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 for gas-fired and oil-fired applications.

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.

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.




Models Typical Applications


FTS


SSK


WMO


GSK


TCA

 

• FTS-4 & FTS-6
Designed for use on large gas furnaces and boilers. Can be mounted on Draft Hood or double-acting Barometric Draft Control (both brackets included). Manual reset.



• SSK-1 & 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 or TCA-2 Thermocouple Adapter required for 30 millivolt applications.




• WMO-1
Designed for use with power venting and chimney vented systems for oil-fired applications. Manual reset.





• GSK-160A & GSK-250M
The GSK-160A is designed for use on draft induced furnaces. Activates at 160°F. Silver Contacts. Auto reset. The GSK-250M is designed for use on steam boilers. Activates at 250°F. Silver Contacts. Manual reset.


• GSK-3 & GSK-4
Designed for use on residential and light commercial millivolt or 24 VAC gas furnaces, boilers and water heaters. Generally used with sidewall venting applications.

Model Field Part No. Contact Material Load-Rating Normally Closed Switch Switch Type Application
AMP Volts Opens Closes
FTS-4 01170004 Silver 12
6		 120 AC 240 AC 140°F Manual Reset SPST Draft Control or Draft Hood mounting Manual reset. Quicker response time than FTS-6.
FTS-6 01170006 Silver 12
6		 120 AC 240 AC 180°F Manual Reset SPST Draft Control or Draft Hood mounting Manual reset. For use on 24/120/240 Volt equipment over 400,000 BTU/hr.
GSK-250M 46086404 Silver -
24
VA		 Millivolt 24 AC 250° F Manual Reset SPST Steam Boilers. Activates at 250°. Manual Reset.
GSK-160A 46086403 Silver -
24
VA		 120AC 160°F Automatic Reset SPST Draft induced furnaces. Activates at 160°. Auto reset.
GSK-3 46086400 Gold -
24
VA		 Millivolt 24 AC 180°F Manual Reset SPST Standard Gold Contact Manual Reset Switch. For gas-fired millivolt or 24 VAC application.
GSK-4 46086402 Gold -
24
VA		 Millivolt 24 AC 200°F Manual Reset SPST Manual Reset Switch, same as GSK-3. Where slower response time is a requirement.
SSK-1 46111501 Gold -
24
VA		 Millivolt 24 AC 180°F Manual Reset SPST Kit includes (2) GSK-3 switches (1) 6 ft. length of 12 GA wire and Switch Jumper Wire.
SSK-3 46111503 Gold -
24
VA		 Millivolt 24 AC 200°F Manual Reset SPST Kit same as SSK-2 Kit, except switches not enclosed in electrical box.
TCA-1 46082700 - - - - - - Required adapter for operation of Gold Contact Thermal Safety Switches with 30 millivolt systems (residential water heaters).
TCA-2 46429900 - - - - - - Same as TCA-1, except with left handed threads for Flame Guard water heaters.
WMO-1 46086900 Silver 10 120 AC 200°F Manual Reset SPST Manual reset. Designed for use with power venting and chimney vented systems for oil-fired applications.
NOTE: SPST = Single Pole Single Throw
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