Central Boiler CLASSIC Owner's Manual page 13

If not mounted on the furnace, the circulation pump(s)
need to be mounted 4 to 5 feet lower than the top water
level in the furnace (see Fig. 13 & 14). It is recommended
to mount the pump(s) at the furnace especially if the building
being heated is higher than the furnace or if there is a large
rise in the water lines between the furnace and the building
(see Fig. 15 & 16). Hot water boils at a lower temperature
when pulled uphill (because it is at a lower pressure);
therefore, hot water must be pushed uphill to ensure proper
circulation. Shut-off valves should be installed on both sides
of each pump so if it becomes necessary to repair or replace
the pump, the water can be shut off on both sides of the
pump. A screen or filter with a sediment chamber may be
installed in the line to remove foreign particles which might
be present in the water. The following guidelines must be
adhered to when installing the circulation pump(s).
A. The pump motor must be installed in a horizontal
position.
B. The junction box must be located above the pump
motor.
C. Do not run the circulation pump until the system has
been tested for leaks and filled with water.
NOTE: Be sure to follow the pump installation
instructions that are supplied with the pump if they
differ from the information contained in this
manual.
Fig. 13
When the pump is located inside the building to be
heated, a minimum of 4 feet between the water level in the
outdoor furnace and the highest point of the water line
between the furnace and the building must be maintained.
NOTE: The circulation pump(s) must be installed
in the hot supply line(s).
Fig. 14
Section 3 - Furnace Installation
Fig. 15
Fig. 16
Manual air bleeders may be installed in the high points
of the water lines where air may get trapped and cause
circulation problems. Water can be pumped to levels higher
than the furnace as long as the pump is pushing the water to
the higher level and providing there are no air leaks in the
system (see Fig. 17).
Fig. 17
Section
3
13