If the oven smells like gas when preheating, several possible causes will need to be investigated. A gas smell during preheating could be caused by a dirty oven, a failing igniter, packaging materials being left in the oven, or blocked oven vents.
The strength and frequency of the gas smell can also relate to the adding of odorant to the gas or propane used with the oven. If there is a strong odor of sulfur or rotting eggs, you may have a serious gas leak, which requires evacuation and contacting the proper authorities.
Because natural gas in its natural state has no odor, odorant, an additive containing chemicals that produce the sulfur or rotting eggs-like smell that we associate with natural gas is added so that a gas leak can be detected.
The strength of the natural gas smell can fluctuate depending on how much of the additive has been added and how you get the natural gas for your oven. If you have gas or propane tanks, you are more likely to notice a strong gas odor when the tanks are running low. If natural gas is piped to your home, the strength of the odor will depend on when the odorant is added to the gas. People with natural gas piped to their homes will typically notice a strong gas odor more frequently than those with gas or propane tanks.
So, smelling some natural gas when you start your oven is perfectly normal, and if the strength of the smell fluctuates, this is also likely to be perfectly normal – it is simply the result of how much or when the odorant has been added to the gas or propane.
However, the gas odor should go away when the gas ignites. If you are noticing a strong and consistent sulfur or rotting eggs-like smell, you likely have a dangerous gas leak.
2. Gas Leak
If there is a strong and consistent rotting eggs or sulfur-like smell, you should take the following precautions. If you also hear a hissing sound, it confirms that there is a gas leak.
- Disconnect the power to the oven.
- Extinguish any open flames.
- Open as many windows or doors as possible to provide ventilation.
- Evacuate pets and people. Leave the home, then contact your gas provider or the relevant emergency services.
- Do not smoke or ignite a flame.
- Do not use any electrical appliances, as turning on an appliance can provide a spark that will ignite the gas. Even starting a car or using a phone can produce a fatal spark.
3. Gas connections leak
A gas leak and subsequent smell can be caused by damaged gas connections to the oven. If gas connections are not sturdy and tight, gas can leak out. Depending on the severity of the leak, the situation can usually be resolved by turning off the oven, ventilating the area, and contacting a trained professional to find and repair the connections. Do not use the oven while gas connections are leaking, and if unsure, always contact a trained professional.
4. Failing gas igniter
In most cases, if you are noticing a gas smell when there shouldn’t be one, it is caused by a failing igniter. If an igniter is failing, the gas valve may not receive enough current, which causes the igniter to open slowly and not release enough gas to ignite the flame in the first few seconds as it should. The gas may eventually ignite, but the failing igniter can make you wonder why you are smelling gas when you shouldn’t be.
Testing and replacing a gas igniter requires safety precautions and some technical knowledge, which is why it is best left to a trained professional. However, if you are confident in your DIY skills, the gas igniter can be checked and replaced by following the instructions below.
- Disconnect the power to the gas oven.
- Turn off the gas supply to the oven.
- Empty the oven, removing the oven racks and the oven bottom.
- Remove the heat shield or flame spreader at the bottom of the oven by unthreading the screws that secure it to the oven frame.
- Locate the igniter, which is attached to the burner tube.
- Locate the igniter’s wiring harness. Depending on the type of oven, you may need to remove the oven panel the igniter sits on or remove a rear or lower front panel to access the wiring harness.
- After you have accessed the wiring harness, disconnect it, and make sure the igniter can be removed without its wiring harness getting caught on something.
- Remove the screws that secure the igniter to the burner. Depending on the type of oven, you may need to remove the entire burner assembly (igniter and burner) if there is not enough room to fit a screwdriver to unthread the igniter screws.
Now that you have removed the igniter, check if it is dirty. If it is dirty, you may be able to clean it to solve the problem. However, it can be difficult to clean the igniter without damaging it, so it is best to get a trained technician to check it.
To determine if the igniter is defective, it will need to be tested with a multimeter for continuity. If the multimeter shows a reading between 0 and 1100 ohms of resistance, it is likely working correctly. If the multimeter does not get a reading (or a very minor detection), the igniter does not have continuity and will need to be replaced.
5. Packaging materials
If you have recently installed the oven, there may be packaging materials left in it that are heating up and burning when the oven’s preheating function is turned on. If this is the case, you should turn off the oven immediately. The packaging materials will need to be removed from the oven before attempting to use it again.
6. Dirty oven
Oven odors are often caused by a dirty oven. If you are not in the habit of regularly cleaning the oven and cleaning up spills before they bake on, the debris can burn or block the gas flow, which leads to unusual odors and oven problems. Make sure to follow the manufacturer’s instructions regarding which cleaning products to use when cleaning the oven.
7. Blocked vents
If an item, like a removable oven mat or food residue, is blocking the oven’s vents, it may be responsible for an unusual odor, possibly gas, coming from the oven. To resolve the issue, make sure there is nothing in the oven that may be blocking the oven’s vents or causing the unusual odor.