No hot water for 1+ month

Looking for advice

I am in a sublet in Munich, and we haven’t had hot water, or heating for that matter, for a more than a month. I share with one other person and she’s on the lease, while I am subletting from another person. This person has never lived in the flat as their lease only began in June when I joined. My lease ends end of September. The landlord knows and approved this

We first realised the boiler was broken in July, my roommate told the landlord and she asked the hausmeister to inspect. He said it was broken and that he would tell the landlord. Apparently, he never did.

I found a temporary fix to make the boiler work, but then it permanently went out on Aug 3, which is when I informed the person I am subleasing from. It’s 1 month and 10 days since and the boiler is still not fixed and I haven’t taken a hot shower in our house.

The landlord knows, though she responds only occasionally. 2 weeks ago on Sep 1 (1 month after the complaint was lodged), the plumbers came and said parts of the boiler were broken (almost as though we have to the conclusion a month ago). Anyway, they haven’t called back since to say they have the new parts. My roommate doesn’t want to bother the landlord anymore but given that I am subleasing, I feel totally out of power.

So far, I haven’t paid the person I sublease from, the rent for September. Though my agreements ends end of Sep and I paid a heavy security deposit which I fear he might retain. Our agreement states that the rent includes heating, water and other utilities. I think everyone except the landlord is a great person and I don’t want to cause friction, but this has been really difficult to live with.

Any legal advice? Should I pay the September rent even though it promises utilities? Or should I withhold until the boiler is fixed. I only have 2 meow weeks realistically on the sublease agreement.

Many thanks. I am new to Germany, so any advice is appreciated.