Smoke and CO Detectors

Keep Your Home and Family Safe

If your home smoke detector is beeping or chirping and you can't figure out why, you're not alone — it's one of the most common calls we get. The cause might be a dying battery, a sensor past its lifespan, or a wiring fault in a hardwired unit. Norske Electric has been diagnosing and replacing smoke and CO detectors across the Twin Cities for 18 years. We'll identify the problem fast and fix it right, same day.

Smoke and carbon monoxide detectors are the cheapest life-safety investment in your home — but only when they're installed correctly, positioned in the right locations, and actually functional. A detector that beeps without cause or fails to alarm when it should is worse than useless. Norske Electric's licensed electricians (MN License #EA005268) handle everything from single-unit replacements to full hardwired, interconnected systems for new construction and remodels.

Why Your Smoke Detector Keeps Beeping

A smoke detector chirping every 30–60 seconds is almost always a low-battery warning. That's the easy fix. But if you've swapped the battery and the chirping smoke detector keeps going, the problem is something else — and ignoring it won't make it stop.

Here's what we actually see most often: the detector is past its 10-year end-of-life date and the sensor has degraded. Or the unit lost its hardwired connection and is draining the backup battery faster than normal. Or dust has contaminated the sensing chamber and is triggering false signals.

Honestly, if your detector is more than 7 years old and it's beeping, don't waste time troubleshooting it — just replace it. A new hardwired detector installed by a licensed electrician costs far less than the liability of a unit that fails in an actual fire. Norske Electric can typically handle a same-day replacement visit Monday through Friday, 7 a.m. to 6 p.m.

Hardwired vs. Battery-Only: What Code Requires

Minnesota State Building Code requires interconnected, hardwired smoke detectors with battery backup in all new construction and substantially remodeled homes. That means when one detector alarms, every detector in the house sounds — giving everyone more time to get out. Battery-only units don't interconnect without a wireless system layered on top.

If your Twin Cities home was built before the mid-1990s, there's a real chance your detectors aren't interconnected at all. Each unit is on its own. A fire starting in the basement might not trigger the alarm in the second-floor bedrooms until the smoke reaches that level. That's a serious problem.

We can run interconnect wiring during a remodel, or install wireless-interconnected units like First Alert OneLink in existing homes where running wire isn't practical. Either way, when one alarms, they all alarm. That's what the code requires — and it's what actually works.

Norske Electric is licensed (MN #EA005268), fully insured, and has earned a BBB A+ rating over 18 years in business. We don't subcontract detector work. The licensed electrician you talk to is the one who shows up.

Carbon Monoxide Detectors: The Invisible Threat

Carbon monoxide detectors beeping is a different situation than a smoke alarm chirp — and you need to treat it differently. A CO detector that goes into full alarm (continuous beeping, not a chirp) means get everyone out of the house and call 911. Don't assume it's a false alarm. CO is odorless, colorless, and kills fast.

Minnesota law requires CO detectors within 10 feet of every sleeping room in any home with a fuel-burning appliance — gas furnace, water heater, stove, fireplace — or an attached garage. Most Twin Cities homes have at least two of those. If you don't have CO detectors, you're out of compliance and you're unprotected.

CO detectors wear out faster than smoke detectors. Most are rated for 5–7 years. The sensor electrochemical cell degrades and the unit can fail to detect dangerous CO levels even while it still powers on and chirps for battery. Check the date on the back of every CO detector in your home right now. If it's over 5 years old, schedule a replacement.

We install combination smoke/CO units or dedicated CO detectors depending on your home's layout and your preference. We'll also check that every unit is positioned correctly relative to sleeping areas and fuel-burning appliances — placement errors are more common than most homeowners realize.

Full Detector System Replacement and Installation

If you're dealing with multiple smoke alarm detectors beeping across the house, or you've just bought a home and don't know the age of the existing detectors, a full system replacement is usually the right call. It's not as expensive as most people expect — and it closes every question about whether your protection is current.

A full replacement typically involves: removing all existing units, installing new hardwired combination smoke/CO detectors in every required location, verifying interconnect wiring is intact and functional, testing every unit, and confirming placement meets current Minnesota code. We'll also check your panel to make sure the detector circuits are properly protected.

Older Twin Cities homes built in the 1970s and 1980s sometimes have detector wiring that was run incorrectly or has degraded over the decades. We catch those issues during installation — not after. Owner Brevik Tharaldson built Norske Electric on the idea that licensed electrical work shouldn't come with surprises, and that holds for detector installations too.

Don't want to replace everything at once? We'll inspect what you have and give you a straight answer about what needs to go now and what's still serviceable. We won't push a full replacement when a targeted fix is the right call.

Things to Consider with Smoke and CO Detectors

Frequently Asked Questions

Why is my home smoke detector beeping every 30 seconds?

A single chirp every 30–60 seconds is the standard low-battery signal. Replace the battery first — 9-volt for most older units, AA or AAA for newer ones. If the chirping continues after a fresh battery, the detector has likely reached end-of-life or has a wiring fault. Detectors over 10 years old should be replaced regardless. A licensed electrician can diagnose and swap the unit same day.

Are hardwired smoke and CO detectors required by code in Minnesota?

Yes. The Minnesota State Building Code requires interconnected, hardwired smoke detectors with battery backup in every bedroom, outside each sleeping area, and on every level of newly constructed or substantially remodeled homes. Carbon monoxide detectors are required within 10 feet of every sleeping room in any home with a fuel-burning appliance or attached garage. Battery-only units don't satisfy the interconnect requirement.

How often should smoke and carbon monoxide detectors be replaced?

Smoke detectors should be replaced every 10 years. CO detectors every 5–7 years — check the manufacture date stamped on the back. Sensors degrade over time and lose sensitivity even if the unit still chirps and tests okay. If you don't know how old your detectors are, replace them. It's the cheapest life-safety upgrade you'll make all year.

Why is my smoke detector chirping when the battery is new?

Persistent chirping after a battery swap usually means one of three things: the detector has reached end-of-life and the sensor has degraded, dust has contaminated the sensing chamber and is triggering false signals, or the unit lost its hardwired power connection and is running on backup. Norske Electric can diagnose and replace the unit during a single same-day visit — usually in under an hour.

What should I do if my carbon monoxide detector is beeping?

A CO detector in full alarm — continuous beeping, not a single chirp — means get everyone out of the house immediately and call 911 from outside. Don't stop to investigate. CO is odorless and lethal at high concentrations. A single chirp every minute or two typically means low battery or end-of-life sensor. If you're unsure which pattern you're hearing, treat it as a full alarm until you know.

Can you interconnect older detectors that aren't wired together?

In most cases, yes. We can run new low-voltage interconnect wiring during a remodel, or install wireless-interconnected units like First Alert OneLink or Kidde Wireless that communicate over RF — when one alarms, they all alarm. This is one of the highest-impact safety upgrades for older Twin Cities homes and doesn't require opening every wall in the house.

How many smoke detectors does my home actually need?

Minnesota code requires at minimum one smoke detector inside every bedroom, one outside each sleeping area, and one on every level of the home including the basement. For a typical two-story Twin Cities home with three bedrooms, that's usually 6–7 detectors minimum. Many older homes have far fewer than that. We'll walk through your home and tell you exactly what's required and what you have.

Serving the Twin Cities Metro

Norske Electric serves homeowners throughout the Minneapolis–St. Paul metro area, including Apple Valley, Bloomington, Brooklyn Park, Burnsville, Eagan, Eden Prairie, Excelsior, Golden Valley, Lakeville, Maple Grove, Medina, Minnetonka, Orono, Plymouth, and Savage. Our licensed, bonded, and insured electricians dispatch from our offices in Hamel and Savage and respond quickly to projects of every size. Call (952) 443-4113 for a free estimate or to schedule service.