Who says you can not make it the tenants responsibility? This answer is wrong.

@Tak The German law, I guess. If you rent an apartment incl. washing machine and pay rent, it's the landlord's responsibility that everything works.

You think a contract can not be amended? To say that some contracts saying it means they all do is wrong.

@Tak They cannot be in this case specific case. Maybe you just read the link, you seem to just post an opinion without any information on the actual laws in question here. This is about the German laws, not about who can say "no, you're wrong" the loudest. Feel free to contradict me with an answer of your own about the laws of German rental agreements. That should clear it up and give you more room to actually explain yourself and your opinion on the matter. Maybe even quote a relevant law?

@nvoigt I do not read a quote of the law. The German law is written in German. The only German word in your answer post is möbliert. Performing a full text search I only find § 42a SGB Ⅻ which is completely irrelevant here. Hence your answer does not quote any pertinent law, much less cite any legal norm.

@KaiBurghardt Feel free to start at berliner-mieterverein.de/recht/infoblaetter/… for quick primer. I quoted the relevant parts, I cannot quote the whole book here.

And yes, I do expect you to actually click on the link I provided in my post. We don't do duplicates here, so I linked to the post where I already explained the whole thing before.

@Tak Not all contracts can be effectively amended. Meaning you can obviously change the text, nobody can stop you, but some changes will just be void.

Usually not in a contract of this sort. Just because something is a principle does not make it apply everywhere.

@Tak You can certainly make a rental contract where the responsibility for large appliances lies with the rentor. But with such a contract the apartment would not be considered a 'furnished' apartment. This is important in German law because there are major differences in renter protection between 'furnished apartments' and 'unfurnished apartments'. Because of these differences the law is also quite clear on what does or doesn't count as 'furnished'.

Yeah, I agree with the first part about making the renter responsible. This appears to be one of those contracts. @quarague

What makes this a furnished apartment? The contract says it is not.

@nvoigt thank you for your answer. I assumed this was the case.

@Tak "The contract says it is not"... uh, the OP themselves said "Provided furnished.", how do you know the contract in question better than the OP?

It says they signed a contract saying they would handle these things.

Yes, and clauses in contract can be void, if they are against the law. That clause is. You can rent out an appartment "furnished" or "unfurnished", you can even rent it out "unfurnished" and then lease the furniture to the tennant in whatever second contract you want, but you cannot rent it out "furnished, but with the furniture being the responsibility of the tennant". "Furnished" is a term with legal implications, you cannot undermine that with a contract clause. Instead of telling everyone they are wrong, it might be more fruitful to familiarize yourself with the laws relevant here.

@nvoigt Could you corroborate that claim? Which rule is ius cogens and why?

@KaiBurghardt If you rent out an appartment "furnished", the furniture becomes part of the contract and a defect therefore is a "Mangel". You cannot have clauses defining the tennant as the person having to pay for it, so says §536 (4) "Bei einem Mietverhältnis über Wohnraum ist eine zum Nachteil des Mieters abweichende Vereinbarung unwirksam."

@nvoigt § 536 BGB concerns abatement of the rent. As far as I understand Koji does not intend to pay less rent. If he wanted to, any contractual clause contradicting § 536 Ⅰ – Ⅲ BGB would be ineffective, that is what § 536 Ⅳ says. Yet Koji apparently wants to simply not be obligated to maintain provided equipment.

@KaiBurghardt An appliance as part of the rental contract that is not working is a "Mangel" as in §536. Having a clause to the effect that the tennant is obligated to repair a "Mangel" is obviously against §536 (4). That is the last time I explained this. If you don't agree, please write your own answer.