Wisualarm Carbon Monoxide Alarm | 10-Year Sealed Battery | LCD Display
Standalone 10-Year Sealed Battery
The Wisualarm DHI-HY-GC20D is a standalone carbon monoxide alarm with a 10-year sealed 3V CR123A lithium battery — designed to provide a full decade of continuous protection with zero battery maintenance. It uses a high-performance Figaro electrochemical CO sensor, recognised as one of the most reliable and accurate sensor technologies for domestic CO detection, and is certified to EN 50291-1:2018 — the current British and European standard for residential CO alarms. An integrated LCD display shows live CO concentration in ppm, combined with a >85dB audible alarm and visual LED indicator, gives occupants clear real-time information when it matters most. A single-button test and silence function makes routine testing and false-alarm management simple.
🏠 UK Legal Requirement — Smoke and Carbon Monoxide Alarm (Amendment) Regulations 2022: Since 1 October 2022, private sector landlords in England are legally required to install a CO alarm in any room with a fixed combustion appliance (excluding gas cookers). This includes rooms with gas boilers, gas fires, oil boilers, solid fuel stoves and open fireplaces. Social landlords have been subject to the same requirement since 1 February 2023. The DHI-HY-GC20D, certified to EN 50291-1:2018, meets the technical standard required to comply with this legislation. Similar requirements apply in Scotland, Wales and Northern Ireland under their respective regulations.
Key Features
Where to Install
CO alarms should be installed wherever a combustion appliance is present and wherever occupants sleep. The following guidance is based on BS EN 50292 (the installation standard that accompanies EN 50291) and HSE recommendations:
- Every room with a fixed combustion appliance — gas or oil boiler, gas fire, wood-burning stove, open fireplace, log burner, or pellet stove. The alarm should be on the same level as the appliance, within 1–3 metres where possible.
- Each sleeping level of the home — CO is particularly dangerous at night when occupants cannot self-evacuate. An alarm in or adjacent to sleeping areas provides the earliest possible warning.
- Mounting height — CO has a similar density to air and disperses evenly. EN 50292 recommends mounting on a wall or ceiling. Wall mounting: between 1.5m and 2.1m above the floor. Ceiling mounting: as per manufacturer instructions (minimum 300mm from walls/corners).
- Avoid — direct sunlight, areas of high humidity (bathrooms, directly above cookers), areas with strong airflow (directly next to windows, fans or air conditioning vents), and garages or enclosed parking areas (vehicle exhaust will trigger the alarm).
Standalone vs Wireless Interconnected — Which Variant?
| Feature | DHI-HY-GC20D ★ (this product) Standalone |
DHI-HY-GC20D-R8 Wireless Interconnected |
|---|---|---|
| Wireless interconnection | ✗ No | ✓ Yes — up to 24 Wisulink devices |
| App / smart home integration | ✗ No | ✓ Optional — via DHI-HY-GW01A Gateway |
| Battery | 10-year sealed CR123A (non-replaceable) | 10-year sealed CR123A (non-replaceable) |
| LCD CO display | ✓ Yes | ✓ Yes |
| Alarm volume | >85dB @ 3m | >85dB @ 3m |
| EN 50291-1:2018 certified | ✓ Yes | ✓ Yes |
| Operating temperature | -10°C to +40°C | -10°C to +55°C |
| Best for | Single-room compliance, simple installs, rental properties, cost-effective standalone protection | Multi-room or whole-home coverage, properties where alarm in one room should sound all alarms, smart monitoring via app |
⚠️ Carbon monoxide — know the symptoms: CO is colourless and odourless — it cannot be detected by the senses alone. Symptoms of CO poisoning include headache, dizziness, nausea, breathlessness and confusion. If your CO alarm sounds: do not ignore it. Open windows and doors, evacuate immediately, do not re-enter until declared safe by the emergency services or gas-safe engineer. Call the Gas Emergency number: 0800 111 999.
Technical Specifications
| Specification | Detail |
|---|---|
| Product Identity | |
| Model number | DHI-HY-GC20D |
| Brand | Wisualarm (by Dahua) |
| Variant | Standalone (non-wireless) |
| Detection | |
| Sensor type | Electrochemical (Figaro) |
| Gas detected | Carbon monoxide (CO) |
| Sensor life | 10 years |
| Alarm Output | |
| Alarm volume | Over 85dB(A) at 3 metres |
| Alarm mode | Visual (LED) and audible |
| Silence function | Supported |
| Silence duration | Approximately 45 seconds |
| Display | LCD — live CO concentration (ppm) and peak-level memory |
| Power | |
| Power source | 3V CR123A lithium battery (non-replaceable, sealed) |
| Battery life | 10 years |
| Low battery warning | Yes |
| End-of-life warning | Yes |
| Environmental | |
| Usage environment | Indoor use only |
| Operating temperature | -10°C to +40°C (+14°F to +104°F) |
| Relative humidity | ≤95% RH (non-condensing) |
| Physical | |
| Dimensions (L × W × H) | 116.4 × 71.7 × 28.3mm (4.58" × 2.82" × 1.11") |
| Weight | 125g |
| Housing material | PC + ABS |
| Installation method | Wall mount |
| Certifications & Standards | |
| Standard compliance | EN 50291-1:2018 |
| Certifications | TÜV, CE |
| Wireless interconnection | Not supported (standalone only) |
FAQs
Does this alarm comply with the Smoke and Carbon Monoxide Alarm Regulations 2022?
Yes. The DHI-HY-GC20D is certified to EN 50291-1:2018, which is the standard specified in the statutory guidance accompanying the Smoke and Carbon Monoxide Alarm (Amendment) Regulations 2022 (England). It meets the technical requirements for a compliant CO alarm for private and social rented properties. The regulations require CO alarms in rooms with fixed combustion appliances (excluding gas cookers); this alarm is appropriate for those locations when used as a standalone unit. For properties requiring interconnected alarms across multiple rooms (e.g. to meet Scottish regulations under the Housing (Scotland) Act 2006), the wireless DHI-HY-GC20D-R8 variant should be considered.
Can the battery be replaced when it runs low?
No — the battery is permanently sealed within the unit and is not designed to be replaced. This is a deliberate safety feature: the sealed design ensures the alarm cannot be inadvertently disabled by battery removal, and the 10-year service life is matched to the sensor's operational lifespan. When the end-of-life warning sounds (typically after 10 years), the entire unit should be replaced. This is consistent with BS EN 50291 guidance on CO alarm replacement intervals.
What is the difference between this and the DHI-HY-GC20D-R8?
The DHI-HY-GC20D (this product) is a standalone alarm — it operates independently, with no wireless connectivity to other alarms. It is the simpler, lower-cost option for single-room CO protection or for properties where interconnection is not required. The DHI-HY-GC20D-R8 adds Wisulink RF wireless interconnection, allowing it to communicate with up to 24 other Wisualarm devices (smoke alarms, heat alarms, CO alarms) — when one triggers, all sound simultaneously. It can also be connected to the optional Wisualarm Gateway (DHI-HY-GW01A) for smartphone app alerts. Both share the same Figaro electrochemical sensor, LCD display and 10-year sealed battery.
My alarm is beeping briefly every minute — is this an emergency?
A single brief beep every 30–60 seconds typically indicates either a low battery warning or an end-of-life signal — not a CO alarm event. A CO alarm triggers a continuous or rapid pattern of beeps. Refer to the user manual for the specific beep pattern meanings for this model. If the rapid alarm pattern sounds, treat it as a CO emergency, evacuate, and call the gas emergency line (0800 111 999) — do not assume it is a false alarm without investigation by a qualified engineer.
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Wisualarm Carbon Monoxide Alarm | 10-Year Sealed Battery | LCD Display
Standalone 10-Year Sealed Battery
The Wisualarm DHI-HY-GC20D is a standalone carbon monoxide alarm with a 10-year sealed 3V CR123A lithium battery — designed to provide a full decade of continuous protection with zero battery maintenance. It uses a high-performance Figaro electrochemical CO sensor, recognised as one of the most reliable and accurate sensor technologies for domestic CO detection, and is certified to EN 50291-1:2018 — the current British and European standard for residential CO alarms. An integrated LCD display shows live CO concentration in ppm, combined with a >85dB audible alarm and visual LED indicator, gives occupants clear real-time information when it matters most. A single-button test and silence function makes routine testing and false-alarm management simple.
🏠 UK Legal Requirement — Smoke and Carbon Monoxide Alarm (Amendment) Regulations 2022: Since 1 October 2022, private sector landlords in England are legally required to install a CO alarm in any room with a fixed combustion appliance (excluding gas cookers). This includes rooms with gas boilers, gas fires, oil boilers, solid fuel stoves and open fireplaces. Social landlords have been subject to the same requirement since 1 February 2023. The DHI-HY-GC20D, certified to EN 50291-1:2018, meets the technical standard required to comply with this legislation. Similar requirements apply in Scotland, Wales and Northern Ireland under their respective regulations.
Key Features
Where to Install
CO alarms should be installed wherever a combustion appliance is present and wherever occupants sleep. The following guidance is based on BS EN 50292 (the installation standard that accompanies EN 50291) and HSE recommendations:
- Every room with a fixed combustion appliance — gas or oil boiler, gas fire, wood-burning stove, open fireplace, log burner, or pellet stove. The alarm should be on the same level as the appliance, within 1–3 metres where possible.
- Each sleeping level of the home — CO is particularly dangerous at night when occupants cannot self-evacuate. An alarm in or adjacent to sleeping areas provides the earliest possible warning.
- Mounting height — CO has a similar density to air and disperses evenly. EN 50292 recommends mounting on a wall or ceiling. Wall mounting: between 1.5m and 2.1m above the floor. Ceiling mounting: as per manufacturer instructions (minimum 300mm from walls/corners).
- Avoid — direct sunlight, areas of high humidity (bathrooms, directly above cookers), areas with strong airflow (directly next to windows, fans or air conditioning vents), and garages or enclosed parking areas (vehicle exhaust will trigger the alarm).
Standalone vs Wireless Interconnected — Which Variant?
| Feature | DHI-HY-GC20D ★ (this product) Standalone |
DHI-HY-GC20D-R8 Wireless Interconnected |
|---|---|---|
| Wireless interconnection | ✗ No | ✓ Yes — up to 24 Wisulink devices |
| App / smart home integration | ✗ No | ✓ Optional — via DHI-HY-GW01A Gateway |
| Battery | 10-year sealed CR123A (non-replaceable) | 10-year sealed CR123A (non-replaceable) |
| LCD CO display | ✓ Yes | ✓ Yes |
| Alarm volume | >85dB @ 3m | >85dB @ 3m |
| EN 50291-1:2018 certified | ✓ Yes | ✓ Yes |
| Operating temperature | -10°C to +40°C | -10°C to +55°C |
| Best for | Single-room compliance, simple installs, rental properties, cost-effective standalone protection | Multi-room or whole-home coverage, properties where alarm in one room should sound all alarms, smart monitoring via app |
⚠️ Carbon monoxide — know the symptoms: CO is colourless and odourless — it cannot be detected by the senses alone. Symptoms of CO poisoning include headache, dizziness, nausea, breathlessness and confusion. If your CO alarm sounds: do not ignore it. Open windows and doors, evacuate immediately, do not re-enter until declared safe by the emergency services or gas-safe engineer. Call the Gas Emergency number: 0800 111 999.
Technical Specifications
| Specification | Detail |
|---|---|
| Product Identity | |
| Model number | DHI-HY-GC20D |
| Brand | Wisualarm (by Dahua) |
| Variant | Standalone (non-wireless) |
| Detection | |
| Sensor type | Electrochemical (Figaro) |
| Gas detected | Carbon monoxide (CO) |
| Sensor life | 10 years |
| Alarm Output | |
| Alarm volume | Over 85dB(A) at 3 metres |
| Alarm mode | Visual (LED) and audible |
| Silence function | Supported |
| Silence duration | Approximately 45 seconds |
| Display | LCD — live CO concentration (ppm) and peak-level memory |
| Power | |
| Power source | 3V CR123A lithium battery (non-replaceable, sealed) |
| Battery life | 10 years |
| Low battery warning | Yes |
| End-of-life warning | Yes |
| Environmental | |
| Usage environment | Indoor use only |
| Operating temperature | -10°C to +40°C (+14°F to +104°F) |
| Relative humidity | ≤95% RH (non-condensing) |
| Physical | |
| Dimensions (L × W × H) | 116.4 × 71.7 × 28.3mm (4.58" × 2.82" × 1.11") |
| Weight | 125g |
| Housing material | PC + ABS |
| Installation method | Wall mount |
| Certifications & Standards | |
| Standard compliance | EN 50291-1:2018 |
| Certifications | TÜV, CE |
| Wireless interconnection | Not supported (standalone only) |
FAQs
Does this alarm comply with the Smoke and Carbon Monoxide Alarm Regulations 2022?
Yes. The DHI-HY-GC20D is certified to EN 50291-1:2018, which is the standard specified in the statutory guidance accompanying the Smoke and Carbon Monoxide Alarm (Amendment) Regulations 2022 (England). It meets the technical requirements for a compliant CO alarm for private and social rented properties. The regulations require CO alarms in rooms with fixed combustion appliances (excluding gas cookers); this alarm is appropriate for those locations when used as a standalone unit. For properties requiring interconnected alarms across multiple rooms (e.g. to meet Scottish regulations under the Housing (Scotland) Act 2006), the wireless DHI-HY-GC20D-R8 variant should be considered.
Can the battery be replaced when it runs low?
No — the battery is permanently sealed within the unit and is not designed to be replaced. This is a deliberate safety feature: the sealed design ensures the alarm cannot be inadvertently disabled by battery removal, and the 10-year service life is matched to the sensor's operational lifespan. When the end-of-life warning sounds (typically after 10 years), the entire unit should be replaced. This is consistent with BS EN 50291 guidance on CO alarm replacement intervals.
What is the difference between this and the DHI-HY-GC20D-R8?
The DHI-HY-GC20D (this product) is a standalone alarm — it operates independently, with no wireless connectivity to other alarms. It is the simpler, lower-cost option for single-room CO protection or for properties where interconnection is not required. The DHI-HY-GC20D-R8 adds Wisulink RF wireless interconnection, allowing it to communicate with up to 24 other Wisualarm devices (smoke alarms, heat alarms, CO alarms) — when one triggers, all sound simultaneously. It can also be connected to the optional Wisualarm Gateway (DHI-HY-GW01A) for smartphone app alerts. Both share the same Figaro electrochemical sensor, LCD display and 10-year sealed battery.
My alarm is beeping briefly every minute — is this an emergency?
A single brief beep every 30–60 seconds typically indicates either a low battery warning or an end-of-life signal — not a CO alarm event. A CO alarm triggers a continuous or rapid pattern of beeps. Refer to the user manual for the specific beep pattern meanings for this model. If the rapid alarm pattern sounds, treat it as a CO emergency, evacuate, and call the gas emergency line (0800 111 999) — do not assume it is a false alarm without investigation by a qualified engineer.
Product Information
Product Information
Shipping & Returns
Shipping & Returns
Description
Standalone 10-Year Sealed Battery
The Wisualarm DHI-HY-GC20D is a standalone carbon monoxide alarm with a 10-year sealed 3V CR123A lithium battery — designed to provide a full decade of continuous protection with zero battery maintenance. It uses a high-performance Figaro electrochemical CO sensor, recognised as one of the most reliable and accurate sensor technologies for domestic CO detection, and is certified to EN 50291-1:2018 — the current British and European standard for residential CO alarms. An integrated LCD display shows live CO concentration in ppm, combined with a >85dB audible alarm and visual LED indicator, gives occupants clear real-time information when it matters most. A single-button test and silence function makes routine testing and false-alarm management simple.
🏠 UK Legal Requirement — Smoke and Carbon Monoxide Alarm (Amendment) Regulations 2022: Since 1 October 2022, private sector landlords in England are legally required to install a CO alarm in any room with a fixed combustion appliance (excluding gas cookers). This includes rooms with gas boilers, gas fires, oil boilers, solid fuel stoves and open fireplaces. Social landlords have been subject to the same requirement since 1 February 2023. The DHI-HY-GC20D, certified to EN 50291-1:2018, meets the technical standard required to comply with this legislation. Similar requirements apply in Scotland, Wales and Northern Ireland under their respective regulations.
Key Features
Where to Install
CO alarms should be installed wherever a combustion appliance is present and wherever occupants sleep. The following guidance is based on BS EN 50292 (the installation standard that accompanies EN 50291) and HSE recommendations:
- Every room with a fixed combustion appliance — gas or oil boiler, gas fire, wood-burning stove, open fireplace, log burner, or pellet stove. The alarm should be on the same level as the appliance, within 1–3 metres where possible.
- Each sleeping level of the home — CO is particularly dangerous at night when occupants cannot self-evacuate. An alarm in or adjacent to sleeping areas provides the earliest possible warning.
- Mounting height — CO has a similar density to air and disperses evenly. EN 50292 recommends mounting on a wall or ceiling. Wall mounting: between 1.5m and 2.1m above the floor. Ceiling mounting: as per manufacturer instructions (minimum 300mm from walls/corners).
- Avoid — direct sunlight, areas of high humidity (bathrooms, directly above cookers), areas with strong airflow (directly next to windows, fans or air conditioning vents), and garages or enclosed parking areas (vehicle exhaust will trigger the alarm).
Standalone vs Wireless Interconnected — Which Variant?
| Feature | DHI-HY-GC20D ★ (this product) Standalone |
DHI-HY-GC20D-R8 Wireless Interconnected |
|---|---|---|
| Wireless interconnection | ✗ No | ✓ Yes — up to 24 Wisulink devices |
| App / smart home integration | ✗ No | ✓ Optional — via DHI-HY-GW01A Gateway |
| Battery | 10-year sealed CR123A (non-replaceable) | 10-year sealed CR123A (non-replaceable) |
| LCD CO display | ✓ Yes | ✓ Yes |
| Alarm volume | >85dB @ 3m | >85dB @ 3m |
| EN 50291-1:2018 certified | ✓ Yes | ✓ Yes |
| Operating temperature | -10°C to +40°C | -10°C to +55°C |
| Best for | Single-room compliance, simple installs, rental properties, cost-effective standalone protection | Multi-room or whole-home coverage, properties where alarm in one room should sound all alarms, smart monitoring via app |
⚠️ Carbon monoxide — know the symptoms: CO is colourless and odourless — it cannot be detected by the senses alone. Symptoms of CO poisoning include headache, dizziness, nausea, breathlessness and confusion. If your CO alarm sounds: do not ignore it. Open windows and doors, evacuate immediately, do not re-enter until declared safe by the emergency services or gas-safe engineer. Call the Gas Emergency number: 0800 111 999.
Technical Specifications
| Specification | Detail |
|---|---|
| Product Identity | |
| Model number | DHI-HY-GC20D |
| Brand | Wisualarm (by Dahua) |
| Variant | Standalone (non-wireless) |
| Detection | |
| Sensor type | Electrochemical (Figaro) |
| Gas detected | Carbon monoxide (CO) |
| Sensor life | 10 years |
| Alarm Output | |
| Alarm volume | Over 85dB(A) at 3 metres |
| Alarm mode | Visual (LED) and audible |
| Silence function | Supported |
| Silence duration | Approximately 45 seconds |
| Display | LCD — live CO concentration (ppm) and peak-level memory |
| Power | |
| Power source | 3V CR123A lithium battery (non-replaceable, sealed) |
| Battery life | 10 years |
| Low battery warning | Yes |
| End-of-life warning | Yes |
| Environmental | |
| Usage environment | Indoor use only |
| Operating temperature | -10°C to +40°C (+14°F to +104°F) |
| Relative humidity | ≤95% RH (non-condensing) |
| Physical | |
| Dimensions (L × W × H) | 116.4 × 71.7 × 28.3mm (4.58" × 2.82" × 1.11") |
| Weight | 125g |
| Housing material | PC + ABS |
| Installation method | Wall mount |
| Certifications & Standards | |
| Standard compliance | EN 50291-1:2018 |
| Certifications | TÜV, CE |
| Wireless interconnection | Not supported (standalone only) |
FAQs
Does this alarm comply with the Smoke and Carbon Monoxide Alarm Regulations 2022?
Yes. The DHI-HY-GC20D is certified to EN 50291-1:2018, which is the standard specified in the statutory guidance accompanying the Smoke and Carbon Monoxide Alarm (Amendment) Regulations 2022 (England). It meets the technical requirements for a compliant CO alarm for private and social rented properties. The regulations require CO alarms in rooms with fixed combustion appliances (excluding gas cookers); this alarm is appropriate for those locations when used as a standalone unit. For properties requiring interconnected alarms across multiple rooms (e.g. to meet Scottish regulations under the Housing (Scotland) Act 2006), the wireless DHI-HY-GC20D-R8 variant should be considered.
Can the battery be replaced when it runs low?
No — the battery is permanently sealed within the unit and is not designed to be replaced. This is a deliberate safety feature: the sealed design ensures the alarm cannot be inadvertently disabled by battery removal, and the 10-year service life is matched to the sensor's operational lifespan. When the end-of-life warning sounds (typically after 10 years), the entire unit should be replaced. This is consistent with BS EN 50291 guidance on CO alarm replacement intervals.
What is the difference between this and the DHI-HY-GC20D-R8?
The DHI-HY-GC20D (this product) is a standalone alarm — it operates independently, with no wireless connectivity to other alarms. It is the simpler, lower-cost option for single-room CO protection or for properties where interconnection is not required. The DHI-HY-GC20D-R8 adds Wisulink RF wireless interconnection, allowing it to communicate with up to 24 other Wisualarm devices (smoke alarms, heat alarms, CO alarms) — when one triggers, all sound simultaneously. It can also be connected to the optional Wisualarm Gateway (DHI-HY-GW01A) for smartphone app alerts. Both share the same Figaro electrochemical sensor, LCD display and 10-year sealed battery.
My alarm is beeping briefly every minute — is this an emergency?
A single brief beep every 30–60 seconds typically indicates either a low battery warning or an end-of-life signal — not a CO alarm event. A CO alarm triggers a continuous or rapid pattern of beeps. Refer to the user manual for the specific beep pattern meanings for this model. If the rapid alarm pattern sounds, treat it as a CO emergency, evacuate, and call the gas emergency line (0800 111 999) — do not assume it is a false alarm without investigation by a qualified engineer.
