Bradford White FT Series Quick guide

Cascade Instructions
WARNING
If the information in this manual is not
followed exactly, a re or explosion may
result causing property damage, personal
injury or loss of life.
Do not store or use gasoline or other
ammable vapors and liquids in the vicinity of
this or any other appliance.
WHAT TO DO IF YOU SMELL GAS
• Do not try to light any appliance.
• Do not touch any electrical switch; do not
use any phone in your building.
• Immediately call your gas supplier from a
nearby phone. Follow the gas supplier's
instructions.
• If you cannot reach your gas supplier, call
the re department.
Installation and service must be performed
by a qualied installer, service agency, or gas
supplier.
FOR YOUR SAFETY: This product must be installed and serviced by a professional service technician,
qualied in hot water boiler installation and maintenance. Improper installation and/or operation could create
carbon monoxide gas in ue gases which could cause serious injury, property damage, or death. Improper
installation and/or operation will void the warranty.
AVERTISSEMENT
Assurez-vous de bien suivres les instructions
données dans cette notice pour réduire au
minimum le risque d’incendie ou d’explosion
ou pour éviter tout dommage matériel, toute
blessure ou la mort.
Ne pas entreposer ni utiliser d’essence ou ni
d’autres vapeurs ou liquides inammables dans
le à proximité de cet appareil ou de tout autre
appareil.
QUE FAIRE SI VOUS SENTEZ UNE ODEUR DE
GAZ:
• Ne pas tenter d’allumer d’appareils.
• Ne touchez à aucun interrupteur. Ne pas vous servir
des téléphones dans le bâtiment où vous vous
trovez.
• Appelez immédiatement votre fournisseur de
gaz depuis un voisin. Suivez les instructions
du fournisseur.
• Si vous ne pouvez rejoindre le fournisseur de
gaz, appelez le sservice des incendies.
L’installation et l’entretien doivent être assurés par
un installateur ou un service d’entretien qualié
ou par le fournisseur de gaz.
Installation and Cascade Instruction Manual
FTFT SERIESSERIES
Wall-hung Modulating Condensing
Gas Boiler (includes optional Floor
stand Accessory Information)
Models: FTHW399NX, FTHW301NX
• Natural Gas (NG)
Factory Conguration
• Propane Gas (LP)
Field-Convertible

Page 2
SECTION 1 General Information .................................................. 3
1.A General Plumbing Connection Guidelines ................................. 3
1.B Pipe Sizing for system and common supply &
return headers in Cascade Systems .......................................... 3
1.C Product Flow Paths and Characteristics .................................... 4
1.C.1 Central Heating ow. Boiler Heating Mode ....................... 4
1.D Miscellaneous Wiring ................................................................. 5
SECTION 2 Piping and Wiring Diagrams..................................... 6
2.A Piping and Wiring Diagrams for FTHW301/399NX boilers ........ 6
SECTION 3 Cascade Communications
(cascade cable)........................................................ 26
3.A Cascade Kit Content and Instructions ...................................... 26
3.B Wiring Connections for Cascade ............................................. 26
SECTION 4 The Control Display................................................. 30
4.A The Control Display ................................................................. 30
4.B The LCD ................................................................................... 31
SECTION 5 Cascade Programming ........................................... 32
5.A Programming a Cascade System ............................................ 32
5.B The Cascade CH Function for Set Point Operation ................. 33
5.C Outdoor Reset Operation ......................................................... 34
5.D Domestic Hot Water ‘Storage Mode’ for Cascade System ...... 34
5.E ‘L-TT or motorized mixing valve Mode’ for Cascade System ... 35
5.F Cascade System Error Codes ................................................. 36
Table of Contents

Page 3
SECTION 1 General Information.
1.A General Plumbing Connection Guidelines
1.B Pipe Sizing for system and common supply & return headers in Cascade Systems
Multiple FTHW Series boilers can be connected via a cascade communication cable to create a bank of boilers
that work in tandem. Up to 4 boilers can be controlled by a “Leader” FTHW Series boiler with the others acting as
“Followers”.
NOTES: Use piping diameters as per Table based on your maximum design delta T. Non-adherence to these
sizing guidelines may result in premature boiler failure and resulting problems are NOT covered by
product warranty.
For FTHW301/399NX boilers, use 1-1/2" near boiler piping with a combined equivalent length not to
exceed 10ft to the supply & return headers. Use 2" piping for longer runs.
An optional purge station is not needed for FTHW301/399NX models if the system piping is above the
boilers.
Use both thread tape and pipe dope to connect to the 1½" or 2" CH supply and return.
• Pipe material must be suitable to meet local codes and industry standards.
• The pipe must be cleaned and without blemish before any connections are made.
• Do not apply a torch within 12" of the top or bottom connections of the boiler. Doing so could damage the
boiler. Such damages ARE NOT covered by product warranty.
• Isolation (shuto󰀨 valves) should be used to ease future service.
• All piping should be insulated.
WARNING
Do not use FTHW Series units on common vents. Each unit must have its own supply and exhaust vents.
CAUTION
Use piping diameters as per Table based on your maximum design delta T. Non-adherence to these sizing
guidelines may result in premature boiler failure and resulting problems are NOT covered by product
warranty.
No of Boiler 301 399 ΔT=25F default ΔT=35F ΔT=45F
2
2 0 2-1/2" 2" 2"
1 1 3" 2-1/2" 2"
0 2 3" 2-1/2" 2"
3
3 0 3" 2-1/2" 2"
2 1 3" 2-1/2" 2"
1 2 3-1/2" 3" 2-1/2"
0 3 3-1/2" 3" 2-1/2"
4
4 0 3-1/2" 3" 3"
3 1 3-1/2" 3" 3"
2 2 3-1/2" 3" 3"
1 3 4" 3-1/2" 3"
0 4 4" 3-1/2" 3"

Page 4
1.C Product Flow Paths and Characteristics
1.C.1 Central Heating ow. Boiler Heating Mode.
Figure 1 - CH circulation
CH Supply
CH Supply
CH Return
CH Return
VentCombustion Air
GAS INPUT
GAS INPUT
This boiler has top and bottom return and supply water connections. Place the combo brass adaptor tting on the
upper left supply connection. Use at least one of the CH return and CH supply connections. Cap o󰀨 any other
connections that will not be used. Refer to Boiler Installation Manual for detailed boiler installation instructions.
Note that the boiler has top and bottom gas connections. Make sure to install a cap on the opposite gas connection
when installing the gas line to the appliance.

Page 5
1.D Miscellaneous Wiring
Figure 2 - Field Connections for boiler

Page 6
SECTION 2 Piping and Wiring Diagrams
2.A Piping and Wiring Diagrams for FTHW301/399NX boilers
Figure 3 - FT-301/399 Primary Secondary with zone valves and indirect

Page 7
Low Water
Cutoff
(Factory Jumper Installed)
Outdoor Sensor
(18 Gauge Wire)
Boiler Pump
(14 Gauge Wire)
System
Pump
(14 Gauge Wire)
(14 Gauge Wire)
POWER TO 24V
TRANSFORMER
(14 Gauge Wire)
END
SW N/O C N/O
ZONE 1
1 2 3 4
ZONE 1
1 2 3 4
ZONE 1
1 2 3 4
ZONE 1
1 2 3 4
FUSE (3 AMP MAX)
ZVC 404
FOUR ZONE ZONE VALVE
CONTROL
WITH OPTIONAL PRIORITY
POWER IN T T
24 VAC
INPUT
MODE
NORMAL RESET
ZONE 1
T T
ZONE 2
T T
ZONE 3
T T
ZONE 4
ZONE 4 PRIORITY
OFF
ON
THERMOSTAT THERMOSTAT THERMOSTAT
DRY
CONTACTS
2 WIRE ZONE VALVE
(NO END SWICTH)
JUMPER
3&4
1
2
3
3 WIRE ZONE VALVE 3 WIRE ZONE VALVE
MOTOR END
SW.
Line Voltage Terminals Low Voltage Terminals Low Voltage Terminals
Generic Zone Valve Controller
DHW Pump
(14 Gauge Wire)
DHW
Temperature
Sensor or
Aquastat
(18 Gauge Wire)

Page 8
Figure 4 - FT-301/399 with indirect and high / low temp zones
2.A Piping and Wiring Diagrams for FTHW301/399NX boilers

Page 9
Low Water
Cutoff
(Factory Jumper Installed)
DHW
Temperature
Sensor or
Aquastat
(18 Gauge Wire)
Outdoor
Sensor
(18 Gauge Wire)
(14 Gauge Wire)
POWER TO 24V
TRANSFORMER
(14 Gauge Wire)
Line Voltage Terminals Low Voltage Terminals Low Voltage Terminals
INPUT
FOUR ZONE SWITCHING RELAY
WITH OPTIONAL PRIORITY
SLAVE
MASTER
ZONE 4
PRIORITY
ON
OFF
POWER
HI TEMP
120 VOLT CIRCULATORS
MID TEMP
LO TEMP
ZR
ZC
X X
END SWITCH
FUSE 1 AMP
1 2 3 4
RESET NORMAL
PLUG-IN CARDS
LO TEMP MID TEMP HI TEMP
T'STATS
120 VAC INPUT
P1P2P3
Generic Pump Controller
Boiler
Pump
(14 Gauge Wire)
DHW Pump
(14 Gauge Wire)
L-TT Pump
(14 Gauge Wire)
70
TT2
Mixing
Valve L-TT temp
Sensor
(18 Gauge Wire)

Page 10
Figure 5 - Multiple - FT-301/399 with Low Loss Header
2.A Piping and Wiring Diagrams for FTHW301/399NX boilers

Page 11
Low Water
Cutoff
(Factory Jumper Installed)
Cascade System Sensor
(18 Gauge Wire)
Outdoor Sensor
(18 Gauge Wire)
(14 Gauge Wire)
POWER TO 24V
TRANSFORMER
(14 Gauge Wire)
Low Water
Cutoff
(Factory Jumper Installed)
(14 Gauge Wire)
POWER TO 24V
TRANSFORMER
(14 Gauge Wire)
Boiler 1 (Lead)
Boiler 2 (Follow)
Line Voltage Terminals Low Voltage Terminals Low Voltage Terminals Line Voltage Terminals Low Voltage Terminals Low Voltage Terminals
INPUT
FOUR ZONE SWITCHING RELAY
WITH OPTIONAL PRIORITY
SLAVE
MASTER
ZONE 4
PRIORITY
ON
OFF
POWER
HI TEMP
120 VOLT CIRCULATORS
MID TEMP
LO TEMP
ZR
ZC
X X END SWITCH
FUSE 1 AMP
1 2 3 4
RESET NORMAL
PLUG-IN CARDS
LO TEMP MID TEMP HI TEMP
T'STATS
120 VAC INPUT
P2P2-1P2-2
Generic Pump Controller
Boiler Pump
(14 Gauge Wire)
Boiler Pump
(14 Gauge Wire)
Low Water
Cutoff
(Factory Jumper Installed)
(14 Gauge Wire)
POWER TO 24V
TRANSFORMER
(14 Gauge Wire)
Boiler 3 (Follow)
Line Voltage Terminals Low Voltage Terminals Low Voltage Terminals
Boiler Pump
(14 Gauge Wire)

Page 12
Figure 6 - Three FT-301/399s Heating Only models, cascaded, Retro replacement
2.A Piping and Wiring Diagrams for FTHW301/399NX boilers

Page 13
Low Water
Cutoff
(Factory Jumper Installed)
Cascade System Sensor
(18 Gauge Wire)
Outdoor Sensor
(18 Gauge Wire)
(14 Gauge Wire)
POWER TO 24V
TRANSFORMER
(14 Gauge Wire)
Low Water
Cutoff
(Factory Jumper Installed)
(14 Gauge Wire)
POWER TO 24V
TRANSFORMER
(14 Gauge Wire)
Boiler 1 (Lead)
Boiler 2 (Follow)
Line Voltage Terminals Low Voltage Terminals Low Voltage Terminals Line Voltage Terminals Low Voltage Terminals Low Voltage Terminals
INPUT
FOUR ZONE SWITCHING RELAY
WITH OPTIONAL PRIORITY
SLAVE
MASTER
ZONE 4
PRIORITY
ON
OFF
POWER
HI TEMP
120 VOLT CIRCULATORS
MID TEMP
LO TEMP
ZR
ZC
X X END SWITCH
FUSE 1 AMP
1 2 3 4
RESET NORMAL
PLUG-IN CARDS
LO TEMP MID TEMP HI TEMP
T'STATS
120 VAC INPUT
P2P2-1P2-2
Generic Pump Controller
Boiler Pump
(14 Gauge Wire)
Boiler Pump
(14 Gauge Wire)
Low Water
Cutoff
(Factory Jumper Installed)
(14 Gauge Wire)
POWER TO 24V
TRANSFORMER
(14 Gauge Wire)
Boiler 3 (Follow)
Line Voltage Terminals Low Voltage Terminals Low Voltage Terminals
Boiler Pump
(14 Gauge Wire)

Page 14
Figure 7 - Three FT-301/399s Heating Only models, cascaded, Retro Replacement Option 2
2.A Piping and Wiring Diagrams for FTHW301/399NX boilers

Page 15
Low Water
Cutoff
(Factory Jumper Installed)
Cascade System Sensor
(18 Gauge Wire)
Outdoor Sensor
(18 Gauge Wire)
(14 Gauge Wire)
POWER TO 24V
TRANSFORMER
(14 Gauge Wire)
Low Water
Cutoff
(Factory Jumper Installed)
(14 Gauge Wire)
POWER TO 24V
TRANSFORMER
(14 Gauge Wire)
Boiler 1 (Lead)
Boiler 2 (Follow)
Line Voltage Terminals Low Voltage Terminals Low Voltage Terminals Line Voltage Terminals Low Voltage Terminals Low Voltage Terminals
INPUT
FOUR ZONE SWITCHING RELAY
WITH OPTIONAL PRIORITY
SLAVE
MASTER
ZONE 4
PRIORITY
ON
OFF
POWER
HI TEMP
120 VOLT CIRCULATORS
MID TEMP
LO TEMP
ZR
ZC
X X END SWITCH
FUSE 1 AMP
1 2 3 4
RESET NORMAL
PLUG-IN CARDS
LO TEMP MID TEMP HI TEMP
T'STATS
120 VAC INPUT
P2P2-1P2-2
Generic Pump Controller
Boiler Pump
(14 Gauge Wire)
Boiler Pump
(14 Gauge Wire)
Low Water
Cutoff
(Factory Jumper Installed)
(14 Gauge Wire)
POWER TO 24V
TRANSFORMER
(14 Gauge Wire)
Boiler 3 (Follow)
Line Voltage Terminals Low Voltage Terminals Low Voltage Terminals
Boiler Pump
(14 Gauge Wire)

Page 16
Figure 8 -
2.A Piping and Wiring Diagrams for FTHW301/399NX boilers

Page 17
Low Water
Cutoff
(Factory Jumper Installed)
Cascade System Sensor
(18 Gauge Wire)
Outdoor
Sensor
(18 Gauge Wire)
(14 Gauge Wire)
POWER TO 24V
TRANSFORMER
(14 Gauge Wire)
Low Water
Cutoff
(Factory Jumper Installed)
(14 Gauge Wire)
POWER TO 24V
TRANSFORMER
(14 Gauge Wire)
Boiler 1 (Lead)
Boiler 2 (Follow)
Line Voltage Terminals Low Voltage Terminals Low Voltage Terminals Line Voltage Terminals Low Voltage Terminals Low Voltage Terminals
INPUT
FOUR ZONE SWITCHING RELAY
WITH OPTIONAL PRIORITY
SLAVE
MASTER
ZONE 4
PRIORITY
ON
OFF
POWER
HI TEMP
120 VOLT CIRCULATORS
MID TEMP
LO TEMP
ZR
ZC
X X END SWITCH
FUSE 1 AMP
1 2 3 4
RESET NORMAL
PLUG-IN CARDS
LO TEMP MID TEMP HI TEMP
T'STATS
120 VAC INPUT
P2P2-1P2-2
Generic Pump Controller
Boiler Pump
(14 Gauge Wire)
Boiler Pump
(14 Gauge Wire)
Low Water
Cutoff
(Factory Jumper Installed)
(14 Gauge Wire)
POWER TO 24V
TRANSFORMER
(14 Gauge Wire)
Boiler 3 (Follow)
Line Voltage Terminals Low Voltage Terminals Low Voltage Terminals
Boiler Pump
(14 Gauge Wire)
Low Water
Cutoff
(Factory Jumper Installed)
(14 Gauge Wire)
POWER TO 24V
TRANSFORMER
(14 Gauge Wire)
Boiler 4 (Follow)
Line Voltage Terminals Low Voltage Terminals Low Voltage Terminals
Boiler Pump
(14 Gauge Wire) R B W
DHW Aquastat Stage1
(18 Gauge Wire)
DHW Aquastat Stage2
(18 Gauge Wire)
DHW Pump
(14 Gauge Wire)
DHW Pump
(14 Gauge Wire)

Page 18
Figure 9 - Two FT-301/399s Heating Only models, cascaded with pumps
2.A Piping and Wiring Diagrams for FTHW301/399NX boilers

Page 19
15b.

Page 20
Figure 10 - Multiple - FT-301/399 with Floor Stand
2.A Piping and Wiring Diagrams for FTHW301/399NX boilers