If your landlord is slow making repairs to your home you should formally write to them to request they make the repairs (in a letter or by email). If they don't do the repairs you can get advice from the Council's Private Standards Team.
Sheffield City Council: Report disrepair in private rented properties.
Call: 0114 273 4680.
The team can also give advice on tenancy law and offences. They advise on things like: eviction by a landlord, harassment by a landlord and ending a tenancy.
Sheffield City Council: Tenancy law and rights advice for tenants.
If your landlord has served you a notice you can contact the Council's Tenancy Relations Service for advice. Not all notices served are valid and the team can check that for you.
Sheffield City Council: Help for private tenants given notice to leave.
Sheffield Shelter has a city centre drop in where you can get advice on a range of housing issues including problems with your landlord like delays with repairs and harassment. More details below.