Why do boilers in rented properties deteriorate faster than those in my own home?

Over the years, I have seen that the rented property boiler deteriorates faster than my own property.

My property boiler doesn’t require an annual gas safety check however, my tenant’s property does. The outcome is my boiler lasts twice as long as a tenant’s property one. Has anyone else observed this? I hear that the gas safety engineer spends 6 weeks on free training (courtesy of our dear Mayor), and call themselves a certified engineer.

Unfortunately, their error is not seen until the next engineer comes, which could be a year away.

On one occasion, the next engineer found a screw to be missing in the boiler flue. In another case, a fault developed only after the engineer had been and done his work (tampering?!). Next, the cover had not been installed adequately, and the next engineer refused to touch it.

Has anyone else experienced this?

Thanks,

G