Controlled Power
Proven draft control for gas and solid fuel
Set once, right for the application-specific chimney. The installer dials in draft inducer speed at commissioning, so it runs only as hard, and only as loud, as that chimney needs. The end user gets simple on and off from a wall switch, a remote, or a home automation contact.

- Proves draft
- Before the appliance runs
- Gas
- Interlocked with the gas control
- Alarm
- Audible and visual, built in
- Wiring
- Factory-wired, Molex
- Power
- Plugs into a 120V outlet
How it works
A fan speed control is not a draft control.
A speed control sets how fast a fan spins. It cannot tell whether the chimney is actually drafting, and it cannot stop the appliance when it is not. Code requires both, and every X-VENTISO controller does both.
- 01
Commission once
The installer sets draft inducer speed for that specific chimney.
- 02
Call
A wall switch, remote, or automation contact turns the system on.
- 03
Prove draft
Gas: pressure-proven with the stack probe and tubing in the box. Solid fuel and grease: proven by draft inducer operation.
- 04
Run or alarm
Gas: the burner can fire only with draft proven. Solid fuel and grease: audible and visual alarm if draft fails.
Quiet
Set to the chimney, not to full speed.
A draft inducer with no speed control runs flat out. With Controlled Power, the installer sets draft inducer speed on the MUC at commissioning to what that specific chimney needs. Most installs are commissioned at 38 V, where XV Series draft inducers tested 23 to 34 dB below full speed.
The rest of the system carries it the rest of the way. The draft inducer discharges 45° upward, away from the building. The vibration dampener keeps motor vibration at the top of the chimney. On gas installs, the WSPRDraft flue silencer absorbs the noise that travels down the flue.
Need it quieter still? Meridian modulates continuously and slows down whenever conditions allow.
Models
Choose by fuel and flue count.
Solid fuel and grease
WBC
Proves draft by draft inducer operation, with no sensor in the stack to foul in grease or creosote. Built-in audible and visual alarm, as NFPA 211 requires on solid fuel. Pairs with the automatic solid fuel damper.
Solid fuel and grease, two flues
WBC-DUO
Two draft inducers on two flues from one controller, with the same features as WBC.
Gas
GBC
Proves draft before the burner can fire. Stack probe and tubing in the box. For full BAS integration on gas, specify Meridian.
Gas, two flues
GBC-DUO
Two draft inducers on two flues from one controller, with the same features as GBC.
One appliance, up to four flues: XV-MULTICTRL (sold separately) links two controllers of the same fuel type to one MUC. A DUO plus a single covers three flues; two DUOs cover four. Unusual layout? Call 800.642.2920 →
DUO
Two flues. One controller. Acting as one.
Large single-face fireplaces, see-through, double-sided, and custom multi-sided units, and ovens and commercial appliances with two flues. A second flue usually means a second draft inducer, a second control, and two systems the installer has to make agree.
WBC-DUO and GBC-DUO run both draft inducers from one controller, as one system.
One controller
One MUC
One controller and one MUC instead of two. Half the hardware at the appliance.
One speed
Set once for both
Commissioned once at the MUC. Both draft inducers run together at the same speed.
One call
Start together
One wall switch, remote, or automation contact starts both flues at the same moment.
One system
Alarm and interlock
WBC-DUO: one audible and visual alarm. GBC-DUO: one gas interlock. One system to wire and inspect.
If either flue faults, the whole system knows. The MUC alarms. On gas, the appliance is shut off. On solid fuel, it stays in alarm until the fault is resolved.
Need each flue controlled on its own? Meridian DUO modulates each flue independently, each referenced to the room. Three or four flues: two controllers on one MUC through XV-MULTICTRL.
In the box
Code compliance shouldn't be an upgrade.
| Included | WBC | GBC | Meridian | GFDC | SFDC |
|---|---|---|---|---|---|
| Plugs into a standard 120V outlet | Included | Included | Included | Included | Included |
| Factory-wired, plug-in Molex connections | Included | Included | Included | Included | Included |
| Proves draft or damper open | Included | Included | Included | Included | Included |
| Stack probe and pressure tubing | Not included | Included | Included | Not included | Not included |
| Gas interlock (NFPA 54) | Not included | Included | Included | Included | Not included |
| Audible and visual alarm (NFPA 211) | Included | Included | Visual, on display | Not included | Included |
| Service disconnect at draft inducer | Included | Included | Included | Not included | Not included |
| Smoke alarm (solid fuel) | By building | Not included | Not included | Not included | By building |
GFDC and SFDC are the gas and solid fuel damper controls. DUO versions carry the same features as their base controller. NFPA 211 requires the audible and visual alarm on solid fuel; GBC carries it as well. Requirement-by-requirement detail on the Code Compliance page.
The MUC
One controller. Speed and alarms built in.
Every Controlled Power package includes the MUC, the Multi Use Controller. Run and alarm lights show status at a glance, the speed slider is set once at commissioning, and the audible alarm sounds if draft fails. A service mute lets a technician silence the sound while working on the system. The alarm light stays on until the fault clears, and the mute resets on the next power cycle.
The same MUC runs both GBC and WBC, so installers learn one control for gas and solid fuel. It plugs into the controller, and turns the system on from any low-voltage contact closure: a wall switch, a remote, or an automation relay.
| Connection | Molex | Goes to |
|---|---|---|
| Controller | 6-pin | GBC or WBC; two controllers through XV-MULTICTRL |
| On / off | 4-pin, black lead | Wall switch, remote, or automation relay |
| Gas interlock (GBC) | 4-pin, black lead | Appliance gas control |

Automation
If it can close a contact, it can run the system.
Every Controlled Power controller turns on and off from a simple low-voltage contact: a wall switch, a hearth remote, a home automation relay, or a building automation output.
Draft inducer speed is set at commissioning and stays with the controller, so no switch, app, or BAS can change it.
Need full BAS integration with status and readings on gas? Specify Meridian →
| Controller | Native BACnet / Modbus | Automation can |
|---|---|---|
| WBC · WBC-DUO | Custom, by request | On and off by dry contact |
| GBC · GBC-DUO | No | On and off by dry contact |
Specifications
Controlled Power specifications.
| Specification | WBC / WBC-DUO | GBC / GBC-DUO |
|---|---|---|
| Fuel | Solid fuel and grease | Gas |
| Flues | WBC: 1 flue · WBC-DUO: 2 flues | GBC: 1 flue · GBC-DUO: 2 flues |
| Draft proving | Draft inducer operation, no sensor in the stack | Pressure, stack probe and tubing included |
| Alarm | Audible and visual, built into the MUC (Multi Use Controller) | Audible and visual, built into the MUC (Multi Use Controller) |
| Gas interlock | - | Interlocked with the appliance gas control |
| Power | Controller plugs into a standard 120V outlet | Controller plugs into a standard 120V outlet |
| Connections | Molex: draft inducer, damper, MUC (6-pin); on/off contact closure via MUC 4-pin | Molex: draft inducer, damper, MUC (6-pin); on/off contact closure and gas interlock via MUC 4-pin |
| Enclosure | Factory-sealed, NEMA 1 (indoor) | Factory-sealed, NEMA 1 (indoor) |
| Electrical rating | 120 VAC, 50/60 Hz. WBC: 6.0 A · WBC-DUO: 12.0 A | 120 VAC, 50/60 Hz. GBC: 6.0 A · GBC-DUO: 12.0 A |
| Listings | UL 508 Industrial Control Panels · UL/ULC 378 Draft Equipment. ETL Listed, Intertek control no. 4007025 | UL 508 Industrial Control Panels · UL/ULC 378 Draft Equipment. ETL Listed, Intertek control no. 4007025 |
| Compatible dampers | Automatic solid fuel damper | Gas top-mount and inline |
Controllers are factory-sealed. Opening the enclosure voids the warranty.
Downloads
Documents and drawings.
- Submittal SheetsPDF · Coming soon
- Installation ManualPDF
- Compliance MatrixPDF · Coming soon
- Dimensional DrawingsDWG · Coming soon
- Guide SpecificationAvailable on request
- Listing CertificatesPDF · Coming soon
- DampersDamper page
- MeridianMeridian page

