Domestic Hot Water Piping - IBC DC Series Installation And Operating Instructions Manual

NOTE
See Domestic Hot Water on
page 1-27.
1-30
DC SERIES BOILERS / WATER HEATERS DC 15-95, DC 15-96, DC 20-125, DC 33-160
1.7.2 – Domestic Hot Water Piping
The domestic water piping connections are located at the bottom of the boiler
/ water heater, see Figure 30, Page 1-29. The connections are 3/4" male NPT
threads. The cold water inlet is on the right side and the hot water outlet is on the
left side.
A Pressure Relief valve with a maximum pressure setting of 150PSI and rated for
a minimum capacity of not less than the rated input of the boiler / water heater
(NOT Supplied with the boiler / water heater) must be installed within 6" of the
domestic hot water outlet. The pressure relief valve must be installed between
the boiler's outlet and any isolation valve so as to ensure the pressure relief valve
cannot be isolated by closing a valve. A valve kit designed for this purpose is
recommended to reduce installation time and reduce the space required.
If required by local code, a field-supplied Domestic Hot Water Thermostatic
Mixing Valve can be installed on the outlet of the DC Series boiler / water heater
to prevent excessively hot water from reaching a faucet if the boiler / water
heater is used in a high temperature heating system. If the boiler / water heater
is being used to heat a low temperature heating system like a radiant floor at
temperatures at or below 120°F/49°C then the thermostatic mixing valve may not
be needed.
If the boiler / water heater installation is only using the space heating portion of
the heat exchanger and not using the Domestic Hot Water portion of the heat
exchanger, then the mixing valve and the Temperature and Pressure Relief valve
need not be installed.
Do not cap off the hot and cold piping connections if they are not being
used.
The DC Series boilers / water heaters can be connected to the pressurized 1/2"
or larger domestic cold water supply piping and the domestic hot water piping
in the home. The minimum domestic water pressure required is 40PSI and
recommended to be 50PSI or higher. Generating domestic hot water with a water
pressure lower than 40PSI will reduce the amount of hot water generated and will
increase the risk of scaling in the heat exchanger.
The domestic water piping must be installed with isolation valves and flushing
taps installed on both the cold and hot domestic connections.
Thermal expansion of the water in the domestic hot water piping and boiler
/ water heater can cause excessive pressures to build in the piping system.
This can cause the pressure relief valve to discharge on a regular basis. This
condition must be prevented with the installation of a properly sized and installed
domestic water expansion tank or other device designed for the purpose.
INSTALLATION AND OPERATION INSTRUCTIONS