John Wood Noritz Concentric Vent - NR98-DVC (N-0751M) - Manual (Page 19)

19
11.
Plumbing Applications
Recirculation System
Combination Potable Water and Space Heating System
Cold Water Supply
Isolation
Kit(*4)
Gas Supply
Aquastat(*3)
Pump Control Signal(*2)
Relay for Pump
(if larger than 85 Watts)
Hot Water
Optional 30-38L (8-10 Gallon)
Storage Tank
(To alleviate cold water sandwich)
Globe
Valve
Pump(*1)
Expansion Tank
(Install according
to local code)
Fixtures
Hot Water Return
R
B
W
Pump
120VCA
105
Neutral
Ground
Live
S
Isolation
Kit(*1)
Gas Supply
Backflow Preventer
(optional)
Check
Valve(*3)
Cold Water
Supply
Mixing Valve(*5) Hot Water
Pump(*2)
Flow Switch(*4)
Fixtures
Air Handler
Use Honeywell Aquastat
(Model L6006A or L6006C)
Aquastat Wiring
Optional
Expansion Tank(*6)
Notes:
Notes:
1. Noritz recommends the use of an Isolation Kit with
the installation.
These kits include an integrated shut-off and serv-
ice valve with unions and a pressure relief valve.
2. Size the pump to provide a maximum of 11.3 L/min.
(3 GPM) with a head pressure equal to the loss
through the water heater and Air Handler.
3. Check valve required if it is not included with the
pump.
4. Set the flow switch to deactivate the Air Handler when
the domestic hot water flow reaches 11.3 L/min. (3 GPM).
Adjust as necessary to prevent cycling.
5. If the system requires water for space heating at
a higher temperature than for other uses, means
such a mixing valve shall be provided to temper
the water for the other uses to help prevent scald
-ing.
6. Expansion tank required if a backflow preventer is
installed.
1. Size the pump to provide a maximum of 7.5 L/min.
(2 GPM) through the system at 3m (10 ft) of head
plus piping losses.
Adjust the flow using a globe valve and verify the
flow rate with the maintenance monitors.
2. Pump Control Signal is the preferred method
to control the recirculation pump.
For pumps larger than 85W, a relay connection must
be used. If the Pump Control Signal is not used,
an Aquastat may be used to control the pump.
3. Use an Aquastat if the water heater is not control-
ling the pump.
Set the Aquastat to 5
°C (10°F) below the set
output temperature.
4. Noritz recommends the use of an Isolation Kit
with the installation.
These kits include an integrated shut-off and serv-
ice valve with unions and a pressure relief valve.
NORITZ
Tankless Gas
Water Heater
NORITZ
Tankless Gas
Water Heater