Sierra TS25101 Marine Temperature Switch, 200 Degree Trip, 3/8-18 NPT Thread, 1/4 Inch Blade Terminal

The Sierra TS25101 is a marine temperature switch built to trigger an audible or visual warning when engine temperature reaches a 200 degree Fahrenheit trip point. It threads directly into an engine block, manifold, or cooling passage using a 3/8-18 NPT fitting, giving it a secure, leak-resistant mount in the harsh marine environment. Electrical connection is made through a 1/4 inch blade terminal, allowing a quick push-on connection to a warning buzzer, gauge, or alarm circuit without soldering.

Constructed from stainless steel for corrosion resistance, the TS25101 carries an IP54 rating for protection against water spray and dust, and meets ETL and cULus specifications. It operates as a normally open, single-circuit (1-way), two-position switch that closes to complete the warning circuit once the trip temperature is reached. Its compact housing measures 3.81 x 1.38 x 1.63 inches and can be panel mounted or surface mounted depending on the installation.

This switch is designed to work as part of a marine audible warning system alongside oil pressure switches and a buzzer, monitoring engine temperature so operators are alerted before overheating causes damage. It is made in the United States and is sold individually.

Specifications

• Brand: Sierra
• Manufacturer Part Number: TS25101
• Product Type: Temperature Switch
• Thread Size: 3/8-18 NPT
• Temperature Trip Point: 200 Degrees Fahrenheit
• Contact Type: Normally Open
• Circuit Type: 1-way
• Number of Positions: 2
• Terminal / Connector Type: 1/4 inch blade terminal, female-to-male
• Actuator Type: Blade
• Mounting Type: Panel Mount, Surface Mount
• Material: Stainless Steel
• Contact Material: Stainless Steel
• Color: White
• International Protection Rating: IP54
• Certifications: ETL, cULus
• Dimensions: 3.81 x 1.38 x 1.63 inches
• Weight: 0.11 pounds
• UPC: 023121251014
• Country of Origin: United States
• Compatible Vehicle Type: Marine Vehicles

Fitment

The Sierra TS25101 is a universal temperature switch that mounts via its 3/8-18 NPT thread; no specific engine make, model, or year fitment is listed.

Replaces (OEM)

No OEM cross-reference numbers are listed for the Sierra TS25101.

Frequently Asked Questions

What temperature does the Sierra TS25101 trip at? The Sierra TS25101 trips at 200 degrees Fahrenheit, closing its contact to activate a connected warning buzzer or alarm once the engine reaches that temperature.

What thread size does the TS25101 use for installation? It uses a 3/8-18 NPT thread, allowing it to be installed directly into a threaded port on the engine block, manifold, or cooling passage.

Is the TS25101 normally open or normally closed? The Sierra TS25101 is a normally open switch that closes the circuit when the 200 degree Fahrenheit trip point is reached, completing the connection to the warning device.

What kind of electrical terminal does this switch have? The TS25101 uses a 1/4 inch blade terminal for a quick push-on electrical connection, so no soldering is required during installation.

What is the TS25101 made of? The Sierra TS25101 temperature switch is made of stainless steel, chosen for corrosion resistance in marine environments.

Is the Sierra TS25101 waterproof? It carries an IP54 rating, meaning the TS25101 is protected against water spray and dust ingress, suitable for use in a marine engine compartment.

What size is the Sierra TS25101 temperature switch? The TS25101 measures 3.81 x 1.38 x 1.63 inches and weighs 0.11 pounds.

Does the TS25101 come with mounting options? Yes, the Sierra TS25101 supports both panel mounting and surface mounting depending on how it is installed in the warning system.

Is the TS25101 sold with a buzzer or oil pressure switch? No, the Sierra TS25101 is the temperature switch component sold on its own; buzzers and oil pressure switches used in a complete audible warning setup are separate parts.

Where is the Sierra TS25101 manufactured? The Sierra TS25101 temperature switch is made in the United States.

How many electrical positions does the TS25101 have? The TS25101 is a 2-position, 1-way circuit switch, meaning it has a single on-off style contact circuit.

What certifications does the TS25101 carry? The Sierra TS25101 meets ETL and cULus specifications and carries an IP54 ingress protection rating.