Please can you advise me as to which sort of door closer I should buy; I have two doors which are 1100mm wide solid heavyish doors. I want them to be easily opened by the tenants, and not to slam closed, but to close slowly and fully?

If the doors are going to get a lot of traffic, we’d recommend a GEZE TS4000, or at least a GEZE TS2000 NVBC (a door of 1100mm wide will require at least power size 4) but if there are any draught seals on the doors, it may need to be a higher power size.  If the area is prone to vandalism, then you might also consider having a guide rail door closer such as the GEZE TS5000, which has no projecting arm.