35
6
Hydronic piping
(continued)
Installation & Service Manual
Near boiler piping components
1. Boiler system piping:
Boiler system piping MUST be sized per the pipe
requirements listed in Table 6A. Reducing the pipe size
can restrict the flow rate through the boiler, causing
inadvertent high limit shutdowns and poor system
performance. Flow rates are based on 20 feet of piping,
4 - 90° elbows, and 2 - fully ported ball valves.
2. Boiler circulating pump:
Field supplied. Must be sized to meet the minimum
requirements listed in Table 6A on page 38.
3. Domestic hot water circulating pump:
Field supplied. The pump MUST be sized to meet
the specified minimum flow requirements listed in
Table 6A. Consult the indirect water heater operating
guide to determine flow characteristics for the selected
product
used.
4. Boiler
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.
5. Check
valves:
Field supplied. Check valves are recommended for
installation as shown in FIG.’s 6-4 through 6-6. Failure
to install check valves could result in a reverse flow
condition during pump(s) off cycle.
6. Domestic indirect hot water 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.
7. Anti-scald mixing valve:
Field supplied. For use when utilizing the DHW option.
An anti-scald mixing valve is recommended when storing
domestic hot water above 115°F.
8. Unions:
Field supplied. Recommended for unit serviceability.
9. Temperature and pressure gauge:
Factory supplied. The temperature and pressure gauge is
shipped loose. It is the responsibility of the contractor to
install the temperature and pressure gauge on the boiler
water
outlet.
10. Pressure relief valve:
Factory supplied. The pressure relief valve is sized to
ASME
specifications.
11. Boiler purge valve:
Field supplied. The boiler purge valve is used to
remove entrapped air from the heat exchanger during
start-up.
12. System temperature sensor (optional):
The manufacturer offers a system temperature sensor
(KIT3078). The sensor is to be installed in the heating loop
downstream from the boiler hot water piping and
heating loop junction. Typically the sensor will be
located far enough downstream to sense system diluted
water
temperature.
13. Indirect water heaters:
The Cadet heating boiler may be piped to an indirect
water heater to heat domestic hot water with the space
heat transfer medium. As depicted in the piping
diagrams on page 39 thru 41, the space heating piping
will branch off to flow the space heat transfer medium
through a heat exchanger coil inside the indirect water
heater.
The Cadet heating boiler is pre-configured to control
the operation of the DHW pump with Domestic Hot
Water Prioritization programming. The DHW
Programming is designed to control and balance the
space heating demand by switching between DHW and
space
heating.
The manufacturer offers a series of indirect water heaters
called the Squire. The Squire features a stainless steel
vessel with a single wall stainless steel heat exchanger.
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, 5
th
Edition.
14. Y-Strainer:
Field supplied. A Y-strainer or equivalent multipurpose
strainer is recommended at the inlet of the heat exchanger
to remove system particles from older hydronic systems and
protect newer systems.