John Wood Oil-Fired User Manual
Page 20
This section serves as a guide for the installation and use of
“Combo” heating systems utilizing a domestic water heater
that has been specifically approved for such use. It is writ-
ten for those knowledgeable in the required trades and pro-
fessionals involved in the design and installation of Combo
Heating Systems.
It is the responsibility of the installer/designer to follow
all applicable codes to ensure the effectiveness and
safety of the installation.
Read Before Proceeding
The following requirements must be met for the installation
of Combo Heating Systems:
1. All components used for the distribution of water in the
heating loop must be suitable for potable water. These
include all piping, fittings, solder and fluxes, pumps for
circulation of water, valves, etc.
2. The water heater must not be connected to a hydronic
heating system that has been used previously.
3. No boiler treatment chemicals of any kind shall be intro-
duced into the system.
4. The Combo System components must be selected and
sized to meet and maintain the total calculated demands
for both domestic service hot water and space heating
requirement. The sizing and installation must be per-
formed in accordance with good engineering practice
such as “ASHRAE Handbooks”, HRAI, “Hydronics
Institute Manuals”, CSA B139-04, NFPA 31, ANSI
Z223.1, CSA F280, National/Provincial Building
Codes, CSA C22.1, ANSI/NFPA 70, CSA B51 and/or
codes having jurisdiction.
5. The air handler (fan coil) and/or the circulating pump in
a baseboard hydronic loop will require a dedicated 120V
circuit. This must be provided and identified for this pur-
pose.
6. All piping between the water heater and the air handler
or hydronic baseboard loop must be adequately insulat-
ed to reduce heat loss.
7. If the local jurisdiction requires a back-flow preventer in
the cold water line, an expansion tank of adequate size
must be installed.
8. “Combo” Heating Systems require higher water temper-
atures than other applications. When the system is used
to supply water for Combo Heating applications, a
means, such as mixing valve, must be installed to tem-
per the water in order to reduce scald hazard potential
(see Figures 14, 15 & 16).
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VI) COMBO HEATING
WARNING:
Keep the area around the heater clear and
unobstructed.
CAUTION:
Keep safety your first priority. Take all pre-
cautions to avoid creating a fire, health or
safety hazard.