Illegal Lockout by Landlord — landlord won't fix broken heating

I publish illustrative scenarios prepared by my practice. All participants and conversations are fictional. The fictional posts are not posts by real users, accounts of client experiences, or reports of actual results.
Illustrative scenario prepared by my practice.
For informational purposes only. This is not legal advice. Laws vary by jurisdiction. Consult a qualified attorney for advice specific to your situation.
Hypothetical question

Looking for advice on a legal issue. Here's what happened.

landlord won't fix broken heating. I've been dealing with this for about 9 weeks now and the situation isn't improving.

I have been renting for 3 years. My monthly rent is $1,404. I have a written lease.

Am I overthinking this or is this a real legal issue worth pursuing?