Service manual
SC Series Boilers – Installation and Service Manual
13
Super Hot SC series boilers are designed for use in closed loop systems and are not intended for open
systems, as in heating pool water or systems where water is constantly replenished. Operating the boiler
in an open system will result in premature failure of the heat exchanger. Super Hot boilers may be used
to heat water in open systems indirectly by installing a heat exchanger, such as the Super Hot C-Coil, to
separate open and closed systems.
Heating systems with low temperature return water may cause flue gas moisture to condense on the
boiler heat transfer surfaces, causing corrosion and restricting flue gas flow. Also, low temperature return
water may overcool the flue gases, resulting in reduced vent suction. These are natural phenomena and
are independent of the boiler design. As a guide to avoiding such corrosion and draft problems, it is
imperative that the return water be not less than 135°F (57°C).
THE BOILERS MUST ALWAYS BE USED WITH FORCED SYSTEM CIRCULATION.
2.10 PRESSURE RELIEF VALVE
A pressure relief valve is supplied as standard equipment. The
pressure relief valve is extra protection against damage that could
be caused by malfunctioning controls or excessive water pressure.
If a pressure relief valve is not used, the warranty is void.
The pressure relief valve should be installed on the boiler outlet
with its spindle vertical. The connection between the boiler and the
relief valve must have at least the area of the valve inlet.
A discharge pipe should be used. The discharge pipe outlet should
be positioned over a suitable drain and so arranged that there will
be no danger of being scalded. The discharge pipe must pitch
down from the valve and should be no smaller than the outlet of the
valve. The end of the discharge pipe should not be concealed or
threaded and should be protected from freezing. Extensive runs,
traps or bends could reduce the capacity of the pressure relief
valve.
No valve of any type should be installed between the pressure relief valve and unit or in the discharge
pipe. The pressure relief valve is a code requirement. Field installation of the relief valve must be
consistent with the ANSI/ASME Boiler and Pressure Vessel Code, Section IV.
Avoid contact with the hot water discharged to prevent personal injury.
2.11 ELECTRICAL WIRING
All electrical wiring must conform to the requirements in Section 2.2.
Run a separate circuit from the electrical service panel through a fused disconnect switch to the boiler.
This boiler must be electrically bonded to ground in accordance with the requirements of the authority
having jurisdiction or, in the absence of such requirements, with the National Electrical Code, ANSI/NFPA
70 (current edition) and and/or the Canadian Electrical Code, CSA C22.1 Part 1 (current edition). Field
wiring shall conform to Section 2.2 and to the temperature limitations of Type T [63°F (35°C) rise] or
better.
Make connections as shown in the wiring diagrams provided. For details of electrical wiring for different
ignition controls, refer to wiring diagrams included in this manual on page 29 to 31.