First Alert GCO1 Combination CO and Explosive Gas Alarm Review (4.2/5) | WC Safety
First Alert GCO1 Combination CO and Explosive Gas Alarm Review
Model GCO1XP | Reviewed by Steve Thompson | WC Safety
Bottom line: The GCO1 is First Alert's answer to a common household need: CO and combustible gas protection in a single plug-in unit. If you have a gas range, gas furnace, gas water heater, or propane appliances, the GCO1 covers both CO and explosive gas risk from a single outlet. The 5-year warranty is shorter than CO-only models, and optimal placement for natural gas versus propane differs but as a kitchen or utility room alarm near gas appliances, the GCO1 is the most practical dual-sensor option First Alert makes.
Pros
- Dual detection: CO + natural gas, propane, and methane
- Digital display shows real-time CO concentration (PPM)
- 9V battery backup works through power outages
- AC plug-in continuous power for always-on sensing
- 85 dB alarm
- Suitable for kitchens, utility rooms, garages
Cons
- 5-year warranty shorter than CO-only models
- Natural gas and propane require different height placement
- Higher price than CO-only plug-in alarms
- No wireless interconnect
- 9V battery backup (vs. AA in CO615) depletes faster under load
- Larger form factor than standard CO alarms
How we evaluate combination CO/gas alarms: We assess dual-sensor utility, placement practicality, battery backup reliability, warranty duration relative to sensor lifespan, UL certifications, and value vs. deploying separate CO and gas detectors. Dual-sensor alarms earn credit when they consolidate meaningful risk coverage without requiring multiple outlets or units.
Verdict: 4.2 / 5
The GCO1 fills a real gap for households with gas appliances a single outlet-based unit that monitors CO and combustible gases simultaneously. The digital CO display adds diagnostic value. The 9V battery backup handles outages. The main trade-off is the 5-year warranty (shorter than standalone CO alarms) and the inherent placement tension between natural gas (rises) and propane (sinks). For a kitchen near a gas range or a utility room near a gas furnace, the GCO1 is the right First Alert choice. In rooms without gas appliances, a CO-only alarm is more cost-effective. View the GCO1 at WC Safety or check current price on Amazon.
| Specification | GCO1 (GCO1XP) |
|---|---|
| Power source | 120V AC plug-in |
| Battery backup | 9V alkaline battery |
| Display | Backlit digital real-time CO PPM |
| Gases detected | Carbon monoxide + natural gas, propane, methane |
| Alarm output | 85 dB |
| Interconnectable | No |
| Dimensions | 5.6" W x 3.1" H x 1.8" D |
| Warranty | 5-year limited |
Frequently Asked Questions
What gases does the GCO1 detect?The GCO1 detects carbon monoxide (CO) and combustible gases including natural gas (methane), propane, and other flammable hydrocarbons. The CO sensor uses electrochemical technology and measures concentration in PPM. The combustible gas sensor detects explosive gases at concentrations below the lower explosive limit (LEL) alerting before levels reach ignition thresholds. This dual-sensor design makes it appropriate for rooms where gas appliances create risk from both CO poisoning and gas leak ignition.
The GCO1 detects carbon monoxide (CO) and combustible gases including natural gas (methane), propane, and other flammable hydrocarbons. The CO sensor uses electrochemical technology and measures concentration in PPM. The combustible gas sensor detects explosive gases at concentrations below the lower explosive limit (LEL) alerting before levels reach ignition thresholds. This dual-sensor design makes it appropriate for rooms where gas appliances create risk from both CO poisoning and gas leak ignition.
Where should the GCO1 be installed?Install the GCO1 near gas appliances: kitchen (near gas range or oven), utility room (near gas furnace or water heater), or garage (near gas-powered equipment or vehicles). Natural gas (methane) is lighter than air and rises toward the ceiling, while propane is heavier than air and sinks toward the floor no single height is ideal for both. For homes with natural gas only, mount the GCO1 higher on the wall near the outlet. For propane homes, lower placement is preferred. Consult local codes for specific requirements.
Install the GCO1 near gas appliances: kitchen (near gas range or oven), utility room (near gas furnace or water heater), or garage (near gas-powered equipment or vehicles). Natural gas (methane) is lighter than air and rises toward the ceiling, while propane is heavier than air and sinks toward the floor no single height is ideal for both. For homes with natural gas only, mount the GCO1 higher on the wall near the outlet. For propane homes, lower placement is preferred. Consult local codes for specific requirements.
Does the GCO1 protect during a power outage?Yes. The 9V battery backup activates automatically when AC power is lost. CO incidents frequently occur during power outages when homeowners run generators, gas grills, or portable heaters indoors exactly the scenario requiring a functioning alarm. Replace the 9V backup battery annually to ensure it's at full charge when needed.
Yes. The 9V battery backup activates automatically when AC power is lost. CO incidents frequently occur during power outages when homeowners run generators, gas grills, or portable heaters indoors exactly the scenario requiring a functioning alarm. Replace the 9V backup battery annually to ensure it's at full charge when needed.
Why is the GCO1 warranty only 5 years when CO-only alarms have 7-10 year warranties?The GCO1's dual-sensor design an electrochemical CO sensor plus a combustible gas sensor adds complexity that affects the rated service life. The combustible gas sensor component has a shorter reliable service life than a CO-only electrochemical sensor. The 5-year warranty reflects this; plan to replace the GCO1 at 5-7 years to ensure both sensors are operating within their reliable detection range.
The GCO1's dual-sensor design an electrochemical CO sensor plus a combustible gas sensor adds complexity that affects the rated service life. The combustible gas sensor component has a shorter reliable service life than a CO-only electrochemical sensor. The 5-year warranty reflects this; plan to replace the GCO1 at 5-7 years to ensure both sensors are operating within their reliable detection range.
How does the GCO1 compare to the Kidde KN-COEG-3?Both are plug-in CO + explosive gas combination alarms with digital displays and battery backup. The Kidde KN-COEG-3 is the predecessor to the Kidde COPDLG; if you're choosing between brands, compare current pricing. The GCO1's 5-year warranty is shorter than comparable Kidde models. In terms of functionality CO + gas detection, digital display, AC plug-in with backup the products are broadly equivalent. Brand ecosystem compatibility (if you have other First Alert or Kidde alarms already) may be the deciding factor.
Both are plug-in CO + explosive gas combination alarms with digital displays and battery backup. The Kidde KN-COEG-3 is the predecessor to the Kidde COPDLG; if you're choosing between brands, compare current pricing. The GCO1's 5-year warranty is shorter than comparable Kidde models. In terms of functionality CO + gas detection, digital display, AC plug-in with backup the products are broadly equivalent. Brand ecosystem compatibility (if you have other First Alert or Kidde alarms already) may be the deciding factor.
Should I use the GCO1 in every room, or only near gas appliances?Use the GCO1 specifically where gas appliances create direct risk kitchen, utility room, garage with gas equipment. In bedrooms and living areas without gas appliances, a standard CO-only alarm like the First Alert CO615 or CO710 is more appropriate and more cost-effective. The GCO1's dual-sensor is an asset near gas sources; it's unnecessary and over-spec for rooms where only CO (from a distant furnace or attached garage) is the primary concern.
Use the GCO1 specifically where gas appliances create direct risk kitchen, utility room, garage with gas equipment. In bedrooms and living areas without gas appliances, a standard CO-only alarm like the First Alert CO615 or CO710 is more appropriate and more cost-effective. The GCO1's dual-sensor is an asset near gas sources; it's unnecessary and over-spec for rooms where only CO (from a distant furnace or attached garage) is the primary concern.
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