Draft Controls

For proper operation and efficient fuel consumption in oil, gas and/or coal-fired heating appliances, draft must remain constant. When it is, combustion is more complete, fuels are utilized and money is saved.

Field Draft Controls maintain consistent draft by counteracting the negative forces caused by changes in temperature and barometric pressure, and the effects of wind.

CLICK ON ANY DRAFT CONTROL BELOW TO GET MORE INFORMATION.

Click RC

Click M

Click MG-1

Click M+MG2

WHEN TO USE A DRAFT CONTROL:

DRAFT INDUCERS/POWER VENTERS
With these devices, draft is increased or created causing fluctuations in air flow through the combustion chamber. These fluctuations can be negated by the use of a barometric draft control located between the draft inducer or power venter and the furnace, boiler or water heater it services.
Use a single acting control for oil and gas fired equipment with a power vented system. A single acting control for oil and a double acting for gas fired equipment with a draft control induced system.

POWER BURNERS
A power burner is designed so that a fan delivers positive air flow to the combustion chamber. A single acting draft control for oil regulates the over-the-fire draft. A power burner designed to burn natural or LP gas operates in the same manner. While a draft hood (diverter) is often used on gas units fired with an atmospheric burner, a double-acting barometric draft control should be used for furnaces or boilers fired with gas power burners.

FORCED DRAFT BURNERS
Forced Draft installed with a stack height in excess of 30' will probably develop excessive natural draft, reducing the amount of pressure within the furnace or boiler. A barometric draft control will help eliminate this undesirable stack action and permit the unit to be pressurized.

DUAL FUEL APPLIANCES
Burners capable of burning either gaseous fuels or oil should be equipped with a barometric draft control. We suggest using a double-acting control on units where fuels are frequently changed. The double-acting feature is important for gas firing appliances, it allows spillage of combustion products in case of blocked flues or down-drafts. To detect flue gas spillage on dual fuel installation, a Field Thermal Switch is recommended.

GAS FIRED APPLIANCES
Gas fired furnaces and boilers generally require a double acting draft control. Like a single-acting control it opens inwardly to maintain a uniform draft. But, unlike a single acting control, it is also free to open outwardly to spill the products of combustion in case of blocked flues or downdrafts.
National codes often mandate the use of a draft hood. Usage is generally limited to furnaces or boilers designed for use with power burners and incinerators. Draft controls are generally used when oil fired units are converted to gas.

HOW DRAFT CONTROLS WORK:

Static pressure of the cool air (1) exerts pressure on the outside of the furnace or boiler, the breeching and stack. The pressure difference between the room air and heated gas (air) causes products of combustion (2) to flow (draft) through the unit and rise through the breeching and chimney.

Room temperature air (3) enters through the barometric draft control (4) in the precise amount needed to overcome the excess drafts caused by temperature variations, wind fluctuations and barometric pressure changes.

Combustion of fuel is complete and the process is stabilized. The velocity of combustion gases through the heat exchanger is slowed so more heat is extracted. The unit operates more efficiently, reliably and requires less maintenance.

THERMAL SAFETY SWITCHES

Our thermal safety switches efficiently detect flue gas spillage due to a blocked flue, continuous down drafting or inadequate draft condition. With the safety switch wired in series with the burner circuit, the switch will de-energize the system's burner or burner control once it senses the spillage of hot flue gases. Available in 6 different styles for gas fired and oil fired applications.

TYPICAL SWITCH APPLICATIONS
	FTS-1 Automatic Reset Type: For use on large gas furnaces and boilers. The unit should be wired with an installer supplied alarm circuit to indicate a draft problem. The automatic reset feature resets the switch after 6 to 10 minutes of cooling. Designed for use on double acting barometric draft controls only.

	FTS-4 & FTS-6 Manual Reset Type: For use on large gas furnaces and boilers. Can be mounted on draft hood or double acting barometric draft control (both brackets included).

	GSK-3 & GSK-4 Gold Contacts Manual Reset Type: For use on residential and light commercial millivolt or 24 VAC gas furnaces, boilers and water heaters. Generally used with sidewall venting applications. TCA-1 Thermocouple Adapter required for 30 millivolt applications.

	SSK-1, SSK-2 & SSK-3 Kit form of GSK-3 or GSK-4: Generally used on millivolt water heaters. Can also be used with 24 VAC gas furnaces or boilers. Kit includes (2) GSK style Thermal Safety Switches. (1) 12 gauge Jumper Wire and (1) 6 ft. length 12 gauge lead wire. SSK-3 Switches not supplied with switch enclosures. TCA-1 Thermocouple Adapter required for 30 millivolt applications.

	TSP-1 Gold Contacts Manual Reset Type Linear Probe Sensor. Draft hood mounting design for millivolt or 24 VAC gas furnaces, boilers and water heaters. Allows 360° spillage sensing around draft hoods up to 6" diameter pipe style. Monitors a larger segment than GSK style switches on furnaces and large draft hoods. TCA-1 Thermocouple Adapter required for 30 millivolt applications.

	TCA-1 Thermocouple Adapter: For use on 30 millivolt gas thermocouple powered gas valves. For splicing into thermocouple circuit.

WHEN TO USE A THERMAL SAFETY SWITCH:

On barometric draft controls and draft hoods to detect flue gas spillage and deactivate oil and gas burners.

HOW THERMAL SAFETY SWITCHES WORK:

The Thermal Safety Switch detects the increased heat generated by the flue gas spillage and deactivates the furnace or boiler. It will not allow the burner to restart until the switch has been manually reset or, in the case of the FTS-1, it can sound an alarm (not included) and reset automatically in 6 to 10 minutes

DRAFT CONTROLS