The Kidde P9040 is a compact 4-inch diameter battery-powered photoelectric smoke alarm, ideal for spaces where a standard-size alarm is too large. The photoelectric sensor detects visible smoke particles associated with slow-smoldering fires. A test button verifies the electronics and horn, and a low battery warning chirp alerts users when the 9V battery needs replacement. The P9040 has been replaced by the Kidde 10SDR.
Why would I choose a 4-inch smoke alarm over a standard size?
A 4-inch alarm like the P9040 is ideal for spaces with low ceilings, tight alcoves, or where a standard 5-6 inch alarm looks too large. It provides the same protection in a more compact footprint.
What sensor does the P9040 use?
The P9040 uses photoelectric sensing technology, which detects visible smoke particles from slow-smoldering fires. This makes it well-suited for bedrooms and living areas where smoldering fires are more common.
What battery does the P9040 require?
The P9040 uses a 9V alkaline battery. A low battery warning chirp will sound when the battery needs replacement. Always use a fresh, quality battery for reliable protection.
Is there a newer version of the P9040?
Yes. The P9040 has been replaced by the Kidde 10SDR, a DETECT-line 4-inch photoelectric smoke alarm with improved sensing and AA battery power.
Where should I install the P9040?
Install the P9040 on the ceiling or wall in every bedroom, outside each sleeping area, and on every level of the home per NFPA 72 guidelines. Its compact 4-inch size makes it ideal for smaller rooms or low-ceiling spaces.
# Kidde Battery Operated 4-Inch Photoelectric Smoke Alarm **Model:** `P9040` **Brand:** Kidde **Category:** Smoke Alarm Photoelectric > The Kidde P9040 is a compact 4-inch diameter battery-powered photoelectric smoke alarm, ideal for spaces where a standard-size alarm is too large. The photoelectric sensor detects visible smoke particles associated with slow-smoldering fires. A test button verifies the electronics and horn, and a low battery warning chirp alerts users when the 9V battery needs replacement. The P9040 has been replaced by the Kidde 10SDR. ## Specifications | Attribute | Value | |---|---| | Product Type | Smoke Alarm | | Alarm Type | smoke | | Sensor Smoke | photoelectric | | Power Source | battery-aa | | Battery Backup | No | | Battery Type | 9V | | Battery Replaceable | Yes | | Voice Alerts | No | | Smart Wifi | No | | App Connected | No | | Ring Ecosystem | No | | Interconnect | No | | Interconnect Type | none | | Wire Free Rf | No | | Self Testing | Yes | | Hush Feature | No | | Smart Hush | No | | Strobe | No | | Egress Light | No | | Alarm Db | 85 | | Ul Smoke | UL 217 | | Warranty Years | 10 | ## What's Included - alarm unit - 9V battery - mounting hardware - quick install guide Source: https://www.jaspecs.com/kidde/smoke-alarm-photoelectric/p9040-kidde-battery-4inch-photoelectric-smoke-alarm/