F
d
b
b l
&
h
B l M
l
Finned copper tube gas boilers & water heaters – Boiler Manual
14
F
F
GENERAL PIPING REQUIREMENTS
Improper piping of this boiler/water heater will void
the manufacturer’s warranty and can cause boiler
failure resulting in flooding and extensive property
damage! Excessive water hardness causing scaling in
the copper heat exchanger tubes is NOT covered under
the manufacturer’s warranty. See Table 8, page 20.
Excessive pitt ing and erosion of the internal surface
of the copper heat exchanger tubes is NOT covered
under the manufacturer’s warranty if the result of high
water fl ow rates. See Table 7, page 16. Return water
temperatures below 140
o
F, 60
o
C will result in heat
exchanger damage from excessive condensation
voiding the manufacturer’s warranty, see Primary/
Secondary Piping. See Figure 9, page 15.
Shut off valves and unions should be installed at the
inlet and outlet connections of the boiler/hot water
heater to provide for isolation of the unit should
servicing be necessary.
Freeze protection
Installations in areas where the danger of freezing exists are not
recommended unless proper freeze protection is provided. The
following precautions MUST be observed:
1. A continuous flow of water through the unit MUST be
maintained! The pump responsible for flow through the
boiler/water heater must run continuously!
2. An ethylene glycol/water mixture suitable for the
minimum temperature that the unit will be exposed to
must be used. The pump must be capable of producing
a minimum of 15% more flow and overcoming a
20% increase in head loss. Domestic water systems must be
isolated from the water heater by the use of a heat exchanger or
other approved method.
3. If the unit must be shut off for any reason the electric,
gas and water supplies MUST be shut off and the unit
and its pump completely drained.
Improper outdoor installation of this unit can cause
boiler failure voiding the manufacturer’s warranty!
Relief valve
Pipe the discharge of the pressure relief valve as shown in Figure 9,
page 15.
Never install any type of valve between the boiler/
water heater and the relief valve or an explosion causing
extensive property damage, severe personal injury or
death may occur!
Flow Switch
Th e fl ow switch supplied with the boiler/water heater must be wired
to the terminal strip in the control panel to prevent the boiler from
fi ring unless there’s adequate water fl ow through the unit. Th e fl ow
switch must be installed in the supply piping adjacent to the boiler
outlet connection.
Failure to properly install the fl ow switch may result
in damage to the boiler/water heater heat exchanger
voiding the warranty!
HEATING SYSTEM PIPING
General piping requirements
All heating system piping must be installed by a qualifi ed technician
in accordance with the latest revision of the ANSI/ASME Boiler and
Pressure Vessel Code, Section IV, and ANSI/ASME CSD-1, Standard
for Controls and Safety Devices for Automatically Fired Boilers. All
applicable local codes and ordinances must also be followed. A
minimum clearance of 1 inch, 25 mm must be maintained between
heating system pipes and all combustible construction. All
heating system piping must be supported by suitable hangers not the
boiler. Th e thermal expansion of the system must be considered when
supporting the system. A minimum system pressure of 12 psig,
82.7 kPa must be maintained.
Heating boiler piping connections
Th e supply and return connections should be sized to suit the system,
per Table 6.
Table 6
Supply & Return Pipe Sizing
Input
MBH
Supply
size
Return
size
2500/3000
4" FLANGE
4" FLANGE
3500/4000
4" FLANGE
4" FLANGE
Pump requirements
This low mass boiler requires a continuous minimum
water fl ow for proper operation
. Th e boiler pump must be
sized to overcome the head loss of the boiler and the near-boiler
piping in order to achieve the required temperature rise. Table 7
provides the heat exchanger pressure drop and temperature rise
fi gures. Th e temperature rise across the boiler must never exceed
35
o
F, 19.4
o
C. Th e adjustable pump delay turns the pump on each
time the burner fi res and runs the pump for 20 to 600 seconds aft er
the call for heat is satisfi ed.
