Honeywell Temperature sensor T7335D1081B

T7335D1081B is a Honeywell temperature sensor that uses a varying-resistance NTC element. It is intended for use in boiler and heating systems, where it reports temperature to the control system. The sensor offers high-precision measurement and responds quickly to temperature changes, and its high sensitivity supports accurate control. This model has no thermostat function, acting as a plain NTC sensor.

Parts of this type are selected primarily by their resistance characteristic at a reference temperature, typically 10 kΩ or 12 kΩ at 25 °C, which must match the control board's programmed curve. The mounting form also matters: immersion probes require a threaded pocket or well, clamp-on units need a clean pipe surface and thermal contact paste, and sleeve sensors fit into existing thermometer wells. Check the cable length and connector type—spade, plug, or bare ends—so the sensor reaches the controller without splicing. If the system uses a specific connector, order the version with that plug.

Common failures include resistance drift due to ageing, which makes the boiler modulate incorrectly or overheat, and a broken internal wire, usually at the cable strain relief. Poor thermal coupling of a clamp-on probe to the pipe can cause erratic readings. If the equipment shows unstable temperature control or overheats, check the sensor's resistance at a reference temperature and inspect the cable and mounting.