AM Series Boiler & Water Heater User Manual
CHAPTER 4: INSTALLATION
– PIPING
OMM-0100_E
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GF-146
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11/15/2019
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4.10 Expansion Tank and Makeup Water
Install an expansion tank. Ensure the expansion tank is properly sized for the boiler volume and
the system volume, temperature and pressure.
CAUTION!
Undersized expansion tanks will cause system water to be lost through the pressure relief
valve and cause additional makeup water to be added to the system. Eventual boiler failure
can result due to this excessive makeup water addition, compromising the functionality of the
unit.
Refer to the expansion tank manufacturer instructions for additional installation details.
Connect the expansion tank to an air separator only if the air separator is located on the suction
side (inlet) of the system circulator.
Always locate and install the system fill connection at the same location as the expansion tank
connection to the system
4.11 Circulator Heating Pump
AM Series boilers and water heaters must be
fitted with a circulator pump. The water
resistance to size the circulator pump to supply
flow through the heating system at the unit’s
connections is shown in graph form in Figure 4-3.
It is up to the installer to ensure the minimum system
flow is not at any time less than the
values in in the
Minimum Water Flow
in Section 11:
Technical Data
. If the
flow is lower, the
unit automatically stops the burner.
To connect a central heating pump on the secondary loop, see Figure 4-7, and t o
electrically connect the pump to the boiler, see Figure 5-3.
Figure 4-3: AM Series Water Side Head Pressure Loss Graph
The water heater pressure losses (see Figure 4-4) are based on potable water with a hardness
of 5 to 25 grains per gallon and a total dissolved solids not exceeding 200 ppm. Consult the
manufacturer when heating potable water exceeding these specifications.
Heating of high hardness and/or high total dissolved solids water increases the pressure drops
