3 Reasons Why A Ventless Gas Heater Would Smell

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Imagine you have guests at your place. You turned on your gas heater to warm up the house. The very next second, you all experienced a stinky odor. That must be an embarrassing situation for you. Okay, a bit dramatic, but this does happen, and there are many reasons why a ventless gas heater would smell when turned on. Below I’ll go over many reasons why this happens.

There can be three reasons why your ventless gas heater smells. Firstly, dust or other adulterated elements in the air can cause odor. Secondly, the smell can occur at the time of ignition. Thirdly, evaporated particles from spray paint or other substances that get stuck in the heater burn cause odor. 

However, there are ways to prevent your ventless gas heater smell. You will find a detailed discussion in the following parts. 

Why Does My Ventless Gas Heater Smell?

People who use a ventless gas heater often complain about the odd smell of the gas heater. In most cases, the reasons can be taken care of easily. 

ventless gas heater

Your ventless gas heater may smell like burning plastic, kerosene, or lighter fluid. Sometimes the house may smell like cotton candy as well. And the reasons may differ according to smell. 

The most common reasons a ventless gas heater would smell are:

  1. Dirt clog leads to impure air.
  2. Ignition issues that are sourced from pilot light issues or the presence of flammable materials.
  3. Evaporated Particles.

Below, find break-downs of each of these reasons followed by the solutions to these problems-

Reason 1: Impure Air (Improper Combustion)

Ventless gas heaters can’t take the air from outdoors for combustion. They take it from indoors. That depletes the levels of oxygen in the air inside your house. 

But that only can cause a health issue. Other than that, this won’t make your house smell bad.

But the combustion that happens inside the gas heater can stink your house. It’s because dirt and other impure particles in the house air go inside for combustion. There they get burned and generate a burning smell.

ventless gas heater smells

It may be uncleaned, pilled dust inside the heater as well, which causes the smell. This dusty air or heaters can be why your gas wall heater smells


The first solution to this issue is to dust off your heater more often. However, dusting off won’t clean the whole thing properly. 

In that case, you need to clean your ventless heater from head to toe. You can follow this ventless heater cleaning guide to clean your ventless heater.

The next tip is to vacuum your house to keep the air clean. If you don’t have a vacuum cleaner, I urge you to get one immediately. 

Vacuum CleanerSelling PointsPrice
Bissell Lightweight Bagless Vacuum With Crevice ToolFeatherweight, Stick Type, Bagless, and CheapestCheck Price on Amazon
PRETTYCARE Vacuum CleanerCordless and LightweightCheck Price on Amazon
BISSELL 2252 CleanView Swivel Upright Bagless VacuumSwivel Steering, Powerful Pet Hair Pick Up, Specialized Pet Tools, Large Capacity Dirt TankCheck Price on Amazon
Shark NV360 Navigator Lift-Away Deluxe Upright VacuumHEPA Filter, Swivel Steering, Upholstery Tool & Crevice Tool, and Average PriceCheck Price on Amazon
Quantum X Upright Water Filter VacuumWater & MicroSilver FiltrationCheck Price on Amazon

If you have pets, then having a vacuum cleaner is a must. Otherwise, the hairs of your pet might get into your heater and participate in combustion, which will spread a bad smell. 

Do not let your pets sit this close to the heater. It might cause them to harm, as their fur can fall into the heater and emit a bad smell.


Now, what if you’re a super clean person? It can’t be your reason, right? Then your house may smell due to an electric ignition or other.

Reason 2: Electric Ignition and Gas Pipe

The moment you turn on the electric igniter of the gas heater, a blue flame lights up. But you don’t notice that the mild smell comes at that moment. It stayed for the shortest possible time and disappeared. 

This smell can be strong sometimes if your furnace has any dirt or flammable objects. Also, if the furnace takes a long time to heat the house, the odor can get unbearable. Or an already smelly room can enhance the bad smell. 

Another thing to consider is the gas pipe. The pipe can be filthy inside. So, gas can also carry that filth when it comes out of the tube. Which further burned off in the gas burner and smelled like lighter fluid or so. 

Also, it could be the type of gas heater you have.

Two types of gas heaters on the market. The blue flame heaters smell slightly worse than infrared or radiant heaters.  

Unlike blue flame heaters, these don’t heat up the air. They warm up the object inside the house.

electric ventless gas heater


All you can do to solve this issue is to clean up your gas heater. Make sure the gas pipe is clean from the inside as well.

If you have a blue flame, you can try a radiant heater. This will not heat up the air of the entire house. It’ll just warm up the objects inside the house.

Reason 3: Evaporated Particles 

The evaporating particles like petroleum-based cleaner, paint, and varnish get into the air. Sometimes, these particles stick inside the radiator and get burnt. Eventually, this burnt smell spreads across the space when the heater is turned on.

If the radiator takes long enough to burn, the smell will intensify. This can cause a strong kerosene-like smell as well.

This smell can last for a few hours up to half of the day. 

So, have you used a gun cleaner or spray paint recently inside your house? If yes, then you know why your gas heater smells.


In the case of evaporated particles, no heater can guarantee it will stay smell less. 

All you can do is clean up the radiator inside and out. You need to turn the heater off and take out the radiation carefully. And use a soft, dry fabric to clean it properly.

portable heater

How Do I Prevent My Ventless Gas Heater Smell?

To make a ventless gas heater smell better, start by cleaning the appliance to remove any soot or debris build-up. Check for any leaks in the fuel line or fittings and replace if necessary. Make sure that your living space is well-ventilated to reduce the buildup of moisture and dust particles inside the heater’s chamber. Finally, use an air freshener or scented oils near the appliance to help mask any lingering odors.

Having said that you’ve fixed the smell problem of your gas heater; here are some tips to prevent it in the future:

Paint in a Garage

Take it to the garage if you have to paint your old furniture or varnish it. Avoid using such products inside your house or room. Thus the particles won’t get into your heater.

This creates a weird smell and is not good for your lungs. Even without a gas heater turned on, the smells can spread out in the room. 

Install a Room Air Purifier

Remember, we talked about dirt and dust in the air. An air purifier can help filter all the impurities. You can find an air purifier according to your need in the list below.

Air PurifierBudget CategoryPrice
AROEVE Air Purifiers for HomeBest ValueCheck Price
LEVOIT Air Purifier for HomeAffordableCheck Price
Shark HP102 Air PurifierExquisite OneCheck Price

I hope this will help you buy a good air purifier. The smell will go from mild to none if activated properly.

We tried our best to give you simpler reasoning. We all know science is difficult. That’s why we attempted to write in everyday language. This will surely help you identify the problem.

If, after doing all of these, the smell doesn’t go away, then you should consider replacing your gas heater with an electric heater because an electric heater might be the best possible way to heat your home.

Frequently Asked Questions (FAQs)

Why Propane Gas Heater Smells Like Kerosene?

In most cases, a gas heater smells like kerosene or as if it’s burning. When a gas heater smells like burning, it’s better to turn it off. Clean the inside of it and then start again to see if it still stinks.

Do Ventless Heaters Produce Carbon Monoxide?

Yes, a ventless heater can produce carbon monoxide if combustion is incomplete. It can only happen in a gas heater. Incomplete combustion can occur when there’s a lack of oxygen. Also, when the proportion of the mixing elements is not adequate. But be careful since it’s a toxic gas.

Is a Ventless Natural Gas Heater Safe?

Yes, ventless natural gas heaters are safe as long as it’s maintained properly. You’ve to make sure the heater gets enough oxygen for combustion.  To avoid odor, keep the heater clean. It becomes unsafe when they produce a good quantity of carbon monoxide. Also if there’s leakage in the gas pipe.

Can Gas Heaters Make You Sick?

Yes, a gas heater can make you sick only if it hasn’t been serviced yet. Servicing helps to clean the inside of the heater. Moreover, it gives you a green signal of how long you can keep it on. If you have a clean heater, there are fewer chances your house will smell foul. Thus you won’t feel sick.

Why would a ventless gas heater smell like burning plastic?

A ventless gas heater may smell like burning plastic due to a buildup of soot or other byproducts from incomplete combustion inside the appliance, which can cause an unpleasant odor when heated. It could also be caused by an electrical issue such as faulty wiring, which can create sparks and cause plastic components to melt or catch fire.

Why would a ventless gas heater smell like kerosene?

A ventless gas heater may smell like kerosene due to a buildup of unburned fuel inside the appliance, which can cause an unpleasant odor when heated. It could also be caused by a leak in the fuel line or fittings, which can allow liquid fuel to escape into your living space and create an unpleasant smell.

Summing Up

This article has undoubtedly clarified your queries about why my ventless gas heater smell. Now you know the reason, still consult an expert before making the decision. 

We’re highly suggesting you for doing a gas heater check-up. In case you haven’t done one in recent times. 

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