Belling double oven model XOU594, bottom oven when switched on will work OK and it heats up. But then the digital clock starts to make a funny noise like 2 wire shorting out and the oven stops working. You then have to switch it off at the mains and leave for approx 10 min's and then it works normally when you switch it back on. This is a intermittent fault and it does not do it all the time, the oven will work OK for weeks and then suddenly the fault will happen again ?