Rinnai Q85SN Installation & Servicing Instructions Manual page 23

Water fi lter fi gure 9a
i
NOTICE
pump index lines UPER 20-58
pump index lines UPER 20-78
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. 7, pos. 2) 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 to 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 (fi g.
9a), so that debris from the central heating water is prevented from affecting the boiler.
The boiler is designed to be used on pressurized heating systems only (closed
loop).
Q85S
14
12
10
8
6
4
2
0
0 2
UPER 20-58
14
Q130S
Q175S
Q175C
12
Q205S
10
8
6
4
2
0
0 2
UPER 20-78
25%
4 6
Q [gallons/min]
25% UPER 20-58
4 6
Q [gallons/min]
UPER 20-78 Restistance
100% Q175S
8 10
100% Resistance Q85S
8 10
Resistance Resistance
Q175C Q205S
32.3
27.7
23.0
18.5
13.8
9.2
4.6
0
12
graph 1a
32.3
27.7
23.0
18.5
13.8
9.2
4.6
0
12
Resistance
Q130S
graph 1b
23