A.O. Smith T-H3M-DV Installation Manual And Owner's Manual page 30

Diagrammatic layout of radiant heating and domestic water heater per Mass code
All water piping should be insulated
in accordance with 780 CMR
(Massachusetts energy code)
Automatic tempering device
must be installed below
the top of the water heater
as per manufacturer's
recommendations
Tempered water to
Piping loop
plumbing fixtures. Must
between water
meet temperature
heater and fan
requirements of 248 CMR
coil shall be in
compliance with
248 CMR
Thermostatic mixing valve
Heating Coil
(used with air-handler)
System installed with reverse
acting aquastat to shut off fan.
Suggested but not required by
248 CMR
50'-0" maximum distance from
water heater to fan coil
(Developed length) Not including
coil in heating unit
The recirculation pump is to provide no less than 2 GPM (7.5 L/min) and no more than 4 GPM (15 L/min)
through each activated unit in the system.
• Priority Control Devices such as a flow switch, an Aquastat or other
NOTICE
electronic controller can be used to prioritize the domestic water system over
the heating system
• Follow all local codes, or in the absence of local codes, follow the most recent
edition of the National Standard Code, ANSI Z21103
• This illustration is a concept design only The reference to the 1/8
in check is only for the State of Massachusetts There are a wide variety
of variations to the application of controls and equipment presented
Designers must add all necessary safety and auxiliary equipment to conform
to code requirements and design practice For more details, contact the
manufacturer
-Dual-purpose hot water heating-
(Domestic and Space Heating):
Cold water supply
Apply correct thermal
Shutoff
expansion tank-size
valve
per application
Pressure
gauge
Check valves
Shutoff valves
Check valve
Shutoff valves
NSF-61 product
approved pump
Electronically controlled
pump timer. Activates
every 6 hours for 60
seconds Wire to
product approved pump
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Page
Installation Manual
Check valve will have
1/8-inch hole drilling
in clapper optional
Atmospheric
vacuum
breaker
Drain Water
Hot water
plug filter
supply and
return to
Ball
heating coil
Valve
Isolation
Valve
T-handle gas shutoff valve
An approved temperature and pressure
relief valve. Tie to location approved by
local codes and must meet BTU rating of
water heater model used
Installation
3-inch gas exhaust
vent (Discharge must
comply with local and
state codes) Cannot
be common vented
with other appliances
Unions
120 VAC
switch or
outlet
hole
th