AERCO AM Series Boiler User Manual - Manual (Page 44)

AM Series Boilers and Water Heaters
CHAPTER 3 – INSTALLATION
Page 44 of 156 AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 OMM-0100_0B
PRI - 07/14/14
Ph.: 800-526-0288
GF-146
12. Filter: Field supplied. Install a filter or equivalent multipurpose strainer at the cold water
inlet connection of the water heater to remove system particles from older hydronic
systems and protect newer systems.
13. Flow Switch: Factory Supplied. See Section 3.11.7.
Install the heater so the gas ignition system components are protected from water (dripping,
spraying, etc.), during appliance operation for basic service of circulator replacement, valves,
and others.
3.12.2 Safety Relief Valve – Water Heaters
The water heater is supplied with a temperature & pressure safety relief valve on each module
that is factory installed. Each valve is set to 125 PSI, 210°F. If a higher or lower rated valve is
required it must be field supplied and installed.
Pipe the discharge of the safety relief valve(s) (Figure 3-8) to a suitable drain to prevent injury in
the event of pressure relief. Each relief valve must have its own discharge piping, and not be
combined with any other piping, all the way to the point of discharge into a drain. Provide piping
that is the same size as the safety relief valve outlet.
WARNING!
Never block the outlet of the safety relief valve.
NOTE
If the relief valve discharges periodically, this may be due to
thermal expansion in a closed water supply system. Contact the
water supplier or local plumbing inspector on how to correct this
situation. Do not plug the relief valve.
3.12.3 Expansion Tank in Closed Water Systems – Water Heaters
If a water heater is installed in a closed water supply system, such as one having a backflow
preventer in the cold water supply line, means shall be provided to control thermal expansion.
Contact the water supplier or local plumbing inspector on how to control this situation.
When installing an expansion tank as a means to control thermal expansion, ensure that the
expansion tank is properly sized for the water volume (See Chapter 7, header “Content of
water”) and the system volume, temperature and pressure.
CAUTION!
Undersized expansion tanks will cause system water to be lost
through the relief valve.
The expansion tank must be located as shown in Figures 3-16 and 3-17, or as per recognized
design methods. Refer to the expansion tank manufacturer instructions for additional installation
details.
3.12.4 Circulator Pump – Water Heaters
The AM Series water heaters must be fitted with a circulator pump for domestic hot water. The
water resistance to size the circulator pump to supply flow through the storage tank at the boiler
connections is shown in graph form in Figure 3-15. To electrically connect the pump, refer to
Figure 3-22 or 3-23.