Specifications
41
5. Bond all above-ground gas piping to a 
grounding electrode and ensure the piping is 
electrically continuous.
 DO NOT USE GAS PIPING AS A 
 GROUNDING ELECTRODE. Refer to 
National Electrical Code, NFPA 70.
6.  Install sediment trap, ground-joint union and 
manual shut-off valve upstream of boiler gas 
control valve and outside jacket.
7.  When the piping is completed, test it for 
leaks.
(1)  When testing over ½ psig, disconnect 
 the boiler and its individual shut-off valve  
 from the gas supply piping.
APPENDIX C – Gas Piping (continued)
(2)  When testing at ½ psig or less, isolate 
 boiler from gas supply piping by closing 
 boiler’s individual manual shut-off valve.
(3) Locate leaks using approved 
 combustible gas detector or 
 nonammable, non-corrosive leak 
 detection solution.
 DO NOT CHECK FOR LEAKS USING 
 OPEN FLAMES such as matches or 
candles or devices that spark.
8.  Repair any detected leaks.
APPENDIX D – SYSTEM PIPING
 USE PROPER DESIGN AND INSTALLATION PRACTICES and observe all local codes when 
 installing system piping. Property damage and injury may result from an improperly piped or 
designed heating system.
i 
 Boiler damage caused by flawed system design or operation is excluded from our warranty.
Training and experience is required to design and install a piping system that will protect the boiler and 
provide many years of comfort to the building occupants. Be sure to protect the boiler from the following 
problems:
1.  Corrosion
(1) Comply with the boiler’s specic 
water quality requirements. See the 
Specifications Section of this manual.
(2)  Pressurize the system above the highest 
 net positive suction head (NPSH) 
 required for each circulator and ensure 
 positive pressure at the uppermost point 
 in the system.
(3)  Maintain a closed boiler system using 
 heat exchangers to transfer heat to 
 open systems, such as domestic hot 
 water systems.
(4)  Purge the system completely of 
 dissolved oxygen by bleeding all 
 radiators and installing a properly 
 installed air scoop or air vent.
(5)  Repair leaking pipes, ttings, and vents 
to minimize the need to add makeup 
water.
(6)  Do not ll the boiler with softened water 
unless makeup water is extremely hard 
and it is not possible to eliminate all 
system leaks. If lling the boiler with 
softened water, test regularly the water 
softener regularly to ensure that brine 
solution is not entering the boiler’s water 
supply.
2.  Lime scale
(1)  Repair leaking pipes, ttings, and vents 
 to minimize the need to add makeup 
 water.
(2)  Comply with the boiler’s specic     
 water quality requirements. See the 
 Specifications Section of this manual.
(3)  Comply with the boiler’s specic     
 requirements for minimum water ow 
 through the boiler, installing a system 
 bypass or primary-secondary loop if 
 necessary to maintain ow through the 
 boiler when serving small zones.










