4
x
Operation
20
BA ROTEX A1 B0 - 10/2007
Pump setting for energy-saving operation (A1 BO 20i)
The ROTEX oil condensing boiler A1 BO 20i is equipped with a three stage circulation pump which normally has enough output
to supply the complete heating system. Additional pumps are only required if mixed heating circuits are installed.
The other variants of the A1 BO oil condensing boiler have a controlled heating pump which the heating expert sets up optimally
during start-up. Manual adjustment of the pump output level is also possible on this pump, but is not required.
The pump fitted in the oil condensing boiler ROTEX A1 BO20i consumes approx. 75–80 W at output level 3, approx. 55–60 W
at output level 2.
Determination of the required pump level
• Determine the flow rate associated with a specific heating output in the heating output diagram (fig. 4-5) depending upon
the design spread.
Depending upon the heat demand and the temperatures the heating system is designed for, the circulation pump
can also be operated at a
reduced speed
without having a detrimental effect on the heat provided. This allows
you to save on electricity to drive the pump.
The operator can only use output levels 2 and 3 for pump adjustment. The lowest output level is blocked for
safety reasons.
Q
Heating output
m
H
Flow heating network
Fig. 4-5
Heating output diagram
The design spread describes the temperature difference between the flow and return flow of the heating system
under design conditions (generally –12 °C outside air temperature).
Δ
p
R
Remaining pumping height
m
H
Flow heating network
Fig. 4-6
Remaining pump height of the circulation pump fitted in the A1 BO 20i oil condensing boiler
S= 20 K
S= 15 K
S= 10 K
0
5
10
15
20
25
30
35
0
500
1000
1500
2000
2500
3000
13
700
m / L/h
H
Q/k
W
0
100
200
300
400
500
600
0
200 400 600 800 1000 1200 1400 1600 1800 2000
II
III
240
700
m / L/h
H
p
/
mbar
D
R
