21
Recirculation
Dual-purpose Hot Water Heating with T-D2-IN / 510 Model Only
(Domestic and Space Heating):
Diagramatic layout of Radiant Heating and Domestic Water Heater .
The recirculation pump is to provide no less than 7 .5 L/min (2 GPM (US))
and no more than 15 L/min (4 GPM (US)) through each activated unit in the system .
Note
:
•
Priority Control Devices
such as a flow switch, an Aquastat or other electronic controller can be used to prioritize the
domestic water system over the heating system .
•
Follow all local codes .
•
This illustration is a concept design only . There are a wide variety of variations to the application of controls and equip-
ment presented . Designers must add all necessary safety and auxiliary equipment to conform to code requirements and
design practice . For more details, contact the manufacturer .
•
The recirculation pump is to be
controlled by:
•
Dual-set aquastat
(recommended w/timer)
OR
•
“Pump Control Mode” (T-D2-IN
/ 510 Models only) . Refer to
pg . 18 .
•
The recirculation pump is to
provide no less than 7 .5 L/min
(2 GPM (US)) and no more than
15 L/min (4 GPM (US)) through
each activated unit in the system .
120 VAC
switch or
outlet
Hot water outlet
Readily accessible
T-handle gas shut-off valve
Check valve
Electronically controlled pump timer .
Activates every 6 hours for 60 seconds .
Wire to product approved pump .
The T-D2-IN / 510 built in Pump control
may also be used to control pump .
Heating Coil
(used with air-handler)
Cold water supply
4" gas exhaust vent
(Discharge must comply
with local and state codes) .
Cannot be common vented
with other appliances .
An approved temperature and pressure relied valve,
tie to location approved by local codes and Must
meet BTU rating of water heater model used .
Check valve will have
1/8" hole drilling in
clapper optional .
Atmospheric
vacuum breaker
Shut-off
valve
Apply correct thermal
expansion tank-size per
application .
Shut-off valves
Shut-off valves
Check valves
Cold water inlet
Gas inlet
Water
filter
Drain
plug
Thermostatic mixing valve
Hot water
supply and
return to
heating coil
System installed with reverse acting
aquastat to shut off fan
50’-0” maximum distance from water
heater to fan coil (Developed length) Not
including coil in heating unit .
NSF-61 product
approved pump
Automatic tempering device
must be installed below the
top of the water heater as per
manufacturer’s recommendations .
Piping loop
between water
heater and fan
coil
Tempered water to plumbing
fixtures. Follow local code.
T
P
Pressure
gauge
Unions
Hot water outlet
Cold water inlet
Gas inlet
Unions
Ball valves
Gas supply
Expansion tank
Cold water
inlet
Y-Strainer
Check valve
Pressure
relief valve
Check valve
Air
separator
Recirculation
pump
Hot water outlet to fixtures
Air vent
S
Unions
Ball
valve
