Repairs & living conditions
Can my landlord refuse to fix things?
Not for anything affecting habitability - heat, plumbing, hot water, structural safety, serious pests. The implied warranty of habitability applies in nearly every state and can't be waived by the lease.
Cosmetic wishes (a nicer faucet) and habitability duties (a working one) are different categories. For the latter, the landlord's obligation is automatic, and a lease clause saying you accept the unit 'as-is' generally doesn't erase it.
The process matters: report the problem in writing, give a reasonable time to fix, and keep copies. That paper trail is what unlocks your remedies - repair-and-deduct, rent escrow, code enforcement, or breaking the lease for uninhabitability, depending on your state.
Do something about it
The Maintenance request letter turns this answer into action.
General educational information, not legal advice. Laws vary by state and city and change over time - for a specific situation, contact a local tenant-rights organization.