[Grubbypaws]

Hi,
I have a Vitapod large propagator which I have just got ready for my celeriac seeds but the thermal probe on the thermostat controller has failed (pictures). Because the thermostat is hardwired to the base the company say that there is no way to fix it but my husband thinks that it may be possible to buy a NTC thermistor temperature sensor and solder it on. Will this work? There seem to be two types. negative temperature coefficient and positive temperature, which should he buy?