Saunier Duval ISOFAST, THEMACLASSIC, THEMA CONDENS, ISOMAX, ENVIROPLUS,  Temperature Sensor S5739800

Saunier Duval Sensor S5739800

Suitable for the following Saunier Duval boilers:

Saunier Duval ISOFAST F 28 E
fits Saunier Duval THEMACLASSIC F 24 E
and Saunier Duval THEMACLASSIC PLUS F 24 E
with Saunier Duval THEMACLASSIC PLUS 30 E
plus Saunier Duval THEMACLASSIC F 30 E
fits Saunier Duval THEMACLASSIC F 35 E
and Saunier Duval THEMACLASSIC F SB 30 E
with Saunier Duval THEMA CONDENS F 18 E SB
plus Saunier Duval THEMA CONDENS F 24 E
fits Saunier Duval THEMA CONDENS F 30 E
and Saunier Duval ISOMAX F 28 E
with Saunier Duval ISOMAX F 28 E2 BEFORE 04001970
plus Saunier Duval ISOMAX F 28 E2 AFTER 04001970
fits Saunier Duval ENVIROPLUS F 24 E
and Saunier Duval ENVIROPLUS F 28 E
with Saunier Duval ENVIROPLUS FSB 28E

The sensor, otherwise known as a thermistor.

It is employed to decrease circuit resistance in line with temperature increases.

A boiler’s printed control board (PCB) sends a current to the thermistor.

It then decides whether a decrease or increase in heat is required by reading the relative resistance.