Navien NFC-250/175H, Руководство по установке, Страница: 42 / 151

42 Installing the System Piping
3.6.9 System Application - External Recirculation with HotButton and NaviCirc
External Recirculation Mode
For best performance, select the manual option in the External recirculation DHW recirculation mode.
Note
Combi pre-heat is the default mode for DHW recirculation. To select external recirculation, refer to the
combi pre-heat and external recirculation sections in "11.5.3 Setting the DHW Operation" on page
114 for details.
N
A/H
DHW
PRI
L
N
L
N
L
N
L
N
L
Z3
Z2
Z1
SUPPLY
TEMPERATURE SENSOR
RETURN OUTDOOR T/S_ZONE3
R W C
T/S_ZONE2
R W C
T/S_ZONE1
R W C
AC24VN
AC24VL
lLWCO
R
W
C
T/S_Recir
COM
NO
NC
ZONE_V/V3
COM
NO
NC
ZONE_V/V2
COM
NO
NC
ZONE_V/V1
N
A/H
DHW
PRI
L
N
L
N
L
N
L
N
L
Z3
Z2
Z1
SUPPLY
TEMPERATURE SENSOR
RETURN OUTDOOR T/S_ZONE3
R
W
C
T/S_ZONE2
R
W
C
T/S_ZONE1
R
W
C
AC24VN
AC24VL
lLWCO
R
W
C
T/S_Recir
COM
NO
NC
ZONE_V/V3
COM
* Recirculation
Pump
Wired
HotButton
Pump
Ground
Wired
HotButton
NaviCirc
(Sold Separately)
DHW Supply
Return Water City Water Supply
Check
Valve
Recirculation
Pump
(max. 2.5 A)
Wired
HotButton
* A Taco 008-BC6 or Grundfos 15-42 BUC7 (or equivalent) circulation pump is recommended for use with the NFC-H boiler and
DHW recirculation systems.
* When using the external recirculation mode, observe the following maximum recirculation pipe lengths including fittings ( 3 /
4
”
pipe is recommended). Lengths in excess of these limits will require a larger recirculation pump.
Maximum Pipe Lengths
Pipe Diameter
1
/
2
"
3
/
4
"
Maximum Pipe Length 100 ft (30 m) 400 ft (120 m)
Note
●
To use HotButton mode, install a HotButton and recirculation pump.
●
Install the NaviCirc recirculation valve to the faucet furthest from the NFC-H boiler.
●
If installed in close proximity to the boiler, faucets further down the supply line will take longer to
receive hot water.