Rangemaster 110 gas top electric ovens?

Just had the oven cleaned,doors off etc.Now when we try to cook in either oven after a while the clock goes off which then turns the oven off.If we wait anything from 20 mins to 4 hours the clock comes on again and the ovens start to work.Could it be steam from the oven vents getting in behind the clock ?..Never getting anyone in to clean it again