• Factory tested
• Easy service
• Factory-assembled cast iron section with built-in air separator assembly, including aluminized steel flue collector, swing-away burner mounting door, with refractory blanket and recessed target wall in combustion chamber
• Low draft loss
• Top access cleanout cover
• Plug-in wiring harness
• High efficiency flame-retention oil burner
• Flame retention head design
• Solenoid valve
• PSC motor
• Solid state igniter
• Rear flue outlet
• Insulated heavy gauge steel jacket
• High limit control with circulator relay
• 15 psig ASME relief valve
• Drain valve
• Barometric damper
• Siphon
• Gauge glass and guard assembly
• Pressure gauge
• Probe low water cut-off
• 7" flue connection size
• Limited lifetime warranty on heat exchanger, 3 year limited warranty on parts

williamson -thermoflo osb-4-p-s3

• Designed to operate in low temperature condensing applications
• Outdoor reset and domestic hot water priority
• Modulates with 5:1 turn-down ratio
• High grade stainless steel burner features quiet operation
• U-Control gives the power for easy set-up and maintenance, multiple set-up and zone options, system sensing recognizes system and outdoor temperatures, temperature management for up to three different set-points, control multiple boilers from a single control panel, standard screen messages provide service alerts and maintenance reminders
• 30 psi ASME relief valve
• Drain valve
• Stainless steel burner (80, 105) with woven steel fiber mesh (155, 230, 299 and 399)
• Variable speed blower assembly, Venturi mixing system with air silencer, negative pressure regulated gas valve, 50 VA transformer
• Dual scale temperature and pressure gauge, outlet water temperature sensor, inlet water temperature sensor, flue gas temperature sensor, outdoor temperature sensor
• System water temperature sensors, fully removable jacket front, adjustable boiler legs, on/off power switch, condensate trap with drain tee assembly, propane conversion orifice (all except model 80), water treatment - inhibitor and test kit
• Control module - 3.5" LCD display, 3-boiler priorities with multiple preset system configurations, color-coded removable terminal blocks, multiple boiler functionality, alarm control functionality, ignition control, high limit and modulating temperature control, low water protection, outdoor reset, ability to control any combination of 3 circulators
• PVC/CPVC/PP vent material
• 1-1/2" minimum recommended pipe size
• 1-1/4 and 1-1/2" flanges (399) taco 0013 boiler circulators

• Designed to operate in low temperature condensing applications
• Outdoor reset and domestic hot water priority
• Modulates with 5:1 turn-down ratio
• High grade stainless steel burner features quiet operation
• U-Control gives the power for easy set-up and maintenance, multiple set-up and zone options, system sensing recognizes system and outdoor temperatures, temperature management for up to three different set-points, control multiple boilers from a single control panel, standard screen messages provide service alerts and maintenance reminders
• 30 psi ASME relief valve
• Drain valve
• Stainless steel burner (80, 105) with woven steel fiber mesh (155, 230, 299 and 399)
• Variable speed blower assembly, Venturi mixing system with air silencer, negative pressure regulated gas valve, 50 VA transformer
• Dual scale temperature and pressure gauge, outlet water temperature sensor, inlet water temperature sensor, flue gas temperature sensor, outdoor temperature sensor
• System water temperature sensors, fully removable jacket front, adjustable boiler legs, on/off power switch, condensate trap with drain tee assembly, propane conversion orifice (all except model 80), water treatment - inhibitor and test kit
• Control module - 3.5" LCD display, 3-boiler priorities with multiple preset system configurations, color-coded removable terminal blocks, multiple boiler functionality, alarm control functionality, ignition control, high limit and modulating temperature control, low water protection, outdoor reset, ability to control any combination of 3 circulators
• PVC/CPVC/PP vent material
• 1-1/2" minimum recommended pipe size
• 1-1/4 and 1-1/2" flanges (399) taco 0013 boiler circulators

• Designed to operate in low temperature condensing applications
• Outdoor reset and domestic hot water priority
• Modulates with 5:1 turn-down ratio
• High grade stainless steel burner features quiet operation
• U-Control gives the power for easy set-up and maintenance, multiple set-up and zone options, system sensing recognizes system and outdoor temperatures, temperature management for up to three different set-points, control multiple boilers from a single control panel, standard screen messages provide service alerts and maintenance reminders
• 30 psi ASME relief valve
• Drain valve
• Stainless steel burner (80, 105) with woven steel fiber mesh (155, 230, 299 and 399)
• Variable speed blower assembly, Venturi mixing system with air silencer, negative pressure regulated gas valve, 50 VA transformer
• Dual scale temperature and pressure gauge, outlet water temperature sensor, inlet water temperature sensor, flue gas temperature sensor, outdoor temperature sensor
• System water temperature sensors, fully removable jacket front, adjustable boiler legs, on/off power switch, condensate trap with drain tee assembly, propane conversion orifice (all except model 80), water treatment - inhibitor and test kit
• Control module - 3.5" LCD display, 3-boiler priorities with multiple preset system configurations, color-coded removable terminal blocks, multiple boiler functionality, alarm control functionality, ignition control, high limit and modulating temperature control, low water protection, outdoor reset, ability to control any combination of 3 circulators
• PVC/CPVC/PP vent material
• 1-1/2" minimum recommended pipe size
• 1-1/4 and 1-1/2" flanges (299) taco 0014 boiler circulators

• Designed to operate in low temperature condensing applications
• Outdoor reset and domestic hot water priority
• Modulates with 5:1 turn-down ratio
• High grade stainless steel burner features quiet operation
• U-Control gives the power for easy set-up and maintenance, multiple set-up and zone options, system sensing recognizes system and outdoor temperatures, temperature management for up to three different set-points, control multiple boilers from a single control panel, standard screen messages provide service alerts and maintenance reminders
• 30 psi ASME relief valve
• Drain valve
• Stainless steel burner (80, 105) with woven steel fiber mesh (155, 230, 299 and 399)
• Variable speed blower assembly, Venturi mixing system with air silencer, negative pressure regulated gas valve, 50 VA transformer
• Dual scale temperature and pressure gauge, outlet water temperature sensor, inlet water temperature sensor, flue gas temperature sensor, outdoor temperature sensor
• System water temperature sensors, fully removable jacket front, adjustable boiler legs, on/off power switch, condensate trap with drain tee assembly, propane conversion orifice (all except model 80), water treatment - inhibitor and test kit
• Control module - 3.5" LCD display, 3-boiler priorities with multiple preset system configurations, color-coded removable terminal blocks, multiple boiler functionality, alarm control functionality, ignition control, high limit and modulating temperature control, low water protection, outdoor reset, ability to control any combination of 3 circulators
• PVC/CPVC/PP vent material
• 1-1/4" minimum recommended pipe size
• 1 and 1-1/4" flanges (155 and 230) taco 0014 boiler circulators

• Designed to operate in low temperature condensing applications
• Outdoor reset and domestic hot water priority
• Modulates with 5:1 turn-down ratio
• High grade stainless steel burner features quiet operation
• U-Control gives the power for easy set-up and maintenance, multiple set-up and zone options, system sensing recognizes system and outdoor temperatures, temperature management for up to three different set-points, control multiple boilers from a single control panel, standard screen messages provide service alerts and maintenance reminders
• 30 psi ASME relief valve
• Drain valve
• Stainless steel burner (80, 105) with woven steel fiber mesh (155, 230, 299 and 399)
• Variable speed blower assembly, Venturi mixing system with air silencer, negative pressure regulated gas valve, 50 VA transformer
• Dual scale temperature and pressure gauge, outlet water temperature sensor, inlet water temperature sensor, flue gas temperature sensor, outdoor temperature sensor
• System water temperature sensors, fully removable jacket front, adjustable boiler legs, on/off power switch, condensate trap with drain tee assembly, propane conversion orifice (all except model 80), water treatment - inhibitor and test kit
• Control module - 3.5" LCD display, 3-boiler priorities with multiple preset system configurations, color-coded removable terminal blocks, multiple boiler functionality, alarm control functionality, ignition control, high limit and modulating temperature control, low water protection, outdoor reset, ability to control any combination of 3 circulators
• PVC/CPVC/PP vent material
• 1-1/4" minimum recommended pipe size
• 1 and 1-1/4" flanges (155 and 230) taco 0014 boiler circulators

• Factory tested and assembled cast iron section assembly
• Tankless heater (P-units) or tankless opening cover plate (A-units)
• Insulated steel jacket
• Aluminized steel flue collector hood with flue cap on top outlet (convertible to rear outlet)
• Swing away burner mounting door
• Refractory blanket and target wall in combustion area
• Includes 007 circulator
• Combustion temperature controls, LWCO and circulator relay
• Electrical junction box with wiring harnesses
• Junction box cover plate with service switch
• (2) vent pipe brackets
• Pressure and temperature gauge
• 30 psi ASME pressure relief valve
• Drain valve
• Barometric damper
• 3/4" NPT temperature control
• 1-1/4" circulator flange for P-units, 1-1/2" for A-units
• Temperature ranges from 40 - 140 deg F