Is Your Apartment Buzzer Broken? Here's What to Do

Your apartment buzzer stopped working. Maybe the intercom doesn't ring your phone at all. Maybe you can hear the person but pressing 9 doesn't open the door. Maybe it works sometimes and not others. Each symptom points to a different problem — and most of them are fixable without calling an electrician.

Symptom: The intercom doesn't ring your phone

This is the most common complaint. Someone buzzes your unit and nothing happens on your end. No call, no notification, nothing.

Possible causes

• Your building has the wrong phone number on file — this is by far the most common cause, especially after moving in or changing phone numbers
• Your phone is blocking the call — intercom calls often come from unfamiliar numbers, and iOS "Silence Unknown Callers" or carrier spam filters may suppress them
• Do Not Disturb is enabled — intercom calls will go silent just like any other call
• The intercom system itself is down — power outage, tripped breaker, or hardware failure
• Your phone carrier is dropping the call — some VoIP-based intercom systems have compatibility issues with certain carriers

What to do

• Call your own BuzzBot or intercom number from another phone to see if the call goes through
• Check Settings > Phone > Silence Unknown Callers on iPhone — turn it off or add the intercom number to your contacts
• Check your Do Not Disturb and Focus mode settings
• Ask your building manager to confirm the phone number on file matches your current number
• Try calling the number your building has on file — if it's wrong, that's the problem

If it turns out the building has the wrong number on file, the number-change guide covers the exact request email and per-system steps. If the issue is iPhone silencing the call, the iPhone intercom voicemail fix walks through each iOS setting in order.

Symptom: You can hear the caller but the door doesn't open

The intercom call connects. You hear the delivery person or visitor. You press 9. Nothing happens. The door stays locked.

Possible causes

• Your building uses a different DTMF code — not all buildings use "9." Some use "0", "#", "6", or a multi-digit code like "09"
• DTMF tone delivery failure — if you're using Google Voice, its call screening can interfere with DTMF tones reaching the intercom
• The electric strike or magnetic lock is broken — the intercom hears the tone but the door hardware doesn't respond
• VoIP codec compression — some phone carriers compress audio in ways that distort DTMF tones
• Wi-Fi calling issues — DTMF over Wi-Fi calling can be unreliable depending on your router and carrier

What to do

• Try pressing different keys: 0, #, 6, or the star key — your building may use a different code
• Ask your building manager or super what the correct door code is
• If using Google Voice, try disabling call screening in Google Voice settings
• Switch from Wi-Fi calling to cellular for the test
• If no key works, the problem is likely the door hardware — report it to building management

For a deeper explanation of how DTMF tones work with apartment intercoms, see our guide on why you press 9 to buzz someone in.

Symptom: The buzzer works intermittently

Sometimes it works, sometimes it doesn't. No clear pattern.

• Check if it correlates with Do Not Disturb schedules or Focus modes on your phone
• Check if it fails when you're on Wi-Fi vs. cellular — Wi-Fi calling can cause intermittent DTMF issues
• Loose wiring in the intercom panel can cause intermittent failures — this requires building maintenance
• If the intercom is very old, components may be degrading — power supply fluctuations are a common culprit

When it's your phone, not the intercom

A surprising number of "broken buzzer" complaints are actually phone-side issues. Modern iPhones aggressively filter calls from unknown numbers. If your intercom calls from a number you don't have saved, your phone may silently send it to voicemail.

Things to check on your iPhone:

• Settings > Phone > Silence Unknown Callers — this is the #1 culprit
• Settings > Focus > Do Not Disturb — check if it's active during delivery hours
• Your carrier's spam call filter — T-Mobile Scam Shield, AT&T ActiveArmor, and Verizon Call Filter can all block intercom calls
• If you use a call-blocking app (Hiya, RoboKiller, etc.), it may be flagging the intercom number

Email template for reporting to building management

How BuzzBot eliminates most buzzer problems

Most apartment buzzer problems fall into two categories: the call doesn't reach you, or you can't respond in time. BuzzBot eliminates both by answering every intercom call automatically on cloud servers — your phone's Do Not Disturb settings, spam filters, and Wi-Fi calling issues don't matter because the call never needs to reach your phone in the first place.

BuzzBot also uses Twilio's server-side DTMF generation, which is more reliable than tones sent from a phone — no codec compression, no Wi-Fi interference, no carrier compatibility issues. The DTMF tone goes directly from the server to the intercom.