Warning signs

A room that is a little cold is a comfort problem. A sign that fuel is not burning or venting properly is a safety problem. The CPSC lists signs that can point to an appliance not working properly: less hot water than usual, a furnace that cannot heat the house or runs all the time, soot (especially on appliances and vents), an unfamiliar or burning smell, and more moisture on the inside of windows. Some of these look like ordinary comfort problems, which is why they are easy to miss.

Behind several of these signs is a burner that is not working right. A dirty burner or a cracked heat exchanger causes improper burner operation, and either can make the equipment less safe and less efficient. Even new furnaces need upkeep, because they can also corrode and leak combustion gases, including carbon monoxide.

Source: U.S. Consumer Product Safety Commission · ENERGY STAR · U.S. EPA

The flame tells you something about how gas is burning. A persistent yellow-tipped flame generally means the burner is out of adjustment and is giving off more pollutants. A gas utility's appliance safety list also names gas flames that are pale yellow or wavy as a warning sign. Discoloration at the appliance's burner, burner door or vent area is another.

Soot is a sign worth acting on. Sooting, especially on appliances and vents, can point to improper appliance operation. Soot on a water heater tank, together with melted plastic washers on its pipes, shows that it has backdrafted and may still be doing so. The CPSC says a chimney sweep should be called if the fall inspection finds soot on the chimney walls.

Source: U.S. EPA · Nicor Gas · U.S. Consumer Product Safety Commission · U.S. Department of Energy

Your nose can warn you about some problems but not others. Gas utilities add an odorant to natural gas so it smells like rotten eggs and a leak is easy to notice. An unfamiliar or burning smell can also point to an appliance that is not working properly. Carbon monoxide, on the other hand, has no smell or color, so people may not know they are being exposed.

Your body can be the warning instead. Carbon monoxide poisoning symptoms are sometimes confused with the flu or food poisoning. They include dizziness, tiredness, headaches, nausea, vomiting and confusion. If anyone at home feels this way, use the safety steps at the end of this page.

Source: Peoples Gas · U.S. Consumer Product Safety Commission · U.S. EPA

The heat exchanger is the metal wall between the flame and the air your furnace blows. Combustion gases and particles can come from cracked furnace heat exchangers, as well as from chimneys and flues that are improperly installed or maintained. A crack is usually not something you can see yourself, which is why technicians test for it.

Technicians follow set steps. They inspect the visible parts of the combustion chamber for cracks, holes and corrosion and test the heat exchanger for leaks. A flame that is disturbed before or after the blower comes on may mean the heat exchanger leaks. If cracks or holes are found, federal guidance says to replace the heat exchanger if one can be found, or refer the unit for replacement.

Source: U.S. EPA · U.S. Department of Energy

Heating and cooling equipment runs on electricity, and electrical faults are a safety issue. Telltale signs of electrical problems include lights dimming and circuit breakers tripping or fuses blowing often. Faulty electrical connections can make your system run unsafely and shorten the life of major parts. The Electrical Safety Foundation recommends always using a qualified, licensed electrician for electrical work in your home, including installing and servicing cooling equipment.

Inside the equipment, stored energy is a danger. During servicing and maintenance, an unexpected start-up or release of stored energy can cause serious injury or death. Injuries from uncontrolled energy include electrocution and burns. That is why opening the cabinet and working on wiring is a job for a trained technician.

Water and gas equipment do not mix either. Natural gas furnaces, water heaters and dryers that have been in floodwater should be inspected by a contractor. If you see water around your equipment, say so when you ask for a check.

Source: U.S. Consumer Product Safety Commission · ENERGY STAR · Electrical Safety Foundation International · OSHA · Peoples Gas

Some signs mean the equipment should not keep running until it is checked. Do not run the heating and cooling system if you know or suspect it has mold in it, because it could spread mold through the building. If a furnace's carbon monoxide levels cannot be brought down to acceptable levels, federal guidance says to refer it for replacement as a health and safety measure.

The best way to catch problems early is a yearly check. Have your heating system, water heater and other fuel-burning appliances serviced by a qualified technician every year. Have furnaces, flues and chimneys inspected every year and properly repair cracks or damaged parts. If you notice any of these signs, tell us what you see and hear.

Source: U.S. EPA · U.S. Department of Energy · CDC