 80 165
C230 120 135
C230 160 170
C230 200 180
5.1.4

Water flow

The maximum temperature difference between flow and return, and
the maximum rate of rise of the flow temperature and boiler block
temperature are limited by the boiler's modulating controls. As a
result, the boiler is virtually unaffected by low water flow. However for
a continuous supply of heat, the boiler requires a minimum flow of
30% of the nominal flow at the relevant design temperatures.
5.1.5

Water pressure

The boiler is suitable for a maximum working pressure of 100 psi (6.8
bar) according to ASME MWAP = 100 psi. The minimum operating
pressure shall not be less than < 11.6 psi (0.8 bar).
Hydraulic resistance
at a dT of 18°F (10°C)
psi mbar
2.39 545
1.96 446
2,47 562
2,61 595
C230 ECO-A
psi
7.90
6.47
8.15
8.63