About the Boiler 35
3.6.7 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 "11.3.4 Setting the DHW Operation" on page 90 for details.
N
A/H
DHW
PRI
L
N
L
N
L
N
L
N
L
Z3
Z2
Z1
AC24VN
AC24VL
lLWCO
R
W
C
T/S_D
WH
R
W
C
R
W
C
T/
S_
CH_
ZO
NE
1
T/S
_Z
O
NE
2
SUPPLY
TEMPERATURE SENSOR
RETURN
OUTDOOR
T/S_ZONE3
R
W
C
AC24VN
AC24VL
lLWCO
R
W
C
R
W
C
R
W
C
T/S_CH_ZONE1
T/S_ZONE2
SUPPLY
TEMPERATURE SENSOR
RETURN
OUTDOOR
T/S_ZONE3
R
W
C
T/S_Recir.P
N
A/H
DHW
PRI
L
N
L
N
L
N
L
N
L
Z3
Z2
Z1
Recirculation pump
(max. 2.5 A)
* Recirculation Pump
Wired
HotButton
Wired
HotButton
Pump Ground
NaviCirc
(Sold Separately)
DHW Supply
Return Water
City Water Supply
Check
Valve
Recirculation
Pump
(max. 2.5A)
Wired
HotButton
* A Taco 008-BC6 or Grundfos 15-42 BUC7 (or equivalent) circulation pump is recommended for use with the NFC 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 Equivalent Copper 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 boiler.
●
If installed in close proximity to the boiler, faucets further down the supply line will take longer to receive hot water.
Summary of Contents for NFC-175
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