Hardwired, Interconnected, Code-Compliant
Smoke & CO Detector Installation
California requires working smoke and CO detectors in specific locations throughout your home. We install hardwired, interconnected systems with battery backup — properly placed, properly wired, and fully code-compliant.
Get Help Fast →What the Law Requires
California has specific rules about where detectors go, how they connect, and when they need replacement. Here's what you need to know.
Smoke Detectors Required In
Every bedroom, hallway adjacent to bedrooms, and every floor including the basement. California law — not optional.
CO Detectors Required In
Near every sleeping area and on every floor with gas appliances or an attached garage. Carbon monoxide is odorless — detectors are the only warning.
Hardwired + Battery Backup
Required in all new construction and major remodels. Battery-only detectors are allowed in existing homes without permit work, but hardwired is safer.
Interconnected Systems
When one detector triggers, every detector in the house sounds the alarm. Required in new builds — and strongly recommended in all homes.
Replacement Schedule
Smoke detectors expire after 10 years. CO detectors expire after 5-7 years. Check the manufacture date on the back — if there's no date, it's overdue.
Combo Smoke/CO Units
Combined detectors cover both hazards in one device. Fewer ceiling units, same protection. Nest Protect and First Alert OneLink are popular choices.
Assessment to Protection
From home walkthrough to full system test — most homes completed in a single visit.
Home Assessment
We walk your home, count existing detectors, check expiration dates, and map every location required by California code.
Equipment Selection
Choose from Kidde, First Alert, or Nest Protect based on your goals — basic code compliance, smart alerts, or whole-home interconnection.
Wiring & Installation
Run new wiring where needed, mount detectors in correct locations, wire the interconnection loop, and connect battery backup.
Full System Test
Trigger every detector to confirm interconnection works. Walk you through maintenance, testing schedule, and replacement timeline.
Why Fox for Detector Installation
California Code Experts
We know exactly where detectors go, how they interconnect, and what triggers code requirements. No guessing — installed right the first time.
Hardwired Interconnection
We wire detectors together so one alarm triggers them all. Battery-only detectors in isolated rooms miss the point — interconnection saves lives.
132 Five-Star Reviews
5.0 Google rating from 132 reviews. Every job gets the same attention — from a single detector swap to a whole-home system.
Licensed C-10 Contractor
CSLB #1145945, fully insured and bonded. All installations to NEC and California Fire Code standards.
Insurance & Resale Ready
Proper documentation for insurance claims and home sales. Many insurers now require hardwired, interconnected detectors for renewal.
12-Month Warranty
All workmanship warrantied for 12 months. If a detector we installed has a wiring issue, we come back and fix it free.
Detector Questions
How do I know if my detectors are expired?
Check the manufacture date on the back of each unit. Smoke detectors last 10 years, CO detectors 5-7 years. No date visible? It's almost certainly expired. Yellowed plastic is another sign of age.
Are battery-only detectors legal in California?
In existing homes with no permit work being done — yes, battery detectors are legal. But if you're doing any permitted work (remodel, panel upgrade, addition), California code requires hardwired detectors with battery backup in the affected areas.
Do all my detectors need to be interconnected?
In new construction and major remodels — yes, interconnection is required. In existing homes without permit work — not required by law, but we strongly recommend it. When a detector in the basement triggers, you want to hear it in the bedroom.
What brands do you install?
Kidde and First Alert for standard hardwired detectors. Nest Protect for smart homes — it self-tests monthly, sends phone alerts, tells you which room has the alarm, and distinguishes between smoke and CO. We recommend Nest Protect for most homes.
How much does detector installation cost?
Replacement on existing wiring: $75-$125 per detector. New hardwired installation: $150-$300 per detector including wiring. Whole-home package (3-bedroom, 6-8 detectors): $600-$1,200. Free estimates — call (650) 550-0719.
Will this pass a home inspection?
Yes. We install to current California code with proper placement, interconnection, and hardwired power with battery backup. We can provide documentation for real estate transactions and insurance.
How long does installation take?
Replacing existing detectors: 1-2 hours. Full hardwired install for a 3-bedroom home: 3-5 hours. Most jobs completed in a single visit.
Get in Touch
Detectors Expired or Missing?
Free home assessment. (650) 550-0719 — we'll map every location your home needs and quote on the spot.
Free estimates · Troubleshooting $90/hr · Safety inspection pricing — ask our team
(650) 550-0719