Piping Components - Water Heaters - Watts Aerco TAG-0072 GF-146-E Operation & Maintenance Manual

AM Series Boiler & Water Heater User Manual
CHAPTER 4: INSTALLATION – PIPING
•
Indirect water heater circulating pump: Field supplied. The pump MUST be sized to
meet the specified flow requirements. Consult the indirect water heater operating guide to
determine flow characteristics for the selected product used.
•
Isolation valves: Field supplied. Full port ball valves are required. Failure to use full port
ball valves could result in a restricted flow rate through the boiler.
•
Anti-scald mixing valve: Field supplied. If the boiler is connected to an indirect
water heater for domestic hot water, this device MUST be installed.
•
Unions: Field supplied. Recommended for unit serviceability.
•
Safety relief valve. See Section 4.8.
•
LWCO (Low Water Cut-Off): A LWCO comes with every unit and must be field installed.
For more information, see Section 4.9.
•
Indirect water heaters: Field supplied. This boiler may be piped to an indirect water heater
to heat domestic hot water with the space heat transfer medium. The indirect water heater is
connected to the system supply piping. A pump controlled by the boiler's control will provide
the flow of water through the indirect water heater. The indirect water heater's temperature
will be regulated by the boiler's control. The boiler is pre-configured to control the operation
of the DHW pump with Domestic Hot Water Prioritization programming.
•
Temperature Sensor:
relocated to the system piping. For multiple unit installations using the AM Cascade
Sequencer, the cascade header temperature sensor (included) must be installed in the
system piping.
CAUTION!
It is up to the installer to ensure the minimum system flow is not at any time less than the
values in the Minimum Water Flow row in Section 11: Technical Data. If the flow is lower,
the unit automatically stops the burner.
WARNING!
The National Standard Plumbing Code, the National Plumbing Code of Canada and the
Uniform Plumbing Code limit the pressure of the heat transfer fluid to less than the minimum
working pressure of the potable water system up to 30 psi maximum. Also, the heat transfer
fluid must be water or other non-toxic fluid having a toxicity of Class 1, as listed in Clinical
Toxicology of Commercial Products, 5th Edition.
•
Filter: Field supplied. A filter or equivalent multipurpose strainer is recommended at the
return pipe of the boiler to remove system particles from older hydronic systems and protect
newer systems.
4.7 Piping Components – Water Heaters
The separate storage vessel must have a temperature and pressure relief valve installed. This
relief valve shall comply with the Standard for Relief Valves for Hot Water Supply Systems,
ANSI Z21.22 • CSA 4.4.
Water heater system piping MUST be sized considering the pressure drops of the water heater
(see figure 4-4), piping and storage tank.
Reducing the pipe size can restrict the flow rate through the water heater, causing poor system
performance. Basic steps are listed below along with illustrations on Figures 4-6 and 4-8,
which will guide you through the installation of the water heater piping.
OMM-0100_E • GF-146 • 11/15/2019
For a single unit installation, the temperature sensor must be
Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST Page 47 of 170