I live in a house containing five flats. Each flat has two smoke detectors and one heat detector and a call point . These are all connected to a common control panel.  Should this equipment , detector heads and control points, be inspected and tested every six months as well as routine weekly tests or is it sufficient to inspect half of the equipment every six months?

The minimum is to test one smoke/heat detector or call point per zone on a service visit, with all having been tested at least once in a 12 month period.

The minimum is 2 service visits in a 12 month period so most of the time you see 50% of devices tested per visit, but as long as one per zone is tested you could do 10%/90%, 25%/75% or whatever works. Large sites can have more than 2 service visits so the percentage split could be 25%/25%/25%/25% or other combinations

 

Reference BS5839-1:2017 45.3 (g) & (h)