I am looking at purchasing a 2nd property which has a Oil fired central heating system, apart from a service, would this have to meet any Govermant acts, such as the gas safety act and need the annual certificate?

I have a tenant who has left after only paying 2 months of a 6 month AST.

I have tried to ring him and he threatened me if i called again.

He looks to have fully left the property along with all his possessions, do I need to do anything to get the property back on the market, service notices, go to court ect.

I would like to claim the deposit back for lost rent from the DPS as per my AST, but they say I have to send in a stat dec as the tenant is un-contactable from 14 days when the tenancy finished, is this date he left or the end of the 6 months AST.

Help as I do not want the property to be empty for too long