FTV I&O Manual
│
Boiler and Heating System Piping
39
Near Boiler Plumbing (Central Heating)
FTV boilers are intended solely for use in pressurized closed-loop heating systems operating with a minimum
pressure of 12 PSI at the boiler outlet. Carefully follow the instructions and piping diagrams illustrated in this
section.
FTV boilers are not approved for operation in an “open system,” thus it cannot be used
for direct potable water heating or process heating of any kind.
Pressure Relief Valve –
A Pressure Relief Valve is factory supplied with each unit, and must be field installed
in the vertical position, with the outlet facing horizontally and piped towards the floor away from where it
could be harmful; see Figure 10-2(a).
NOTICE:
FTV boilers have a maximum allowable operating pressure
of 50 PSI.
If installed in the incorrect orientation (horizontally with drain pipe out the bottom) the
relief valve may not function properly resulting in property damage or personal injury.
Ensure the discharge of the pressure relief is piped to a location where the steam or water
will not cause property damage or serious injury.
Pressure & Temperature Gauge –
FTV boilers come with a factory supplied Pressure and Temperature
Gauge. The gauge must be installed at the boiler outlet prior to any circulators. See Figures 10-2(b), 10-2(c),
and 10-2(d).
Auto Air Vent
– Install the factory supplied auto air vent directly above the outlet fitting on the top of the unit as
illustrated in Figure 10-2(a). Open the auto air vent’s vent-cap to promote the removal of air during
commissioning of the boiler and to avoid malfunctioning of the LWCO. Once the air is removed from the
system, close the vent-cap to prevent water from leaking onto the boiler.
Low Water Cutoff (LWCO)
– FTV boilers are provided with a factory installed Water Pressure Sensor. The
sensor provides a reading of the boiler inlet water pressure on the display; in the event the pressure drops
below 7 PSI, the control will go to a blocking error “FILL”, inhibiting burner operation. Where required by
the Authority having jurisdiction, an external LWCO may have to be installed; see Figure 10-1.
Figure 10-1 Installation of Optional LWCO
Auto Air Vent
– locate above the
LWCO to remove air during
commissioning (close vent-cap
afterwords to prevent water damage)
Low Water Cutoff Location
(when required by local authorities)
Install the LWCO in a suitable tee
(reference
installation instructions provided with the LWCO)
as illustrated.
DO NOT
install isolation valves
between the boiler and the LWCO. The LWCO
switch must be wired to break the boiler limit
circuit or line power to the boiler (see Section
12.0
– Field Wiring).
NTI offers the following LWCO kit p/n 85253.
When the installation is complete,
TEST THE
LWCO
to ensure the burner shuts down when the
water level drops.
