Smoke and carbon monoxide detectors are among the most important safety devices in a home — and among the most neglected. Mid Penn Electric installs hardwired, interconnected smoke and CO detector systems for homeowners throughout Lebanon, Lancaster, and Dauphin counties. We also replace aging detectors that have passed their service life, which is more common than most homeowners realize.
Why Hardwired Detectors Matter
Hardwired detectors run continuously on household power with a battery backup — they do not depend on a battery that can die silently. More importantly, hardwired detectors can be interconnected, so when one detects smoke or carbon monoxide, all alarms in the home sound simultaneously. That interconnection is the critical difference in a large home: a detector in the basement triggering an alarm in an upstairs bedroom can be the difference between waking up and not. Battery-only detectors alarm independently, which means the alarm closest to the danger may sound while the rest of the home remains silent.
We recently replaced a full set of aging battery detectors in a Lebanon, PA home with hardwired, interconnected combination smoke and CO units positioned per current code requirements. Read that story: Smoke and CO Detector Upgrade in Lebanon, PA.
Frequently Asked Questions
How often should smoke and carbon monoxide detectors be replaced?
Smoke detectors should be replaced every ten years. Carbon monoxide detectors have a shorter lifespan — typically five to seven years. The manufacture date is stamped on the back of each unit. Even if a detector sounds when tested, the test button only checks the horn and battery, not the sensing chamber. Sensing components degrade over time and may not respond adequately to a real event. If you do not know when your detectors were installed, check the back — if the date is missing or the unit is more than a decade old, it should be replaced.
Where should smoke and CO detectors be placed in a home?
The NEC and NFPA 72 require smoke detectors inside every bedroom, outside each sleeping area, and on every level of the home including the basement. Carbon monoxide detectors are required outside each sleeping area and on every level with a fuel-burning appliance or attached garage. Combination smoke and CO units satisfy both requirements in a single device, which is what we install in most applications.
Can hardwired detectors be added to a home that only has battery-operated units?
Yes. Adding hardwired detectors requires running wiring from the electrical panel to each detector location and connecting the interconnect wire that links them all together. In a finished home this involves some wall and ceiling work, but we minimize disruption wherever possible. The result — continuously powered, interconnected detectors throughout the home — is well worth the effort.