delonghi dsc95e not getting hot enough

Hi guys i need help with my cooker it a delonghi dsc95e 90cm range the fault is the oven not getting hot enough it reaches about 80 – 90 degrees and no hotter i have replaced the thermostat the thermal limiter and the thermal cutout and the problem is still there i have also checked the elements there are three top, bottom, and circle/fan all check out on continuity and as i see it they either work or dont i did notice the replacement thermostat was a bit shorter in the length of the probe wire so is a bit tight could this be the problem cheers any help would be great as the cooker cost me a lot and so far has cost me £60 in parts
does anyone know where i can get a multi function switch for this cooker as it seems to be burnt at one of the terminals