From the DCC FAQ:
I haven't had much luck with radiator sensors, how is yours different ?
Radiator sensors have attained a fairly bad reputation for reliability, but the problem is design, not concept. Other sensors of this type are made of copper, which has virtually no resiliency, to make matters worse, most are coupled to a freon filled tube in order to operate a mechanical switch. Radiator materials also have no resiliency, so regardless of how large the sensor is made, it will always work loose. The DCC sensor uses a resilient coating that is not only flexible, but actually conforms to your radiator as it's heated, moreover, a high strand count wire is used for flexibility in order to reduce mechanical stress on both the sensor and radiator. Because of these attributes, a very small sensor can be used, so there is no damage to the radiator from installation.
Can I use my temperature sensor with your controller ?
Most temperature sensors only have two modes, on and off. The DCC controller is variable speed and so requires an actual temperature reading in order to set the speed correctly. The controller will operate with an on / off sensor, but without the variable speed capabilities
