Rinnai E50C Installation & Servicing Instructions Manual page 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 and controlled.
If the installation resistance is over the stated value; 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.
As standard the boiler is provided with a water fi lter in the return pipe of the boiler,
so that debris from the central heating water is prevented from affecting the boiler.
Water fi lter fi gure 8
i
The boiler is designed to be used on pressurized heating systems only (closed
NOTICE
loop).
The maximum available head pressure from the boiler pump for the system is
2 psi = 4.6 feet of head.
If the boiler is to be installed in a system that utilizes zone pumps and not zone valves
a low loss header plumbing kit should also be installed (part number: 804000061).
If the pressure drop in the loop/system is greater than the available head pressure
from the boiler pump a low loss header plumbing kit should be used (part number:
804000061).
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