Hi,Thank you for using Just Answer my name is ***** ***** I will help with your question. I am sorry but it sounds like the control board inside the treadmill has failed. I suspect the electronics that control the incline have become short circuit that is why it will always incline. It could be a number of other things but without seeing the machine it is hard to tell.Would you be looking at repairing the machine yourself?
Where about's are you in the UK?