Can a furnace explode?

Yes, furnaces can explode. The natural gas that serves furnaces is flammable. However home explosions sparked by a furnace are very rare. Modern furnaces have safety features built in to shut off when something goes amiss.

After 5 or more years of use, weaknesses in your furnace can develop.

In winter, especially at startup, is when most furnace explosion occur due to the lighting up of a boiler burner and winter is a time of increased furnace load.

That’s when weaknesses in your homes central heating system are put to the test.

How can a furnace explode?

Your furnace burns fuel to produce heat, they release carbon monoxide.

While a properly maintained furnaces will release carbon monoxide gas through vents, an aging, or poorly serviced furnace can have leak through which carbon monoxide escapes.

This is what happened to one family in Cambridge, Minnesota, after their house exploded on furnace start up.

Furnaces have an ignition source, being the pilot light.

That means any accumulation of any flammable gas puts your furnace and home at risk of explosion.

How dangerous are furnace explosions?

Any gas powered furnace related explosions can be fatal.

A natural gas related explosion in Scarborough, Ontario, not only leveled the house, but left 1 dead, and another injured.

Gas furnace explosions can be so powerful, neighboring properties will be hit by debris, or receive structural damage themselves from the explosion shock wave.

Warning signs that your gas furnace can explode.

Improper furnace installations

Improper furnace installations are leading cause of furnace explosions.

In fact, the dangers associated with improper furnace installations are why in most jurisdictions it is illegal for anyone without a license to attempt to repair or install an appliance connected to a gas main.

Joints can not be sealed properly. Pressure valves can malfunction and that can allow too much pressure to rupture a line. This is often a problem with flexible gas lines. Any botched furnace repair or installation job can mean toxic gases entering the house and a risk of combustion.

Fuel or gas smell

If you are noticing any fuel smell, odor, or egg smell from your furnace or boiler room it can be serious issue. You should immediately evacuate the home or building. Following evacuation, have a certified HVAC technician out to inspect your central heating systems and gas connections. This is not a job you should be attempting to DIY fix yourself!

The flame of the burner is yellow rather than blue

Your furnace could leak carbon monoxide if it has a yellow burner flame(also called pilot light) instead of a blue one.

The invisibility, odorless-ness, and flammability of carbon monoxide makes it a very dangerous gas.

If your chimney does not have a draft upward, carbon monoxide particles may accumulate around your furnace.

If you suspect carbon monoxide leaks, shut off the gas, get everyone outside, and contact a professional furnace technician or licensed gas fitter immediately.

Your furnace is old

Many old furnaces run on oil or gas.

While many new furnaces do as well, comparatively, new furnaces have more advanced safety features such as: flame rollout sensors, flame proving sensors, high temperature limit control, flue exhaust pressure sensors, and fan limit sensors.

Without proper ventilation, old furnaces are a fire hazard.

Old furnaces can also develop cracks, leaking gas into the air, allowing carbon monoxide into the house instead of air.

It is also wise to keep any flammable materials away from your old furnace as this increase the chance of a fire, and subsequent furnace explosion.

Digging in the local area

When furnace-related explosions do happen, it’s usually because someone is digging on land nearby and cuts a gas line.

Any contractor digging in the area needs to have municipal approval to do so.

Gas powered furnaces, in combination with gas leaks from external underground sources, can be a dangerous combination.

The furnace is the ignition source in these cases.

Constantly having to adjust the thermostat

If you are not getting the heat our of your furnace you desire this could be simple fix or thermostat adjustment. However, it could also pose more serious concerned that should be investigated by a licensed furnace technician.

Poor efficiency or operation

Get your furnace inspected if it is struggling to maintain the temperature in your home or resulting in hiked up energy or gas costs.

A poorly operation or inefficient furnace is a tell tale sign that some components in your furnace may need replacement.

Any component on a furnace, whether it be related to the basic function or a safety feature, is incredibly important to have inspected for it’s operation.

Ideally, you will want to have your furnace inspected prior to start up in the winter.

How can you prevent furnace explosions?

Now if you’ve been asking yourself, “can a furnace explode”, it is clear the answer is yes.

Here are some simple tips for furnace explosion prevention:

• Replace furnaces over 10 years in age.
• Keep up with regular furnace service.
• Check gas connections, fittings, lines, and exhaust ducts.
• Call the local gas company about underground lines if you are digging in the area.
• Only trust the services of a licensed gas fitting expert.
• Do not perform DIY repairs on a furnace.
• Keep your CO(carbon monoxide) detector powered and operational.

Overall, if you’re not comfortable assessing the health of your furnace, call a professional.

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