If you think you smell gas in your home right now, stop reading. Get everyone out, leave the door open behind you, and once you are outside and away from the house, call Xcel Energy's emergency line or 911 first, then call us at (720) 880-8064. A suspected natural gas leak is not a situation to investigate from inside, and it is not a DIY repair. The rest of this page is for the calmer version: you caught a faint odor near the stove, your gas bill jumped with no change in usage, or a flame is burning wrong, and you want to know what the real signs of a leak are and what to do about them. We will walk through each one, in plain terms, grounded in what actually fails on Front Range gas systems.
What does a gas leak smell like?
Natural gas is colorless and odorless on its own. The utility adds a chemical called mercaptan so you can smell it, and it smells like rotten eggs or sulfur. That is the number-one sign of a leak, and it is the one you should never talk yourself out of. If you catch that rotten-egg smell near a gas appliance, the meter, or anywhere along a gas line, treat it as real until proven otherwise.
A few honest caveats, because people search this exact question. A very faint, brief sulfur smell right when a burner lights can be normal combustion. A persistent rotten-egg smell that lingers, gets stronger, or shows up away from an appliance is not. And some people, especially with a reduced sense of smell, may not catch a small leak at all, which is why the other signs below matter.
The smell test is the fastest signal, but it is not the only one. A slow leak behind a stove or at a meter fitting can be too small to smell day to day and still show up on your bill or in how an appliance behaves.
Signs of a gas leak in your house beyond the smell
A gas leak announces itself in more than one way, and the signs stack. If you have two or more of these at once, raise your confidence and act sooner.
"Two signs at once, a faint rotten-egg smell and a gas bill that climbed for no reason, is a pattern we see on loose flex connectors behind ranges. It is quiet enough to miss and real enough to find."
None of these signs are a reason to open the appliance yourself. They are a reason to get the gas safely shut off and get a licensed tech out to find the source.
What to do if you smell gas: the order that matters
When you suspect a leak, the sequence protects you. Do these in order, and skip any step that would keep you inside longer than you need to be.
1. Do not create a spark. No light switches, no phone inside, no matches, no appliances, no garage door opener, no starting a car in an attached garage. A spark in a room with gas is the actual danger, not the gas sitting still. 2. Get everyone out. People and pets. Leave the door open behind you so the space can air out, and do not stop to hunt for the source. 3. Shut off the gas only if it is safe and obvious. If there is a clearly reachable appliance shutoff or the main gas valve at the meter and you can reach it without lingering, you can turn it off. If that means staying inside a space that smells strongly of gas, skip it and just leave. 4. Call from outside, utility and 911 first. Once you are away from the house, call Xcel Energy's emergency number or 911. They respond to active leaks and can shut the gas at the meter. This comes before any plumber. 5. Then call us at (720) 880-8064. Once the immediate danger is handled, we find the source and make the permitted repair. We quote a flat rate before we touch anything.
Deft Plumbing is licensed, bonded, and insured in Colorado. Gas work is one of the places that matters most, because detecting and repairing a gas leak is licensed, permitted work, not a Saturday project.
When this is NOT a call for us (yet)
We would rather be straight with you than scare up a service call. A few things people worry are leaks usually are not.
If the smell lingers, strengthens, spreads, or comes with any other sign on the list above, it is not in this category. When in doubt, you leave and call from outside. There is no prize for guessing wrong on gas.
How we find a gas leak (and why it is licensed work)
Finding a leak is not sniffing and guessing. When we get to a home with a suspected leak, we use electronic combustible gas detectors calibrated for natural gas, and we run a pressure-drop test on the line to confirm whether it is holding or losing pressure. That tells us there is a leak and roughly where, without tearing open walls on a hunch.
"We find the actual failure and repair or replace only what is failing. A single loose flex connector nut is a fix, not a reason to re-pipe the whole house."
On Denver Metro homes, the failure points are predictable, and knowing them is half the job:
Any repair or new gas run is permitted, pressure-tested, and inspected work. We pull the permit, run code-compliant black iron or CSST, pressure-test every joint, and bond every CSST line per Denver code before anything fires back up. That is covered in full on our licensed gas line repair and electronic leak detection across the Denver metro page. If you are in Adams County, we handle the same work through gas line repair and leak detection in Brighton, and on the Jefferson County side through gas leak detection in Arvada.
Suspect a leak and the immediate danger is handled, or want a line checked after you caught an odor? Call (720) 880-8064 and we will diagnose the actual fault before we quote. You know the cost before we pick up a wrench.
Frequently asked questions
What does a gas leak smell like?
Like rotten eggs or sulfur. Natural gas has no smell on its own, so the utility adds mercaptan, an odorant that smells unmistakably like rotten eggs, specifically so you can detect a leak. If you notice that smell near a gas appliance, the furnace, the water heater, or the meter, treat it as a possible leak. A strong or spreading odor means leave the house and call Xcel Energy or 911 from outside before you do anything else.
What should I do first if I think I smell gas in my house?
Do not flip any switch, use your phone inside, or light anything. Get everyone out of the house, leave the door open behind you, and once you are safely outside and away from the home, call Xcel Energy's emergency line or 911 first. They handle the active emergency and can shut the gas at the meter. After that, call a licensed plumber like us at (720) 880-8064 to find the source and make the permitted repair. Do not stay inside to investigate.
Can I find and fix a gas leak myself?
No. Detecting and repairing a gas leak is licensed, permitted work, and for good reason. Pinpointing a leak takes electronic combustible gas detectors and a pressure-drop test, and any repair has to be pressure-tested and inspected to code. A wrong guess or a joint that is not truly sealed is dangerous. The safe DIY step is recognizing the signs, getting out, and calling the utility or 911 for an active leak. We handle the rest, licensed, bonded, and insured, with the gas run permitted and pressure-tested before it fires back up.
Get a suspected gas leak handled the right way
Deft Plumbing is licensed, bonded, and insured in Colorado, and we serve the full Denver Metro along the Front Range, from Aurora and Lakewood to Arvada and Brighton. If you have an active gas smell right now, the first call is Xcel Energy or 911 from outside the house. Once that immediate danger is handled, or if you caught an odor and want a line checked, we find the source with electronic detection, repair only what is failing, and pressure-test and permit the work.
Call (720) 880-8064 or read how we handle licensed gas line repair and leak detection across the metro. We diagnose first and quote the total before we touch anything. No hourly surprises.