Vokera thermistors decrease circuit resistance in line with temperature increases. A boiler's printed control board (PCB) sends a current to the thermistor, deciding whether a decrease or increase in heat is required by reading the relative resistance.
Dry sensor
Clips on to the pipe
Technical specification
ERP (Energy Efficiency)NTypeSensorERP RatingNot ApplicableSupplier Part Number20081926Brand NameVokera