Boilers are essential for providing heat and hot water to many households during frigid winters. However, the high temperatures and pressure involved in boiler systems also come with potential risks if safety precautions are not followed. At Summit Heating & A/C, we want to ensure our customers in Denver, CO understand common boiler hazards and how to avoid them through proper maintenance and operation.

When operated correctly, boilers are perfectly safe. However, negligence and lack of awareness regarding boiler dangers lead to thousands of accidents each year. The inherent risks of unchecked boiler issues range from deadly carbon monoxide leaks to catastrophic explosions. Thankfully, with routine professional servicing and maintenance from licensed technicians like ours at Summit Heating & A/C, the vast majority of these accidents can be prevented. So, what exactly makes boilers potentially dangerous? Below, we cover some of the most common boiler hazards homeowners should understand.


One of the worst potential boiler accidents is an explosion. The high-temperature water and pressure inside a boiler can lead to an explosive failure if something goes wrong. Boiler explosions were more common with older steam boiler designs but can still happen today if safety valves fail or pressure isn’t properly regulated. The results of a boiler explosion can be devastating, causing severe injuries or major property damage.

Regular maintenance and inspections by qualified professionals can greatly reduce explosion risks by identifying and addressing corrosion, cracks, or other defects before they cause a catastrophic failure. Modern building codes also require new boilers to have emergency pressure relief valves that vent steam if pressures become dangerously high. Following proper operating procedures and never tampering with safety devices is also critical to avoiding explosions.

Carbon Monoxide Poisoning

Another very serious danger with boilers is carbon monoxide poisoning. That’s because any gas-burning boiler can leak carbon monoxide if not adjusted right or if parts are damaged. You can’t see or smell carbon monoxide, which makes it so hazardous. Just a small leak can fill your home with dangerous levels very quickly.

When you breathe in carbon monoxide, it replaces the oxygen in your blood and suffocates you from the inside. At high concentrations, it can make you dizzy and nauseous, knock you out, or even cause death. We all like to think it couldn’t happen to us, but carbon monoxide poisoning can get anyone. Kids, older folks, and even healthy adults can experience severe symptoms before they even know there’s a leak.

So don’t take any chances. Make sure your boiler technician checks for carbon monoxide leaks during annual tune-ups. Make sure you have detectors on every floor of the home, too. That way, if any carbon monoxide is released, you’ll know right away and can get out of the house before it’s too late.


The high-temperature water and steam created by a boiler system can lead to serious burn injuries. Hot water pipes and baseboard heating units connected to the boiler can reach scalding temperatures of over 140 degrees Fahrenheit. Direct contact with the boiler’s heat exchanger or internal piping can severely burn skin in seconds.

Insulating all exposed pipes can help prevent accidental burns. Checking that baseboard heaters are not too hot to the touch is also advised. Keeping children away from the boiler and monitoring the system for leaks is key. Water leaking from pipes or the boiler itself should never be approached without proper protective equipment.


Like any major appliance, boilers involve electricity and wiring that can pose electrocution risks if not properly installed and maintained. Faulty electrical components in the boiler can lead to shocks or shorts. Water leaking near electrical connections or splashing onto exposed wiring also presents electrocution hazards.

Having an electrician inspect the boiler’s wiring for any issues annually is recommended. All electrical repairs should be left to qualified professionals. The area around the boiler should be kept dry, and electrical components protected from contact with water. Proper grounding procedures must also be followed during installation and repairs.


Given the combination of gas, electricity, and high temperatures, boiler systems can also be potential fire hazards. Leaked fuel that ignites, faulty electrical components sparking flames, or a boiler overheating and catching fire are all possible. Improperly stored fuels like propane, gasoline, oil, or coal can further increase fire risks.

Aside from following all general fire safety practices, having chimneys and flues regularly cleaned and inspected for blockages is key. An HVAC technician should also annually check boiler components for issues that could cause overheating. Keeping the boiler area clear of debris and maintaining the system according to manufacturer guidelines will also help avoid fires.


Boilers that run on natural gas or propane can release carbon monoxide gas, as discussed above. But even boilers that don’t burn fossil fuels present asphyxiation dangers. Without proper ventilation, boiler rooms and some tightly sealed modern homes can run low on oxygen.

Inadequate air supply during boiler operation can also release nitrogen dioxide and other toxic fumes into the living space. Tight boiler rooms with gas appliances are especially prone to oxygen depletion and dangerous gas buildup.

Having an HVAC professional assess the boiler room and home ventilation is recommended. Annual inspections of gas appliances like boilers for proper combustion can also help avoid air quality issues. Keeping boiler room doors open, running fans, or opening windows while operating gas/oil boilers provides extra protection.

Water Leaks and Mold

Leaking boilers or related piping can release large amounts of hot water. This can lead to flooding damage and promote mold growth in the home. Even small leaks over time can undermine the boiler’s functionality and structural integrity.

Catching water leaks early and repairing damaged pipes, heat exchangers, pumps, valves, and fittings is key. Inspecting these components during annual servicing allows technicians to address minor problems before they become major. Keeping an eye out for pooling water around the boiler can also help detect leaks.

Equipment Failure

Like appliances, boilers have components that gradually degrade over time. Circulation pumps, ignition controllers, pressure valves, heat exchangers, and more can eventually fail. This can leave homeowners without hot water or heat, which is especially dangerous in freezing weather.

Replacing parts before they fail maintains the boiler’s functionality. Manufacturers provide recommendations on component lifespans and replacement schedules. Adhering to these guidelines keeps boilers operating reliably for decades. Annual professional servicing again allows technicians to evaluate components and suggest repairs as needed.

By understanding these common boiler risks, any homeowner can take proactive steps to ensure their system remains safe for their family and home. At Summit Heating & A/C, our licensed professionals have extensive training in identifying and resolving any boiler hazards using the latest methods and technology.

Schedule an Appointment With the Boiler Safety Experts

Don’t leave your home and family vulnerable to hidden boiler dangers or wait for an emergency to get your system inspected. You should schedule a maintenance visit with our certified boiler technicians. We’ll be happy to answer any questions and set up a maintenance plan tailored to your boiler.

In addition to boiler servicing, Summit Heating & A/C offers premier heating, air conditioning, and plumbing services to homeowners throughout Denver, CO. Our team of fully licensed and insured technicians undergo rigorous training and background checks. No matter what issue arises in your home’s systems, you can rely on prompt, honest, and professional service from our staff. Call Summit Heating & A/C today to experience firsthand why we’ve been the area’s most trusted HVAC and plumbing provider for over ten years.

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