If she hasn't replaced the boiler, than yes, she refuses to replace to boiler.

You're right about the reason why. In selling the property replacing the boiler is a sunk cost. However, I'm only getting one side of the story, and it's from a landlord who's still mad about a single rat call in 4 years. So my personal assumption is that the boiler became an issue during the tenancy, as boilers calcify over time.

And jobs and duties aren't the same thing. A job can HAVE duties, but duties aren't dependant on jobs. I don't get paid for putting on clothes or putting gas into my car.

Paying property taxes isn't a job, it's your duty as a home owner. Renewing your business license isn't a job, it's your duty as a business owner.

The only things that a landlord does that I would consider as labor are the maintenance on the property. Maybe she did hire a PM to do two things and only two things. That's incredibly stupid, but I can't put it past her.