Installation; Electrical Supply; Dedicated Power Wiring And Breakers - A.O. Smith 100 Series Installation And Operating Manual

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. This heater is not
designed to be used in a space heating only application.
3. No boiler treatment chemicals of any kind shall be introduced
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 performed in accordance with
good engineering practice such as "ASHRAE Handbooks",
HRAI's Unified Combo Guidelines, "Hydronics Institute
Manuals", ANSI Z223.1, CSA F280, National/Provincial
Building Codes, ANSI 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 120Vac circuit.
This must be provided and identified for this purpose.
6. All piping between the water heater and the air handler or
hydronic baseboard loop must be adequately insulated 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 temperatures
than other applications. When the system is used to supply water
for Combo Heating applications, a mean such as Thermostatic
Mixing Valves at each point-of-use, must be installed to temper
the water in order to reduce scald hazard potential. See Figure
39 and Figure 40.

INSTALLATION

The heating mode may be one of the following options:
A. A fan coil/air handler. See Figure 39 (page 33).
B. A hydronic baseboard (finned tube) loop/In floor heating. See
Figure 39 (page 33).
The following is a list of requirements for the installation of option
A or B.
1. Install shut-off valves and unions so that the water heater can
be isolated from the heating module should servicing of the
water heater become necessary.
2. Install a drain valve at the lowest point of the heating loop so
that water can be drained from the heating module without
affecting the water heater.
3. If the air handler does not have a venting means at the highest
point of the piping arrangement, install an air bleed at the highest
point of the plumbing arrangement.
Important: Install a spring loaded check valve in the space
heating return line to prevent cold water from
continuously entering the water heater. Failure
to install such a valve could cause "stacking" and
cause the T&P valve to open.
HOT WATER EXPANSION TANK (OPTIONAL)
TO HOUSE
COLD SUPPLY
FIXTURE
C
M
H
MIXING
VALVE
WATER
HEATER
HOT
OUTLET
SPRING
LOADED
CHECK
VALVE
Figure 39. Typical Combo Heating Configuration
HOT WATER EXPANSION TANK (OPTIONAL)
TO HOUSE
FIXTURE
C
M
H
MIXING
VALVE
HOT
OUTLET
SPRING
LOADED
CHECK
VALVE
Figure 40. Typical Combo Heating with Hydronic Baseboards

ELECTRICAL SUPPLY

The water heaters covered in this manual require a 120 Vac, 1Ø
(single phase), 60Hz, 10 amp power supply and must also be
electrically grounded in accordance with local codes or, in the
absence of local codes, with the Canadian Electrical Code" (CSA C22.1),
Part I.
If any of the original wire as supplied with the water heater must
be replaced, it must be replaced with 105°C rated wiring or its
equivalent, except in the burner housing. In this case 200°C rated
wire must be used.

DEDICATED POWER WIRING AND BREAKERS

Dedicated power supply wires, ground wiring and dedicated circuit
breakers often prevent electrical line noise and should be considered
when installing the water heater.
33
CHECK VALVE (IF USED
REQUIRES EXPANSION TANK)
COLD
INLET
EXTERNAL
FLOW
CIRCULATOR
CONTROL
HOSE BIB
(OPTIONAL)
RETURN
SUPPLY
INTERNAL
CIRCULATOR
HANDLER
COLD SUPPLY
CHECK VALVE (IF USED
REQUIRES EXPANSION TANK)
COLD
INLET
EXTERNAL
FLOW
CIRCULATOR
CONTROL
HOSE BIB
(OPTIONAL)
SUPPLY
BASEBOARDS
DRAIN/
PURGE
VALVE
AIR
RETURN
HYDRONIC
(SERIES
CONNECTED
SHOWN)