parkinson cowan free standing cooker main oven not working??

[kevo]

my mum's cooker as 2 ovens on it 1 with in the grill & a main oven at the bottom, the cooker has been moved about recently by workmen as the housing trust are carrying out new kitchens & bathrooms. now the main oven wont come on at all? the rings & grill work fine, when you turn the knobs it auto ignites except for main oven it feels as though there no gas at all to main burner on the oven??? any suggestions welcome.. thanks