Boiler Manual

Cast Iron Condensing Boilers – Installation Manual
GENERAL PIPING REQUIREMENTS
Improper piping of this boiler will void the
manufacturer’s warranty and can cause boiler
failure resulting in flooding and extensive
property damage!
Shut off valves and unions should be
installed at the inlet and outlet connections
of the boiler to provide for isolation of the
unit should servicing be necessary.
Relief Valve
Pipe the discharge of the pressure relief valve as shown
in Figure 9. Mount on rear section or vertically on supply
nipple.
Never install any type of valve between the
boiler and the relief valve or an explosion
causing extensive property damage, severe
personal injury or death may occur!
Flow Switch
The fl ow switch (optional on KN-6, 10, and 20; standard
on KN-16, 26 and 30) is wired to prevent the boiler from
fi ring unless there's adequate water fl ow through the
unit.
If using the optional flow switch, failure to
maintain the minimum flow rates listed in
Table 6 at the boiler outlet will prevent the
fl ow switch from closing. If a minimum fl ow
rate cannot be maintained at the boiler outlet
the fl ow switch will have to be relocated in the
system.
Table 6
Water
Flow Rates
(GPM)
Increase flow rates approximately 30% for glycol
mixtures.
Figure 9 - Relief Valve Piping
*ΔT Across
Heat Exchanger
Min. Max. Min. * Max.
KN-6 10 100 20°F 100°F
KN-10 15 150 20°F 100°F
KN-16 24 240 20°F 100°F
KN-20 30 300 20°F 100°F
KN-26 38 380 20°F 100°F
KN-30 45 450 20°F 100°F
*Min/Max Δt corresponds to full input, for applications
requiring operation above and/or below these parameters,
please consult manufacturer.
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