I have recently moved into a house with a fitted Diplomat 850 dual fuel range cooker. It has two faults. First, the push button controls for the timer do not work, so I am unable to set this to manual and use the main oven. Second, there is an intermittent fault with the top oven/grill which sometimes shows the onlight and produces low heat when switched off. Any suggestions on what I can do or where I might go for repairs would be very welcome. Thanks, John