Rinnai HDC 1600i Low NOX Installation And User Manual page 17

Sequence of Operation
DIP switches (SW2 - #3, #4) should be set correctly for recirculation and mode.
The Rinnai water heater should be turned on.
Pump recirculation begins when the water heater is turned on.
The Rinnai inlet and outlet thermistors measure the water temperature.
The water heater produces hot water at the temperature setting.
If the inlet thermistor detects abnormal temperature then diagnostic code 51 is generated and the
pump will turn off.
When the return water temperature reaches approximately 8°C below the temperature setting, the
water heater and pump will turn off.
The cycle will restart at the approximate time interval in the table based on the temperature thermistor
readings.
Economy Mode
The Economy mode operates as follows:

Less energy consumed due to fewer pump cycles

Assumes plumbing is insulated (minimal pipe heat
loss)

Pump cycles on every 31 to 79 minutes (see
table).
Comfort Mode
The Comfort mode operates as follows:

Higher energy consumption due to more pump
cycles

Assumes plumbing is not insulated resulting in
higher pipe heat loss

Pump cycles on every 15 to 39 minutes (see
table).
* The pump will cycle on at these calculated intervals
which are based on the temperature setting,
insulation, and estimated heat loss in the system.
The values for your installation may vary.
NOTE: the function Recirculation Mode is available only using the remote
MC-91-3A.
Remote MC-91Q-3A is dedicated to recirculation unit REU-CUG1.
RECIRCULATION MODE
Typical Pump ON Intervals
Rinnai
Temperature
Setting
Economy
°C
Mode
65
60
55
50
48
46
45
44
43
42
41
40
39
38
37
17
*
(minutes)
Comfort Mode
31 15
31 15
31 15
31 15
35 18
35 18
35 18
42 21
42 21
45 22
49 24
54 27
60 30
68 34
79 39