Navien NHB-055 Installation & Operation Manual page 80

Setting the Boost Interval Time
Display
S R O/R psi
The boost interval time may be set to prevent interruption in
space heating while using the Outdoor Reset Control mode,
due to changes in heat load conditions. With the boost interval
time enabled, the boiler increases the space heating supply
temperature by 9°F (5°C) and the return temperature by 5°F (3°C)
after a set time elapses.
Boost Interval Time and Temperature Setting
Setting Range
Boost Interval
OFF (0), 1–120 min
Time
Space Heating Supply (Fixed
Value): 9°F (5°C)
Boost
Temperature
Space Heating Return (Fixed
Value): 5°F (3°C)
Setting the Max Heat Capacity for Space Heating
Display
S
R O/R psi
This menu is used to configure the desired space heating capacity.
When the boiler operates in Normal mode, the space heating
capacity is limited to the set value (%).
Default: 100%
Range: [Space heating Min heat capacity +20]% – 100%
80 Operating the Boiler
Description
Boost interval time (min)
Remarks
Default:
OFF (0)
Description
Space heating max heat capacity (%)
Setting the Pump Freeze Protection Temperature
Display
Pump freeze protection temperature
(°F)
S R O/R psi
This menu is used to configure the circulation pump freeze
protection temperature.
When the space heating supply temperature stays below the set
value for longer than 10 seconds, the boiler runs the circulation
pump to prevent freeze damage (the pump runs for 10 minutes,
then stops for 1 minute).
Default: 50°F (10°C)
Range: 43–50°F (6–10°C)
Setting the Anti-fast Cycling Time
Display
Anti-fast cycling time (min)
S R O/R psi
The anti-fast cycling time is the duration that the boiler stops
its space heating operation when the space heating supply or
return temperatures reach the set values for boiler operation stop
temperatures. The boiler will not resume space heating until the
duration elapses, even when the space heating supply or return
temperatures return to within the set ranges.
Default: 3 minutes
Range: 0–20 minutes
Description
Description