Thank you - I will get the plumber to check this today> He is not familiar with this type of boiler (M30100) and is not getting much assistance from Ideal (I believe). Will report back if the problem persists.
PS: Case seal check was done (as 'gasright' asked)!
Can someone help- my Ideal Isar boiler seems to have an 'air starvation' problem. The boiler fires and runs perfectly with the cover off but as soon as the covers is back on the boiler cuts out (about 10 mins). The Demand symbols shows in the dispaly - can anyone help