Why HVAC Combustion Testing Is Important

Most American homes generate their heat from gas-powered furnaces or boilers. These forced-air units warm air by igniting a fueling source like heating oil, propane, or natural gas. Ducts then distribute the hot air throughout a home or building.

By burning a fueling source, gas furnaces and boilers emit varying levels of excess air and exhaust. The furnace gas valve works to release these carbon gases, which then run through a flue that extends to the exterior.

A properly running heating system will have a healthy fuel-to-air ratio. Too much fuel or too much air getting into the combustion chamber can cause dangerous fluctuations in exhaust levels. This can result in the unnecessary overproduction of carbon emissions.

Carbon monoxide and carbon dioxide, in excess, cause harmful effects on both people and the environment. Carbon monoxide poisoning is a real threat in homes heated by gas furnaces. Symptoms like headache, dizziness, and fatigue are signs of carbon monoxide poisoning. Severe cases can result in irreversible long-term effects like brain damage, heart problems, and memory loss.

The safety risks that natural gas leaks and high carbon monoxide (CO) levels cause often go under the radar. Things like a faulty gas valve, cracks in the flue, and blockages in the flow of gas can all contribute to high CO. You can prevent excessive carbon emissions leaking into your home by doing a combustion test on your furnace.

HVAC combustion analyzers test the heat exchanger in a home’s furnace or boiler. The main purpose of a combustion test is to measure the levels of oxygen, carbon dioxide, and carbon monoxide. It also measures variables such as flue and stack temperature, draft pressure, and combustion byproducts. Combustion analyzer readings calculate the emission levels and efficiency of a heating system.

HVAC technicians will typically do visual inspections for gas leaks, but thorough combustion tests are not mandated. Professionals highly recommend having a combustion test done annually. Combustion gas analyzer technology covers the hairline cracks and hidden leaks that contractors may miss.

Homeowners often overlook the many benefits of combustion testing. Because it is not a regulated practice, combustion testing rarely happens after the first installation.

The first and most important benefit of combustion testing is preventing the danger of carbon monoxide poisoning. Reducing carbon emissions out of your home also mitigates air pollution and benefits the environment.

When a furnace is producing too much carbon monoxide, it is wasting fuel and the power used to ignite it. This results in heat losses and spikes in energy costs that are preventable.

Combustion analysis identifies leaks or areas where carbon gases are emitting at dangerously high levels. Repairing these problem areas with a maintenance tune-up increases the efficiency of your heating system. High combustion efficiency has the power to cut your utility bills and increase your home’s value.

Every gas heater is different, meaning they require different methods of combustion testing for the most accurate readings. Professional technicians have the best combustion analyzers, but you can also buy an individual combustion detector yourself. Doing a combustion test yourself is possible with the right equipment, but hiring an HVAC professional produces the best results.

Standard exhaust gas tests work by inserting a combustion analyzer into the flue pipe of the heating system. For high efficiency heaters that use plastic pipes for ventilation, it is best to test the flue gases on the exterior of the house. Some furnaces also have built-in test ports for the explicit purpose of combustion testing. Rather than drilling into the flue or stack, it is more efficient to test from an access point.

Ideally, the level of ambient carbon monoxide should be 0 parts per million, or 0PPM. Anything above that is a sign of an improperly functioning heating system. Studies show that levels of 5PPM and above are harmful to the average human.

HVAC professionals recommend that you test your flue gas at least once a year. Combustion can adjust over time with seasonal and weather changes, causing spikes or reductions in gas usage and emissions.

You can also invest in carbon monoxide monitors for year-round analysis. These devices notify whenever levels surpass 5 parts per million.

Overall, it is worth the investment to do some kind of combustion testing in your home to reduce safety risks. Carbon monoxide is an unfortunate byproduct of fuel-powered heating, but it is preventable with readily available technology.