The Smart Device Compare comparison

Heiman WS2CG Series Combustible Gas Detector vs Shelly GAS (CNG)

Understand the differences. Decide what matters to your home.

Before you compare every specification

Key differences between Heiman WS2CG Series Combustible Gas Detector and Shelly GAS (CNG)

A summary of selected recorded differences between these gas detectors. Check the full specification table below for details and conditions.

Feature differences among your selected devices

Voice Alerts (alerts): Heiman WS2CG Series Combustible Gas Detector — Yes (Audio and flash alarm plus a spoken voice prompt); Shelly GAS (CNG) — No.
Lpg Propane (detection): Heiman WS2CG Series Combustible Gas Detector — Yes (Heiman lists natural gas and LPG as the detected gases); Shelly GAS (CNG) — No (Shelly sells a separate LPG version for propane and butane).
Alexa (integrations): Heiman WS2CG Series Combustible Gas Detector — No (Neither the Alexa smart home API nor the Google Home SensorState trait defines a combustible gas sensor type, so the alarm cannot be exposed to it); Shelly GAS (CNG) — Yes.
Google Home (integrations): Heiman WS2CG Series Combustible Gas Detector — No (Neither the Alexa smart home API nor the Google Home SensorState trait defines a combustible gas sensor type, so the alarm cannot be exposed to it); Shelly GAS (CNG) — Yes.

Information still to confirm

9 of 37 comparison fields lack a resolved value for at least one selected device. Missing information is not evidence that a feature is absent.
Check the full table and manufacturer documentation before ruling out a device.

These observations are derived from recorded catalog data and have not all been independently verified. Confirm details with the manufacturer before purchasing.

Compare capabilities, compatibility and setup requirements.

Option 1 · Heiman

Heiman WS2CG Series Combustible Gas Detector

Catalog update date not recorded

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Option 2 · Shelly

Shelly GAS (CNG)

Catalog update date not recorded

View full device profile

What the catalog tells us

Understand the tradeoffs.

These counts describe the available data, not a quality score. More features do not automatically make a better device.

5differences with recorded values for every device

9rows with missing or unspecified information

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Focus on what changes.

Mark the specifications you care about. Open manufacturer sources for verification scope; fields without citations remain catalog data. Expand notes for other qualifications.

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Showing 37 of 37 rows. “Not recorded” does not mean “No”.

Reading layout

Alerts

Alarm Volume

Heiman WS2CG Series Combustible Gas Detector: 70 dB
Shelly GAS (CNG): 70 dB

App Notifications

Heiman WS2CG Series Combustible Gas Detector: Yes
Catalog note
Real-time notifications through the Tuya Smart Life app
Shelly GAS (CNG): Yes

Fault Alerts

Heiman WS2CG Series Combustible Gas Detector: Yes
Catalog note
Yellow LED flashes with a voice prompt when the unit faults
Shelly GAS (CNG): Yes
Catalog note
The sensor state is reported as warmup, normal, fault or unknown

Low Battery Alerts

Heiman WS2CG Series Combustible Gas Detector: Not applicable / unspecified
Shelly GAS (CNG): Not applicable / unspecified

Voice Alerts

Heiman WS2CG Series Combustible Gas Detector: Yes
Catalog note
Audio and flash alarm plus a spoken voice prompt
Shelly GAS (CNG): No

Connectivity

2.4 GHz Wi-Fi

Heiman WS2CG Series Combustible Gas Detector: Yes
Catalog note
Connects straight to WiFi and the Tuya Smart Life app, no hub required
Shelly GAS (CNG): Yes
Catalog note
802.11 b/g/n, 2400-2484 MHz, no hub required

5 GHz Wi-Fi

Heiman WS2CG Series Combustible Gas Detector: No
Shelly GAS (CNG): No

Bluetooth

Heiman WS2CG Series Combustible Gas Detector: No
Shelly GAS (CNG): No

Other

Heiman WS2CG Series Combustible Gas Detector: No
Shelly GAS (CNG): No

Thread

Heiman WS2CG Series Combustible Gas Detector: No
Shelly GAS (CNG): No

Z Wave

Heiman WS2CG Series Combustible Gas Detector: No
Shelly GAS (CNG): No

Zigbee

Heiman WS2CG Series Combustible Gas Detector: No
Shelly GAS (CNG): No

Detection

Alarm Threshold

Heiman WS2CG Series Combustible Gas Detector: 6% LEL
Shelly GAS (CNG): 6% LEL

Carbon Monoxide

Heiman WS2CG Series Combustible Gas Detector: No
Shelly GAS (CNG): No

Concentration Reading

Heiman WS2CG Series Combustible Gas Detector: Not recorded
Shelly GAS (CNG): Yes
Catalog note
The device reports the measured concentration in ppm through the app and the local API

Lpg Propane

Heiman WS2CG Series Combustible Gas Detector: Yes
Catalog note
Heiman lists natural gas and LPG as the detected gases
Shelly GAS (CNG): No
Catalog note
Shelly sells a separate LPG version for propane and butane

Natural Gas

Heiman WS2CG Series Combustible Gas Detector

Yes

Manufacturer source

The stated target gas is methane in natural gas.

Heiman WS2CG Series Combustible Gas Detector manufacturer product page →

Source section: Product description
Model: Heiman WS2CG Series Combustible Gas Detector
Region: Manufacturer product page; no universal regional compatibility implied
Firmware: Not specified by this source
Checked: 2026-10-04

This statement does not establish LPG detection or certification for a particular jurisdiction.

Document check only; not a hands-on test or verification of every regional or firmware variant.

Shelly GAS (CNG)

Yes

Catalog note

Calibrated for compressed natural gas (methane)

Sensor Life

Heiman WS2CG Series Combustible Gas Detector: Not recorded
Shelly GAS (CNG): Not recorded

Sensor Type

Heiman WS2CG Series Combustible Gas Detector: Semiconductor
Shelly GAS (CNG): Not recorded

Features

Automations

Heiman WS2CG Series Combustible Gas Detector: Yes
Shelly GAS (CNG): Yes
Catalog note
Scenes can react to the alarm and drive any other Shelly device

Certification

Heiman WS2CG Series Combustible Gas Detector: Not recorded
Shelly GAS (CNG): Not recorded

Digital Display

Heiman WS2CG Series Combustible Gas Detector: No
Shelly GAS (CNG): No

History Records

Heiman WS2CG Series Combustible Gas Detector: Not recorded
Shelly GAS (CNG): Not recorded

Interconnect

Heiman WS2CG Series Combustible Gas Detector: No
Shelly GAS (CNG): No

Mute Silence

Heiman WS2CG Series Combustible Gas Detector: Not recorded
Shelly GAS (CNG): Yes
Catalog note
Mute and unmute the sounder remotely

Self Test

Heiman WS2CG Series Combustible Gas Detector: Yes
Catalog note
Push-to-test button on the front of the unit
Shelly GAS (CNG): Yes
Catalog note
Self-test can be triggered from the app or the local API

Valve Shut Off

Heiman WS2CG Series Combustible Gas Detector: Yes
Catalog note
Drives a valve manipulator accessory that closes the gas valve on alarm
Shelly GAS (CNG): Yes
Catalog note
11-13V 500mA jack output drives the Shelly Gas Add-on valve manipulator, which is sold separately

Integrations

Alexa

Heiman WS2CG Series Combustible Gas Detector: No
Catalog note
Neither the Alexa smart home API nor the Google Home SensorState trait defines a combustible gas sensor type, so the alarm cannot be exposed to it
Shelly GAS (CNG): Yes

Apple Home

Heiman WS2CG Series Combustible Gas Detector: No
Shelly GAS (CNG): No

Google Home

Heiman WS2CG Series Combustible Gas Detector: No
Catalog note
Neither the Alexa smart home API nor the Google Home SensorState trait defines a combustible gas sensor type, so the alarm cannot be exposed to it
Shelly GAS (CNG): Yes

Home Assistant

Heiman WS2CG Series Combustible Gas Detector: Yes
Catalog note
Tuya device, covered by the gas alarm category of the official Home Assistant Tuya integration
Shelly GAS (CNG): Yes
Catalog note
Local control over the HTTP, MQTT and CoAP APIs

Matter

Heiman WS2CG Series Combustible Gas Detector: No
Shelly GAS (CNG): No

SmartThings

Heiman WS2CG Series Combustible Gas Detector: No
Shelly GAS (CNG): Yes

Power

Battery Backup

Heiman WS2CG Series Combustible Gas Detector: No
Shelly GAS (CNG): No

Battery Life

Heiman WS2CG Series Combustible Gas Detector: Not applicable / unspecified
Shelly GAS (CNG): Not applicable / unspecified

Battery Type

Heiman WS2CG Series Combustible Gas Detector: Not applicable / unspecified
Shelly GAS (CNG): Not applicable / unspecified

Wired

Heiman WS2CG Series Combustible Gas Detector: Yes
Catalog note
Mains powered, AC 100V-240V
Shelly GAS (CNG): Yes
Catalog note
Plugs straight into a socket, 110-230V AC 50/60Hz, under 3 W

Specifications for Heiman WS2CG Series Combustible Gas Detector versus Shelly GAS (CNG)
Specification	Heiman WS2CG Series Combustible Gas Detector	Shelly GAS (CNG)
Alerts
Alarm Volume	70 dB	70 dB
App Notifications	Yes Catalog note Real-time notifications through the Tuya Smart Life app	Yes
Fault Alerts	Yes Catalog note Yellow LED flashes with a voice prompt when the unit faults	Yes Catalog note The sensor state is reported as warmup, normal, fault or unknown
Low Battery Alerts	Not applicable / unspecified	Not applicable / unspecified
Voice Alerts	Yes Catalog note Audio and flash alarm plus a spoken voice prompt	No
Connectivity
2.4 GHz Wi-Fi	Yes Catalog note Connects straight to WiFi and the Tuya Smart Life app, no hub required	Yes Catalog note 802.11 b/g/n, 2400-2484 MHz, no hub required
5 GHz Wi-Fi	No	No
Bluetooth	No	No
Other	No	No
Thread	No	No
Z Wave	No	No
Zigbee	No	No
Detection
Alarm Threshold	6% LEL	6% LEL
Carbon Monoxide	No	No
Concentration Reading	Not recorded	Yes Catalog note The device reports the measured concentration in ppm through the app and the local API
Lpg Propane	Yes Catalog note Heiman lists natural gas and LPG as the detected gases	No Catalog note Shelly sells a separate LPG version for propane and butane
Natural Gas	Yes Manufacturer source The stated target gas is methane in natural gas. Heiman WS2CG Series Combustible Gas Detector manufacturer product page → Source section Product description Model Heiman WS2CG Series Combustible Gas Detector Region Manufacturer product page; no universal regional compatibility implied Firmware Not specified by this source Checked 2026-10-04 This statement does not establish LPG detection or certification for a particular jurisdiction. Document check only; not a hands-on test or verification of every regional or firmware variant.	Yes Catalog note Calibrated for compressed natural gas (methane)
Sensor Life	Not recorded	Not recorded
Sensor Type	Semiconductor	Not recorded
Features
Automations	Yes	Yes Catalog note Scenes can react to the alarm and drive any other Shelly device
Certification	Not recorded	Not recorded
Digital Display	No	No
History Records	Not recorded	Not recorded
Interconnect	No	No
Mute Silence	Not recorded	Yes Catalog note Mute and unmute the sounder remotely
Self Test	Yes Catalog note Push-to-test button on the front of the unit	Yes Catalog note Self-test can be triggered from the app or the local API
Valve Shut Off	Yes Catalog note Drives a valve manipulator accessory that closes the gas valve on alarm	Yes Catalog note 11-13V 500mA jack output drives the Shelly Gas Add-on valve manipulator, which is sold separately
Integrations
Alexa	No Catalog note Neither the Alexa smart home API nor the Google Home SensorState trait defines a combustible gas sensor type, so the alarm cannot be exposed to it	Yes
Apple Home	No	No
Google Home	No Catalog note Neither the Alexa smart home API nor the Google Home SensorState trait defines a combustible gas sensor type, so the alarm cannot be exposed to it	Yes
Home Assistant	Yes Catalog note Tuya device, covered by the gas alarm category of the official Home Assistant Tuya integration	Yes Catalog note Local control over the HTTP, MQTT and CoAP APIs
Matter	No	No
SmartThings	No	Yes
Power
Battery Backup	No	No
Battery Life	Not applicable / unspecified	Not applicable / unspecified
Battery Type	Not applicable / unspecified	Not applicable / unspecified
Wired	Yes Catalog note Mains powered, AC 100V-240V	Yes Catalog note Plugs straight into a socket, 110-230V AC 50/60Hz, under 3 W

Know what’s behind the comparison.

The table matches specifications by section and field. It preserves notes, separates missing data from explicit “No” values, and keeps qualifications attached to their values. No overall winner is assigned from feature counts.

Read our comparison methodology