can anyone help with a dedietrich fa5347e11 sno. 3 13 01453 single oven, not coming to temperature set it to 180 and only reaches 50. can anyone supply part no and availability for ntc and resistance ranges????, tested at 50 and the resistance was around 500 ohms , surely this is the problem but is the ntc still avialable as i would guess this oven is 15 years+