(7) An expansion tank must be installed (see Fig. 3) to allow for water expansion as the
system is heated.
Dissimilar Metals
Do not connect dissimilar metals on the inlet and outlet nipples. Dielectric Unions should be
used. Another solution is to use brass or cast iron fittings between the boiler and any copper
fittings that you may be using. Failure to do so will result in galvanic corrosion and cause the
inlet and/or outlet nipples to fail over time.
This is not covered under the warranty.
Pump Installation
The circulation pump should be positioned as close to the boiler as possible, with the delivery
arranged to pump out of the tank outlet on the upper left side of the boiler (see Fig. 3)
The pump is powered by the boiler through terminals PL and PN located on the 120 volt
terminal block (lower right terminal block see Fig. 4 and Fig. 5). The pump starts when the
thermostat terminals on the control board are closed, and stops when these terminals are
opened.
If desired, the pump may be operated continuously during the heating season. Should you
decide to wire the pump in this manner, it should be wired to the same supply circuit as the
boiler to prevent the pump from being turned off while the boiler is still powered.
Thermostat Connection
The thermostat connection is 24 volt AC.
Only connect the thermostat after all
other work is complete, and the entire heating system is thoroughly
purged of air.
The thermostat is connected to the terminals “STAT 1” on the control circuit
board (see Fig. 4 and Fig. 5). In zoned systems, the end switches of all the zone valves may be
connected in parallel and hooked up to the thermostat connection on the control board. For a
typical system (see Fig. 6).
Thermostats described as “Power Stealing” or as “Parasitic Thermostats”
must not be used.
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