System
Return
System
Supply
WALL
MOUNTED
ONLY
MINIMUM
ACCEPTABLE
HEIGHT FOR
LWCO PROBE
Check Local Codes
For Maximum
Distance To Floor
12
WARNING
Burn and scald hazard. Safety relief valve could
discharge steam or hot water during operation.
Install discharge piping per these instructions.
!
FIGURE 5-2 Safety Relief Valve Discharge Piping
5 - HYDRONIC PIPING
5.3 Safety Relief Valve and Air Vent
•
Install safety relief valve using pipe fitting provided with
boiler. See figure 5-1
• Install safety relief valve with spindle in vertical position.
• Do not install shutoff valve between boiler and safety
relief valve.
• Install discharge piping from safety relief valve.
• Use ¾" or larger pipe.
• Use pipe suitable for temperatures of 375°F (191°C) or
greater.
• Individual boiler discharge piping shall be independent
of other discharge piping.
• Size and arrange discharge piping to avoid reducing
safety relief valve relieving capacity below minimum
relief valve capacity stated on rating plate.
• Run pipe as short and straight as possible to location
protecting user from scalding and properly drain piping.
• Install union, if used, close to safety relief valve outlet.
• Install elbow(s), if used, close to safety relief valve
outlet and downstream of union (if used).
• Terminate pipe with plain end (not threaded).
Check Local Codes For
Maximum Distance To
Floor
5.4 Low Water Cutoff
• Boiler is equipped with Low Water Pressure Switch.
•
Low Water Cutoff (LWCO) probe location. See figure 5-3
for minimum probe height. Do not install shutoff valve
between boiler and LWCO probe.
• If using separate stand pipe, install air vent using tee to
avoid nuisance shutdowns.
• Arrange piping to prevent water dripping onto boiler.
• Connect probe signal wires to shutdown terminal (BL) on
control board.
WARNING
Fire, explosion hazard. Mount boiler vertically or
slightly tilted backward to insure proper function of
low water cutoff. Failure to follow these instructions
could result in death or serious injury.
!
Safety Relief Valve
FIGURE 5-3 System Piping - LWCO Probe Location
P/N 240011654, Rev. C [06/08/2017]