Smoke Detector Installation in Bellevue WA

Smoke Detector Installation Cost in Bellevue, WA

Washington State requires hardwired, interconnected smoke detectors in all bedrooms, outside each sleeping area, and on every level of a home. Battery-only detectors do not meet code for new installs or replacements in Bellevue. Installing a hardwired smoke detector costs $100–$175 per unit, with most whole-home jobs running $300–$600 for a typical 3–4 bedroom home.

Why Hardwired Detectors?

Hardwired detectors are interconnected — when one sounds, they all sound. In a two-story Bellevue home, you'll hear an alarm triggered in the basement from the master bedroom upstairs. Battery-only detectors operate independently, which means a fire in the garage may not wake you in a back bedroom. Hardwired units also have battery backup so they work during a power outage.

Replacing Old or Expired Detectors

Smoke detectors expire after 10 years. If your Bellevue home has original detectors from a 2000s–2010s build, they may be due for replacement regardless of whether they're chirping. Replacing an existing hardwired detector with a new compatible unit: $100–$150 per unit. We match the connector type so existing wiring can be reused.

Combination Smoke + CO Detectors

Washington code now requires CO detectors on each level of any home with an attached garage, gas appliances, or fuel-burning heating. Combination smoke/CO units cost slightly more but reduce the total number of devices needed. We install Kidde and First Alert combination units. Cost: $125–$175 per unit installed.

Adding Detectors to Rooms That Don't Have Them

Older Bellevue homes sometimes have gaps in coverage — no detector in a bedroom addition, a bonus room over the garage, or a finished basement. Running wiring to a new location and installing a detector: $175–$300 per new location depending on wire run distance.

Cost Summary — Bellevue WA

• Replace existing hardwired detector: $100–$150 per unit
• Smoke + CO combination unit: $125–$175 per unit
• New location (new wiring run): $175–$300 per unit
• Whole-home replacement (3–4 bed): $300–$600 total

Our detectors were all original from 2008. They replaced five units with Kidde combination smoke/CO detectors in about 90 minutes. Everything is interconnected and up to code.

- Bellevue homeowner, May 2026

Schedule Smoke Detector Service in Bellevue

Smoke detector installs are quick and we can usually get to Bellevue same day or next day. Call 425-210-4791 or get a free estimate online. We also serve Sammamish, Newcastle, Kirkland, and Renton.