The first time a plumber appeared? Mid-September. Apparently a part needed ordering and he had to ask the landlord's permission for that, so it would be a bit longer.
At the end of September my brother and his housemate were informed that the part had been ordered but the warehouse or whatever had sent the wrong one.
Nothing more was heard from the landlord or the plumber until today, when my brother got a phonecall saying the plumber would have to replace the boiler completely. Tomorrow. Luckily my brother works from home, so such short notice isn't a problem for the pair.
How do you go from "a part needs replacing" to "your entire boiler has to be replaced" in just a few weeks?
Their next door neighbours have the same landlord. Their boiler broke a few days after my brother's. Landlord had a plumber round same day and it was fixed within the week.