Rinnai Q130SN Installation & Servicing Instructions Manual page 22

i
NOTICE
22
The boiler has a self-adjusting and self-protecting control system for the load and the pump
capacity. By this means the temperature difference between the supply and return water is
checked.
If the installation resistance is over the stated value; the pump will rotate at maximum capacity
and the load will be adjusted until an acceptable temperature difference between supply and
return water has been obtained. If, after this, the temperature difference is still not acceptable
then the boiler will switch off and wait until an acceptable temperature has arisen.
If an unacceptable temperature is detected, the control will repeatedly try to achieve water
flow over the boiler. If not the boiler will switch off.
The electrical side of the external circulation pump (fig. 7, pos. 9) can be connected to the
Control Tower. This pump thus switches simultaneously to the boiler pump.
The maximum absorbed current consumption of the external circulation pump may not
exceed 120V, 2 Amp. If a pump with a larger current draw is required an isolation relay
must be used. See the Rinnai Boiler applications manual for further information. The extra
external pump must be selected according the installation resistance and required flow.
As standard the boiler is provided with a water filter in the return pipe of the boiler, so that
debris of the central heating water is prevented from affecting the boiler.
The boiler is designed to be used on pressurized heating systems only.
14
12
10
8
6
4
2
0
0 2
UPER 20-58 25%
pump index lines UPER 20-58
14
12
10
8
6
4
2
0
0 2
UPER 20-78 UPER 20-78
25% 100%
pump index lines UPER 20-78
4 6
Q [gallons/min]
UPER 20-58 100%
4 6
Q [gallons/min]
Restistance Resistance
Q175S Q175C
8 10
Resistance Q85S
graph 1a
8 10
Resistance Resistance
Q205S Q130S
graph 1b
32.3
27.7
23.0
18.5
13.8
9.2
4.6
0
12
32.3
27.7
23.0
18.5
13.8
9.2
4.6
0
12