Rinnai FUA-E, Service Manual

Page: 16 / 67

16
The water pressure vs. flow characteristics are as follows:
Regardless of how high the incoming water pressure is it is not possible to obtain more than
20 L/min from the Rinnai Infinity 16i. In order to have this much flow the temperature rise
must be low enough that the unit has the capacity to satisfy the temperature setpoint for this
flow rate. For higher temperature rises the flow rate will be lower, regardless of the incoming
pressure.
The water heater has a water flow regulator that will throttle the flow rate back to make sure
that the unit only supplies water at the required temperature. If demand exceeds the
capacity of the unit, the unit will limit the water flow so the temperature does not alter.
The water heater’s heat exchanger has a much higher pressure drop at high flow rates then
at low flow rates. For low pressure installations use higher temperature set points.
In order to achieve maximum flow rate 1.5 bar pressure is required. The unit will operate on
lower pressures. It is advisable to have at least 1.1 bar pressure.
0
5
10
15
20
25
0 1 2 3 4 5 6 7 8
WATER PRESSURE
（
bar
）
WA
TE
R
VO
L
U
M
E
（
L/
m
in
）
Water Pressure vs. Flow