Hydronic piping, Near boiler piping connections, Circulator sizing – Lochinvar Kight XL 400-801 User Manual
Page 17: Variable speed pump option

17
3
Hydronic piping
(continued)
Near boiler piping connections
Y-STRAINER
(RECOMMENDED)
BOILER PUMP
 INDIRECT
 DOMESTIC
HOT WATER
 TANK
TO FLOOR
 DRAIN
TO
FR
OM
FR
OM
SY
ST
EM
TO
SY
ST
EM
DOMESTIC HOT
WATER PUMP
AIR SEPARATOR
SYSTEM SENSOR
IMG00413
SYSTEM PUMP
Figure 3-4A Near Boiler Piping w/Y-Strainer
Circulator sizing
The Outdoor Knight XL heat exchanger does have a pressure 
drop, which must be considered in your system design. Refer 
to the graphs in FIG’s 3-5 and 3-6 for pressure drop through 
the Outdoor Knight XL heat exchanger.
 DRAIN
(TYPICAL)
AIR SEPARATOR
AIR VENT VALVE
EXPANSION TANK
LOW LOSS HEADER
 (TYPICAL)
Y-STRAINER
(RECOMMENDED)
DRAIN
VALVE
FAST FILL VALVE
 INDIRECT
 DOMESTIC
HOT WATER
 TANK
SYSTEM SENSOR
SYSTEM PUMP
TO FLOOR
 DRAIN
TO
FR
OM
FR
OM
SY
ST
EM
TO
SY
ST
EM
BOILER PUMP
IMG00391
Figure 3-4B Near Boiler Piping w/Low Loss Header
12. Boiler purge valve:
 
Field supplied. The boiler purge valve is used to
remove entrapped air from the heat exchanger during
start-up.
13. System temperature sensor:
 
Lochinvar supplies a system temperature sensor. The
sensor is to be installed in the heating loop downstream
from the boiler hot water piping and heating loop
junction. The sensor should be located far enough
downstream to sense system diluted water temperature.
14. Y-Strainer:
 
Field supplied. A Y-strainer or equivalent multipurpose
strainer is recommended at the inlet of the heat exchanger
to remove system particles from older hydronic systems
and protect newer systems.
Variable speed pump option
Variable speed pump setup
Before operation, ensure the following:
-
Pump is set for an input signal of 0 - 10VDC
by the dip switches on the pump control
- Pump is set for external signal control
(if
applicable)
-
Pump is set for linear output (if applicable)
- If pump does not come equipped with a
0 - 10 VDC input option, an optional module
will be required from the vendor
SMART SYSTEM / Multi-temperature
loop control option
The Outdoor Knight XL boiler is capable of producing 
up to three (3) set point temperatures to meet different 
space heating demands. When using more than one 
temperature demand it is necessary to protect the 
lower temperature loop from overheating. To help 
aid with this protection, Lochinvar offers the Multi- 
Temperature Loop Control Board Kit (RLY30086).
Outdoor Knight XL Installation & Operation
Manual
