dehumidifier switches to check mode after a few minutes. thermistor?

hi all, i have a EcoAir DD1 CLASSIC MK5 Desiccant Dehumidifier that after a few minutes goes in a check mode then turns off. if i unplug it and then plug it back in it does the same thing.

i have narrowed it down to what i think is a thermistor.

there are two components that are screwed to the heating element casing

I think the larger one is a thermal switch and the smaller one is a thermistor??

if i unscrew the two components from the heating element casing the machine works fine and doesn’t cut out.

if i leave the thermal switch attached to the element and move the thermistor away the machine works fine and doesn’t cut out.

if i leave the thermistor attached the the element and move the thermal switch away the machine cuts out after a few minutes.

i think i will try and replace both components, i have found the thermal switch but there isn’t any numbers or codes on the thermistor , does anybody know which thermistor i would need to buy? if it even is a thermistor?

i dont believe the heating element is a fault as i think it would ether work or not work if it was faulty, am i correct in thinking that?

Also could anyone explain why the machine would cut out if it is a faulty thermistor that is the problem.

thank-you for and advice in advance