Frequently Asked Questions
Natural gas detection, alarm placement, testing and New York City compliance, answered plainly. If what you need is not here, the installation guide and the spec sheet go into far more detail, and you can always email us.
How many alarms do I need?
One or more alarms may be required in each dwelling unit. Every fuel-gas-burning appliance must be covered by an alarm installed in the same room and within the required placement distance. One alarm may cover multiple appliances only when a single compliant location serves all of them.
In practice: an apartment with a range in the kitchen and a gas dryer in a separate laundry room will normally need two alarms, because no single position sits in both rooms within 3 to 10 feet of both appliances. A studio with a range and a gas water heater in the same room can usually be covered by one. Count appliances and rooms, not units.
For household protection beyond the legal minimum, the manufacturer also recommends one inside each bedroom where the door is closed while sleeping, one centrally located outside each separate sleeping area, and one on each level of a multi-level home.
Will my carbon monoxide alarm detect a natural gas leak?
No. A carbon monoxide alarm detects carbon monoxide, which is a by-product of incomplete combustion. A natural gas alarm detects methane, which is the unburned fuel itself. They measure completely different things and neither one covers for the other. A home with gas appliances needs smoke, carbon monoxide and natural gas detection, and each of those is a separate device.
Why do I need a gas alarm if I can smell gas?
The smell in natural gas is an odorant called mercaptan, added because methane itself has no smell at all. It is a good warning system with real gaps. Odorant can fade in older pipework, a slow leak behind an appliance or inside a wall cavity can build for hours before anyone walks close enough to notice, a heavy cold or a blocked nose removes the warning entirely, and nobody smells anything while they are asleep. The CG-GD1 monitors continuously and alarms when methane at the sensor reaches the specified 10% LEL threshold, whether or not anyone notices an odor. It is still possible to smell gas before the alarm activates, and if you do, leave immediately and call 911 or your gas utility rather than waiting for the alarm.
What does 10% LEL mean?
LEL stands for lower explosive limit, the lowest concentration of gas in air at which the mixture can ignite. For methane that point is around 5 percent of the air by volume. The alarm sounds at 10 percent of that limit, which is roughly half a percent methane in air. In plain terms, it sounds long before the air in the room is capable of igniting. That margin is what gives you time to get everyone out.
Where exactly do I install it?
Methane is lighter than air, so it rises. Install the CG-GD1 on a wall in the same room as the gas appliance, 3 to 10 feet horizontally from the appliance, 6 to 12 inches below the ceiling, and at least 5 feet from a cooking appliance or cooktop hood. Every distance, plus a full list of places not to install it, is on our installation page.
Do I need an electrician or a permit?
Not for a qualifying battery-powered installation. Under New York City rule 1 RCNY 908-02(g), a line powered gas alarm has to be installed by a licensed electrical contractor and requires permits. In qualifying existing buildings, a battery powered alarm may be installed by the building owner, by maintenance personnel or by the occupant. The CG-GD1 runs on a built-in lithium battery, so there is no wiring, no plug and no permit, and it mounts with the supplied mounting hardware. Different power requirements may apply to buildings completed on or after January 1, 2027, so confirm before specifying for new occupancy.
How do I test it?
Press the TEST button on the front of the unit. All of the LEDs light, the green LED then flashes three times, and the red and yellow LEDs turn on and remain solid. That sequence means the alarm is working. Test it before and after mounting, then once a week afterwards, which is what the manual specifies. Never test it with a lighter, because lighters burn propane and the alarm does not respond to propane.
What do the beeps and the LED colors mean?
The green LED flashes when the TEST button is pressed, to confirm the alarm has power. A long beep sounding for 1 second and repeating on a 0.9 second cycle, with the red LED flashing every 2 seconds, means natural gas has been detected at 10% LEL, and you should evacuate. Yellow is a fault or battery signal: one flash and one beep every 60 seconds is low battery, two flashes and two beeps every 60 seconds is a fault, and three flashes and three beeps every 60 seconds means the alarm has reached the end of its service life and needs replacing. The full table is on the spec sheet.
Does the battery need replacing?
No. The lithium battery is built into the alarm and is never replaced. There is no battery door, no annual change and nothing to buy. The battery is designed to last approximately 10 years from the date of activation, and the alarm itself reaches the end of its service life approximately 10 years after the installation date, at which point the whole unit is replaced. Never attempt to remove the battery, including to silence an alarm, because doing so disables the device permanently.
What should I do if the alarm goes off?
Treat it as a real leak. Do not operate any switch, phone or doorbell inside the property, and do not light a flame of any kind. Open doors and windows on your way out if you can do it safely, shut off the gas at the meter only if the valve is safe to reach on your way past, get everyone out of the building, and call your gas utility or the emergency services from outside. Do not go back in until you are told it is safe. Once the gas clears, the alarm stops and the red LED stops flashing on its own.
Does it detect propane, LPG or carbon monoxide?
No. The CG-GD1 detects methane, which is natural gas, and nothing else. It does not detect propane, LPG, butane, carbon monoxide, smoke, fire or heat. If your appliances run on propane rather than piped natural gas, this is not the right alarm for you.
Does this satisfy NYC Local Law 157?
Local Law 157 requires a natural gas detecting device that is listed and labeled to UL 1484, or UL 2075 where applicable, and manufactured in accordance with NFPA 715-2023. The ChesGuard CG-GD1 is ETL Listed by Intertek and conforms to UL Standard 1484:6ED 2025-02-28 under control number 5017086, and the certificate is published in full on our certifications page. Compliance also depends on correct placement and on the owner meeting the record keeping duties, so read our Local Law 157 guide alongside the official NYC sources linked there. The Department of Buildings does not approve or endorse any manufacturer's product, so no alarm on the market is NYC approved. What the rule asks for is the listing standard, and we state and evidence ours.
What is the deadline for New York City buildings?
January 1, 2027. A conditional extension existed under Local Law 102 of 2025, tied to whether battery powered alarms were commercially available. The Department of Buildings has since confirmed publicly that battery powered natural gas alarms are available from multiple manufacturers, which closes that condition, and the current DOB service update confirms January 1, 2027. Owners should plan around it as a fixed date.
Can I mount it on a pipe instead of a wall?
Yes. The alarm can be secured to a gas pipe or a similar vertical run using cable ties, which are useful where drilling into masonry is impractical. Cable ties are not supplied in the box, so you will need your own. All of the placement rules still apply, so check the height and the distance from the appliance before you fix it in position.
How long does shipping take, and what does it cost?
Standard shipping is free on every order shipped within the United States, with no minimum order value. Orders are processed within 5 to 10 business days and you will receive tracking details by email once your parcel ships. Rates and estimated times for international destinations are shown at checkout.
What is your return policy?
You have 30 days from receiving your order to request a return. The item needs to be unused, in its original packaging, and you will need proof of purchase. Email support@chesguard.com to start a return and we will send instructions and a return label. If anything arrives damaged or incorrect, contact us straight away and we will make it right.
