14
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
5.3 Safety Relief Valve
• 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).
5.4 Low Water Cutoff
These guidelines are supplied when necessary to install an
additional Low Water Cut Off (LWCO), for sensing a low water
level condition in a boiler, as required by the Authority Having
Jurisdiction.
• 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.
!
Required Close
Coupled Loop
Per Figure 5-4
System
Return
System
Supply
WALL
MOUNTED
ONLY
MINIMUM
ACCEPTABLE
HEIGHT FOR
LWCO PROBE
Low Water
Cutoff
(LWCO)
Installation if
required by
the Authority
Having
Jurisdiction
Check Local Codes
For Maximum
Distance To Floor
PN 240012369, REV A [08/31/2018]
5 - HYDRONIC PIPING
Check Local
Codes For
Maximum
Distance To
Floor
Safety Relief
Valve
Do not use
plastic pipe see
Warning
below
TP Gauge
FIGURE 5-3 System Piping - LWCO Probe Location
