Installation Guide

Rinnai Tankless Water Heater Installation and Operation Manual 81
Parameter Settings
Refer to section “4.13 Configure Parameter Settings” for instructions on how to access and change
parameter settings.
Table 34: Maximum Pipe Length*
(Maximum pipe length includes the hot water supply line and dedicated return line.)
Pipe Diameter 3/4 in. 1/2 in.
Total 400 ft. (122 m) 100 ft. (30 m)
05
Recirculation Modes
•
Economy (Factory Default): Adjust parameter setting to 05A for Economy mode. This mode
cycles the pump less often, using less energy to maintain the circulation loop temperature.
•
Comfort: Adjust parameter setting to 05b for Comfort mode. This mode cycles the pump more
frequently, ensuring the loop temperature remains higher (but also uses more energy).
•
Commercial: Adjust parameter setting to 05C for Commercial mode. This mode cycles the pump
on and off continuously, which may result in excessive machine wear and energy consumption.
Setting #
Setting
Description
Selection
A b C d
04
Recirculation Settings
No
Recirculation
Recirculation
(Dedicated)
Recirculation
(Crossover)
05
Recirculation Mode Economy Comfort Commercial
04
Recirculation Settings
Crossover Mode: Adjust parameter setting to 04c for crossover recirculation applications. Maximum
recirculation loop length of 400 ft (122m) with 3/4 in. pipe or 100 ft (30m) with 1/2 in. pipe
*Take equivalent elbow lengths and all fittings into consideration when calculating pipe length.
Note: If your recirculation loop length exceeds the length listed in the above table, the recirculation
loop may not provide proper heat to all fixtures.
Pump Status Typical Intervals
Economy 10
Off
Comfort 4
Commercial 4
The internal pump in a CXP model runs
based on time intervals only and not
water temperature (like dedicated return
line recirculation systems).
IMPORTANT
Table 33
Table 35