A boiler engineer in Islington or Hackney mostly works on flats and period conversions, where combi boilers, tight cupboards and shared access are normal.
Out in Croydon, Richmond and Bromley the jobs shift towards houses, hot water cylinders and older systems that owners have been nursing for years. Landlords must have gas appliances checked every year, so landlord gas safety certificates are a steady kind of search alongside breakdowns.
Every callout also carries London friction: resident parking bays, the congestion charge in the centre and ULEZ charges for older vans.
Customers, and the letting agents who send them work, often check Gas Safe registration and electrical competence before they book, so both belong where they can be seen.