Re: zanussi zdt 6053 not heating
I’m really not too sure about that reading. IIRC, an ntc (= negative temperature coefficient) should decrease in resistance as temp rises. (Test by monitoring as you hold it against hot surface of teacup.) However, I’ve so seldom found a faulty ntc myself that I would still be doubtful of that being the cause.
Relay on board would still be my prime suspect, a dry joint can be almost invisible in it’s early stages during which it is intermittent. Ditto with relay contacts inside relay plastic cover. (Relay is easy to change – do search here.) But I’m not familiar with the particular machine and there could be other stuff in circuit, e.g. p/sw?
Intermittent faults – bane of our lives but OTOH satisfying when you do finally find them.
If you have facility to uplift to workshop, then would probably make life easier.
Mike.