User manual

Installation & Servicing Instructions Rinnai Q-Series
19
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
fl ow over the boiler. If not the boiler will switch off.
The electrical side of the external circulation pump (fi g. 6, 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 fl ow.
As standard the boiler is provided with a water fi lter 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.
NOTICE
i
pump index lines UPER 20-58 graph 1a
pump index lines UPER 20-78 graph 1b
UPER 20-78
25%
UPER 20-78
100%
Resistance
Q175S
Resistance
Q175C
Resistance
Q205C
Resistance
Q130S
Resistance
Q85S
UPER 20-58
25%
UPER 20-58
100%