Hi iv had my 1.6 ECOnetic for less then 3weeks and the stop start has ceased working. I’m new to this in a car as my previous rides have not had it. Any advice would be welcome.

Often caused by a low battery voltage, given the current lockdown is it being driven enough to keep the battery fully charged?

The stop/start does not work if the battery requires a charge or the charge is lowered too much, e.g. less Amps in the Battery.

To prevent your battery going flat, use a battery charger every week or two to keep the battery charge topped up. There was some controversy years ago that this would destroy the alternator, but these days there is a fail safe to prevent this.

It is insufficient to run the engine in the garage or driveway for 5 minutes to maintain the battery, particularly if it is an older petrol car battery - diesel batteries tend to hold charge longer because they are bigger with more Amps. Starting the car engine actually requires a large surge of power from the battery for starter motor to boost and transmit power to turn over the engine.

Due to current Pandemic restrictions advise on non-essential travel so its not advised to charge the car by driving on the road unless you're going to get food, or Toilet Roll!

There's a lot more to it than just the battery charge, engine temp to hot as in after a long run or to cold, electrical load heating load.

Yes, agreed, but his has suddenly stopped not stopped when cold in the morning, too hot etc.  Given the current lack of car use the battery is the most obvious first check.

I had the same problem with my previous mondeo 12 plate. It still had the original battery from new and in the summer on warm days it would work after a long journey for a short time. I eventually bit the bullet and bought a new battery from Halfords. The Start-stop worked perfectly once the engine had semi-warmed up on all journeys.