First Alert HD6135FB Hardwired Heat Alarm with Battery Backup | 135°F & Rate-of-Rise Sensing

Reliable heat detection for spaces where smoke alarms aren’t suitable

The First Alert HD6135FB hardwired heat alarm is designed for places like attached garages, crawl spaces, and laundry rooms where standard smoke detectors may not fit. It responds to either a fixed temperature of 135°F or a rapid temperature rise of more than 15°F in a minute, helping you stay alerted to potential heat events even when visibility is low. The 85-decibel horn delivers a clear, unwavering signal that can be heard throughout nearby living spaces, giving you time to assess the situation calmly.

Built for real‑life use, this device combines hands‑free reliability with practical controls. A microprocessor keeps nuisance alarms to a minimum, and the unit’s test/silence button makes routine checks straightforward. If you prefer hands‑free operation, most household remote controls can trigger testing or silencing, so you can confirm functionality without reaching for the alarm itself.

Key benefits and how they translate to daily use

• Strategic placement: Specifically designed for locations where smoke alarms aren’t feasible, such as garages and utility areas.
• Dual sensing: Fixed 135°F threshold pairs with rate‑of‑rise detection to capture heat events that develop quickly.
• Reduced nuisance alarms: Microprocessor‑driven logic minimizes false alerts, helping you focus on genuine warnings.

• Power resilience: 120‑volt AC operation with a 9‑volt battery backup keeps you protected during outages.
• Interconnectivity: Connect up to 12 alarm units and 6 other devices, so one alarm can wake the whole system.
• Clear identification: A latching indicator shows which unit initiated the alarm for quick response.

Installation and remote operation

Mounting is straightforward with an intuitive bracket, and an accessible battery drawer makes replacements simple. The unit’s test/silence button is easy to reach, and, when paired with a compatible remote control, you can silence or test from across the room. The HD6135FB is UL‑listed and includes a 10‑year limited warranty for peace of mind.

In homes with multiple First Alert or BRK hardwired alarms, this heat alarm can integrate to create a cohesive safety network. When one unit sounds, all interconnected alarms rouse, helping you notice the event sooner and respond thoughtfully. This product combines dependable heat sensing with practical features to support everyday safety decisions in spaces where traditional smoke detectors aren’t the best fit.