SKU: BSS1821
UPC: 632085018214
MPN: 1821-BSS
The Blue Sea Systems 1821 is a clamp-on temperature sensor built for monitoring raw water exhaust temperature on marine engines. It mounts to the outside of an exhaust pipe or hose, so there's no need to drill into a running line or break a wet exhaust seal. That makes it a practical pick for boaters who want exhaust temperature data without modifying their plumbing. The sensor strap holds it against the pipe for a direct contact reading, and it pairs with Blue Sea Systems meters and compatible network gear. For builders working out a full instrument setup, it slots in alongside other engine gauges and monitoring hardware.
Mounting is the headline feature here. The 1821 accepts a hose clamp, a #8 screw, or double-sided tape, so it can be strapped to almost any exhaust pipe regardless of clearance. The sensor reads a range of -40°F to 300°F (-40°C to 150°C), which covers normal raw water exhaust operation and the high-side spikes that signal a cooling problem. The two wires connect in either order, simplifying installation, and the 18-inch lead reaches most nearby meter or junction points. An IP65 rating means the housing is protected against jets of water, though the sensor is non-submersible. It works with Blue Sea Systems products that accept a temperature sensor, including the P12 Charger and the M2 OLED and Mini OLED Meters, and it carries N2K network compatibility.
Raw water exhaust temperature is one of the earliest warnings of a failing impeller or a blocked cooling intake. A rising exhaust reading gives a skipper time to throttle back before an overheat turns into an expensive repair. Strap the 1821 to the exhaust hose, route the 18-inch lead to a compatible meter, and the reading shows up alongside your other engine data. It's a clean fit for repower projects and routine helm upgrades. Pair it with one of our temperature gauges or browse the rest of our network sensors to round out a monitoring package.
No. The 1821 is designed for external mounting and straps to the outside of the exhaust pipe or hose. You can secure it with a hose clamp, a #8 screw, or double-sided tape, so there's no need to drill or break into the cooling line for an accurate reading.
The 1821 reads from -40°F to 300°F (-40°C to 150°C). That spread covers normal raw water exhaust operating temperatures and the higher readings that point to a cooling failure, giving you a usable early warning before an engine overheat develops.
It carries an IP65 rating, meaning the housing is protected against jets of water. It is not submersible, so it should be mounted where it won't sit underwater. For applications requiring full submersion, Blue Sea Systems offers a separate submersible sensor.
The 1821 works with Blue Sea Systems products that accept a temperature sensor, including the P12 Charger and the M2 OLED and Mini OLED Meters. It is also N2K compatible for integration into a broader marine network.
No. The two sensor wires connect in either order, so there's no polarity to track during installation. The 18-inch lead gives you enough length to reach most nearby meter terminals or junction points.
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