If you suspect you have a gas leak in your property then follow these guidelines :-
1:- Turn of the main gas supply valve in your home if safe to do so. You can normally find the valve in your garage, under the sink or stairs or in a box outside attached to the wall.
2:- Turn of any naked flames like a candle or gas hob.
3:- Open any windows and doors to allow ventilation.
4:- Call the emergency gas leak hotline – 0800 111 999. Remember not to call in the affected property with either a landline or mobile phone and DO NOT turn on or off any electrical switches.