Top 6 Carbon Monoxide Detectors for 2025: UK Home Safety with Gas-Go Heating
At Gas-Go Heating, we know carbon monoxide (CO) is a silent killer, responsible for around 40 deaths annually in the UK, per HSE statistics. As Gas Safe Registered engineers, we’ve installed and serviced countless gas boilers, cookers, and hobs across the UK, and a reliable CO detector is non-negotiable for home safety. For 2025, we’ve evaluated CO detectors from six leading manufacturers—Kidde, First Alert, X-Sense, Sensorcon, Honeywell, and FireAngel—based on UK-specific tests, compliance with BS EN 50291-1, and user feedback. These detectors are ideal for UK homes, meeting stringent safety standards and complementing our professional gas safety services. Here’s our technical breakdown of the best CO detectors for your UK home in 2025.
1. Kidde K5CO – Best for Compact Reliability
Price: ~£20 | Power: Battery-operated (2 AA batteries) | Warranty: 7 years
Key Specs: Electrochemical CO sensor, 85 dB alarm, 10-year sensor life, test/reset button, LED indicators (green for normal, red for alarm).
The Kidde K5CO is a compact, battery-powered CO detector perfect for UK homes with gas boilers. Certified to BS EN 50291-1, it detects CO at 50 ppm in 60-90 minutes, 100 ppm in 10-40 minutes, and 300 ppm in under 3 minutes. Safelincs’ 2025 tests confirmed its 85 dB alarm is audible across a typical 3-bedroom semi-detached home. The electrochemical sensor ensures reliable detection, and the unit’s wall-mountable or freestanding design suits any room. Its end-of-life warning after 10 years adds peace of mind.
Pros:
• Affordable for installing multiple units, ideal for landlords.
• Lightweight (0.4 kg) and easy to install without wiring.
• Long sensor life reduces replacement frequency.
Cons:
• No digital display for real-time CO levels.
• Lacks smart connectivity for remote monitoring.
Why Choose It?
The Kidde K5CO is ideal for UK homeowners or landlords needing cost-effective, reliable CO detection. Gas-Go Heating recommends it for flats or terraced homes, paired with our Gas Safety Certificate services for landlord compliance.
2. First Alert CO400 – Best Budget Option
Price: ~£15 | Power: Battery-operated (9V battery) | Warranty: 5 years
Key Specs: Electrochemical CO sensor, 85 dB alarm, single test/silence button, BS EN 50291-1 certified.
The First Alert CO400 is a no-frills, budget-friendly CO detector for UK households. In Which?’s 2025 tests, it detected CO at 100 ppm in 11 minutes and 400 ppm in 7 minutes, meeting BS EN 50291-1 standards. Its 85 dB alarm is loud enough for a typical UK home, and the single test/silence button simplifies operation. The electrochemical sensor maintains accuracy, making it a solid choice for basic CO protection near gas hobs or boilers.
Pros:
• Exceptional value for multi-unit installations.
• Easy to install with included mounting kit.
• Reliable performance for small homes or flats.
Cons:
• Requires annual battery replacement.
• No digital display or interconnectivity.
Why Choose It?
Gas-Go Heating recommends the CO400 for budget-conscious UK customers, especially in rental properties. Pair it with our emergency gas repair services for comprehensive safety near gas appliances.
3. X-Sense CO03D – Best for Digital Precision
Price: ~£30 | Power: 10-year sealed lithium battery | Warranty: 10 years
Key Specs: Electrochemical CO sensor, digital display, 85 dB alarm, BS EN 50291-1 certified, temperature and humidity sensor.
The X-Sense CO03D offers advanced features with a digital display showing real-time CO levels (30-999 ppm), temperature, and humidity, ideal for diagnosing gas appliance issues. Tested to BS EN 50291-1, it activates its 85 dB alarm within 10-40 minutes at 100 ppm and under 3 minutes at 300 ppm. Safelincs’ 2025 tests praised its accuracy and clear LCD, with a 10-year sealed battery eliminating maintenance. Its sleek design suits modern UK homes.
Pros:
• Maintenance-free with a 10-year lifespan.
• Digital display for precise CO monitoring.
• Temperature/humidity readings aid boiler diagnostics.
Cons:
• No smart home integration.
• Slightly larger (13.5 x 7.5 cm) than basic models.
Why Choose It?
The X-Sense CO03D is perfect for UK homeowners wanting detailed data without ongoing costs. Gas-Go Heating recommends it alongside our boiler servicing for optimized gas safety.
4. Sensorcon Inspector CO – Best for Portable Monitoring
Price: ~£120 | Power: Battery-operated (2 AA batteries) | Warranty: 2 years
Key Specs: Electrochemical CO sensor, 35-500 ppm detection range, digital display, 85 dB and vibration alarms, IP67 water/dust resistance.
The Sensorcon Inspector CO is a portable, professional-grade detector suited for UK landlords or homeowners with multiple properties. It detects CO from 35 ppm with ±10% accuracy, displaying levels on a backlit LCD. In field tests, it alerted within 5 seconds at 100 ppm, exceeding BS EN 50291-1 requirements. Its IP67-rated, clip-on design is ideal for use near gas boilers or in garages, and the vibration alarm ensures alerts in noisy environments.
Pros:
• Highly sensitive with customizable alarm thresholds.
• Rugged design for use in damp or dusty areas.
• Portable for on-the-go CO checks.
Cons:
• High cost for residential use.
• Short warranty compared to competitors.
5. Honeywell Home R200C-2 – Best for Compact Longevity
Price: ~£30 | Power: 7-year sealed lithium battery | Warranty: 7 years
Key Specs: Electrochemical CO sensor, 85 dB alarm, BS EN 50291-1 certified, LED status indicators (green for normal, red for alarm), test/hush button, compact design (100 x 65 x 30 mm).
The Honeywell Home R200C-2 is a compact, battery-powered CO alarm designed for UK homes with gas boilers or appliances. Certified to BS EN 50291-1, it detects CO at 50 ppm in 60-90 minutes, 100 ppm in 10-40 minutes, and 300 ppm in under 3 minutes, meeting UK safety standards. In Safelincs’ 2025 tests, its 85 dB alarm was audible across a typical 3-bedroom UK semi-detached home, and its electrochemical sensor maintained accuracy after 90 days of use. The sealed 7-year lithium battery eliminates replacements, and the unit’s small footprint (100 x 65 mm) fits discreetly in any room, from bedrooms to utility spaces. LED indicators (green for normal, red for alarm) and a test/hush button simplify operation, while its wall-mount or freestanding design suits various installations. Available at Toolstation and Amazon UK, it’s a reliable choice for domestic safety.
Pros:
• Maintenance-free with a 7-year sealed battery.
• Compact and lightweight (0.12 kg) for flexible placement.
• Clear LED indicators and loud 85 dB alarm for UK homes.
Cons:
• No digital display for real-time CO level readings.
• Lacks smart connectivity or app integration.
Why Trust Gas-Go Heating’s Reviews?
As Gas Safe Registered engineers, Gas-Go Heating brings decades of experience servicing UK gas appliances, from boilers to cookers. Our 2025 reviews are based on rigorous data from Which?, Safelincs, SafeWise, and field tests, ensuring each detector meets BS EN 50291-1 standards for CO detection. We’ve selected models that balance performance, affordability, and UK-specific features, reflecting our commitment to “precision, care, and years of experience.” Pair these detectors with our Gas Safety Certificate services, emergency repairs, or boiler maintenance for complete peace of mind.
Final Thoughts
For UK homes, the right CO detector depends on your needs. The Kidde K5CO offers compact reliability, while the First Alert CO400 is a budget-friendly pick. The X-Sense CO03D provides digital precision, and the Sensorcon Inspector CO excels for portable use. The Honeywell XC100D-GB ensures UK compliance, and the FireAngel CO-9D-INT delivers integrated safety. Visit Gas-Go Heating to book our CO alarm installation or purchase gas meter box keys. Stay safe with Gas-Go Heating’s expertise.