P-K SOLIS™
Gas Fired Boiler
Technical Service 1.877.728.5351
Revised: March 15, 2021
Released: March 15, 2021
Patterson-Kelley 2021
All Rights Reserved.
2701000090 P-K SOLIS NURO Installation and
Owners Manual (Rev A).docx
Page 44
Boiler Inlet and Outlet Connections
All water connections should be in compliance with national, state, and local code requirements. The bottom
rear connection to the boiler is the INLET and must be used for the return from the system. The top rear
connection to the boiler is the OUTLET and must be connected as the supply to the system. All water piping
must be installed such that no stresses are transmitted to the boiler. The boiler
shall not
be used as a pipe
anchor
.
Boiler Water Piping (for Installer)
Strainer
To avoid possible contamination of the boiler with dirt, rust, or sediment from the system, a strainer
near the boiler inlet is strongly recommended. Even new systems may contain sufficient foreign
material to eventually reduce the performance of the heat exchanger. Adequate circulation of good
clean water is essential for maximum efficiency and long life of the boiler. Refer to
Appendix D – Best
Practices For New & Retrofit Systems
for more information on best piping practices.
Heat
Exchanger
Relief Valve Piping
Each boiler is supplied with a pressure-relief valve sized in accordance with ASME requirements. The
relief valve discharge must be piped to an acceptable drain at a safe point of discharge. Reducing
couplings or other restrictions are not permitted in the discharge line.
The SL-1500, SL-2000, SL-2500, and SL-3000 boilers require an ASME Section IV relief valve to be
installed on the top of the OUTLET (Supply) connection. The spindle of the relief valve must be vertical.
The ASME Section IV relief valves are available for purchase from Patterson-Kelley.
Low Water Cut-Off
The boiler is furnished with a probe-type low water cut-off; no field piping is required. If the water level in
the boiler drops below the probe, the boiler will shut down and LOCKOUT LOW WATER LEVEL will be
displayed on the control panel. The low water cutoff circuit will automatically reset
when the low water
condition clears; however, the boiler controls will retain the lockout condition until the reset button on the
display is depressed. Installation of external limit controls may be required by certain codes or in certain
installations. Review applicable local codes for details
.
Drain Valve and Piping
The P-K SOLIS™ boilers feature a drain connection. Prior to draining the boiler, electrical power and
gas supply must be turned off to the boiler, and the boiler must be isolated from the system at the supply
and return connections
.
NOTICE!
Some local jurisdictions may require an auxiliary low water cut-off device installed in the
external piping. The auxiliary low water cutoff device only prevents operation when the water level
in the appliance is insufficient. It does not detect low water conditions in other parts of the system.
Installation of automatic air vents in the “high points” of the piping or additional low water safety
devices should be considered to protect the system.
NOTICE!
The manual drain is for draining the water inside the heat exchanger only, not the entire
hydronic or domestic system. Draining the entire system through the boiler or water heater’s drain
valve will deposit sediment and debris from the system inside the heat exchanger. This will result in
poor heat transfer and premature failure. Refer to
Appendix D – Best Practices For New &
Retrofit Systems
for more information on best piping practices.
N
OTICE
!
Heat exchangers have a minimum water pressure of 14.5 psi.
