Navien NHB Series Installation & Operation Manual page 105

Setting the Operation Strategy
To set the operation strategy (operating algorithm), select the strategy from Comfort (default), Eco, or Boost. The detailed information for
each mode is as follows.
Late On/Early Off
Operating method
Feature
Condensing
effectiveness
Heat responsiveness
depending on a small
amount of load changes
Heat responsiveness
depending on a large
amount of load changes
Comfort
This mode minimizes the amount of times the unit cycles ON and OFF. However, it requires additional unit operation time (Low Off HC). Refer
to the following operating diagram for the detailed information.
95%
60%
Comfort
Early On/Late Off
Unit On HC: 95%
(Late Unit On)
Unit Off HC: 30%
(Late Unit Off)
Minimizes switches from Maximizes the unit
On/Off in the unit. operation.
47.5% 47.5%
Unit ON
Unit OFF 30% 30%
Eco
Late On/Early Off
Unit On HC: 60% Unit On HC: 95%
(Early Unit On) (Late Unit On)
Unit Off HC: 30% Unit Off HC: 50%
(Late Unit Off) (Early Unit Off)
Minimizes the unit
operation.
95% 95%
Unit ON
63.3% 63.3% 63.3%
30% 30% 30%
Unit OFF
45% 45%
Boost Custom
Unit On HC: The value of
Unit On HC
(Default: 70%)
Unit Off HC:The value of
Unit Off HC
(Default: 30%)
On/Off in the unit is
determined by custom
settings.
100% 100% 100%
Operating the Boiler 105