Draft Controller


The JC-22D2 Draft Monitor and Controller is a microprocessor based draft controller, indicating instrument, and alarm monitor.  The JC-22D2 includes advanced control algorithms for tall stacks, multiple furnace stacks, and fast varying loads. Read more about our history and expertise in draft control on our blog "Draft Controls: Then and Now.

  • Automatic Draft Control
  • Precision Outlet Draft Control
  • Firing Rate Feedforward
  • Floating Draft Control
  • PID Draft Control
  • Automatic Damper Sequencing
  • Damper Adjustable Start Position
  • High Draft Alarm
  • Modbus Communication with RS-485 and Ethernet capability.
  • Live Data Tuning Screen

Updates Include: 

  • Modbus TCP/IP ethernet communications.
  • Color touchscreen, similar to the PCC-IV.
  • Controller depth is 4.88” for shallow panel mounting. Compare to 7” depth on the JC-22D.
  • Plug-in wiring terminals for quick controller replacement.
  • Firmware updating in the field via JCD2_Edit and USB port.
  • Up to 50 historical alarm and event messages with time/date.
  • Overview and Features
  • Application
  • Specifications
  • Documents
Overview and Features

The JC-22D2 Draft Monitor and Controller is a microprocessor based draft controller, indicating instrument, and alarm monitor. The JC-22D2 directly accepts 0-20/4-20mA draft transmitter signals, 120 VAC flame safeguard interface, and outputs a solid state switching (Triac) or 0-20/4-20mA outlet damper actuator control signal. Draft is continuously displayed using a highly visible color touchscreen.  An intuitive bar graph display and alarm message provides clear boiler draft status. All adjustments can be made directly from the faceplate of the instrument by scrolling through user friendly, English language menus. The outlet damper may be controlled in “Auto” or “Manual” mode and will automatically sequence through the purge, light-off, post-purge & burner shutdown modes in response to flame safeguard system inputs. The JC-22D2 automatically positions the outlet damper according to burner operation based on either the field selectable “Floating” or “Precise Draft” Control modes.


  • Automatic Draft Control for increased boiler efficiency and reliability.
  • Precision Outlet Draft Control for low NOx induced FGR burners.
  • Firing Rate Feedforward option is included and assures stable draft during load changes. Separate curves for up to two fuels.
  • Floating Draft Control mode is the easiest to tune. Floating Control can be used with any type of actuator or an ID Fan VSD.
  • PID Draft Control mode is included for those who prefer this type of tuning.
  • Automatic Damper Sequencing for purge, light-off, post-purge burner shutdown, and standby. Simple Flame Safeguard interface.
  • Damper Adjustable Start Position option is included for installations with excessively high draft during light-off.
  • High Draft Alarm with time stamped alarm and event history.
  • Modbus Communication with RS-485 and Ethernet capability.
  • Live Data Tuning Screen for more convenient tuning.

Uncontrolled stack draft can cause burner instability, unreliable ignition, and affect fuel-air ratio control repeatability. Burner manufacturers typically recommend draft controls be installed in applications where:

• Stack height exceeds 75 feet
• Multiple furnaces are connected to a single stack



Power Supply:           120 VAC +/-15%, 50/60 Hz, 26 V
Case Size:                   3 1/2 w x 7 9/16 h x 4 7/8 d
Enclosure Type:         NEMA 12 Faceplate, Indoor Location
Ambient Temp.:         32-131 F (0-55 C)
Displays:                     Color Touchscreen
                                      3 9/16 w x 7 5/8 h
Bargraph Range:       -1.00 to +1.00" W.C.
Alarm Setpoints:        One (1) adjustable contact with adjustable time delay


Draft Input:                4-20 mA
Firing Rate Input:      4-20mA, 0-2.3V, 0-5V, 0-10V
Discrete Input:            (5) 120 Vac, 13 mA typ/ch., opto-isolated
Actuator Feedback:    0.15 - 2.29 Vdc


Relay Outputs:        (2) SPDT, (2) SPST, 120Vac,10 A
Actuator Outputs:   (2) 24-120 Vac, 2A fuse, opto-isolated
Network:                  USB: non-isolated, JC_D3Edit config. & Firmware Flashing | RS485: Isolated, 4.8 - 57.6 kbaud, Modbus RTU | Ethernet: 10/100 Nb/s, Modbus/TCP


Draft Controller Specification

Draft Controller Instruction Manual

Draft Controller Cutsheet

Draft Controller Brochure

Draft Controller Wiring Diagram

Model ‘D’ Versus Model ‘D2’ Wiring Comparison