VX 399 Gas-Fired, Floor Mounted Modulating Condensing Boiler


The VX 399 Floor Mounted Condensing Boiler features:

  •  96% Thermal Efficiency
  • CSD-1 Compliant with

- Manual Reset Low Water Cut Off
- High Limit Manual Reset

  • 5:1 Turn Down Ratio
  • Innovative Heat Exchanger

- 316L/444 Stainless Steel Fin Tube
- Vertically Positioned, Low Maintenance, Self-Cleaning
- Polypropylene Flue Collector
- 150 psi MAWP


Gas Supply

  • Top Pipe connection with built-in drip leg saves material & time

Dunkirk’s Stainless Steel Heat Exchanger

  • Patent Pending 316L/444 stainless steel fin tube
  • Vertically mounted and self-cleaning
  • ASME certified to operate in applications up to 150 psi
  • Every heat exchanger is tested up to 375 psi
  • Built-In CSD-1 Compliant

Dunkirk Quality

  • Every boiler is test-fired at the factory
  • Complete combustion test is performed and a computer printout of the results are shipped with every boiler to ensure proper commissioning

8 year Limited Manufacturer’s Warranty

  • The VX 399 heat exchanger is simply the finest ever designed and as such we provide an 8-year factory warranty coverage
  • One Year Parts Warranty 

CSD-1 Control package includes: UL listed LWCO w/Manual Reset. 

Boiler Control Module: High Temperature limit w/Manual Reset. Outdoor Temperature Sensor included. Automatic Line Voltage Intermittent Direct Spark Ignition, Modulating with a 5:1 combustion turn down ratio. 

(For multiple boiler applications - the control module can stage up to 16 boilers.) 

User Display interface: Easy programming with text display. 

Heat Exchanger: High grade 316L/444 Stainless Steel Fin Coil with Flame Sight Glass. 

Combustion: Gas Valve with Premix Venturi and Blower, Durable Stainless Steel Mesh Modulating Burner with 5:1 turn down ratio, Direct Spark Igniter and Flame Sensor. 

Electrical: Line Voltage Terminal Strip, High Voltage Junction Box and Transformer. 

Other: 50 PSI Safety Relief Valve, Boiler Drain Valve and Condensate Drain with built in trap, Leveling Legs.


(See Installation, Operation and Maintenance Manual for complete instructions)


Documents / Resources

Product Testimonials

Sorry, there are no reviews yet for this product. Would you like to leave feedback?