Shutting Down Your Furnace as Weather Warms Up

As the weather warms up, homeowners make preparations for the change of seasons. Make shutting down your heating system for the warmer months part of your spring cleaning routine.

What You Can Do Now

Replace or clean your furnace filters. This is simple maintenance you can do yourself, but it's important to know your filter type, location and replacement/cleaning interval, which vary among furnace models. Consult your manufacturer's specifications.

Scheduling a professional maintenance visit is also important, especially if you have an older furnace. Most modern furnaces have shut-off valves that engage when problems occur, but many older units lack this feature. End-of-season maintenance is an opportunity to locate tiny cracks in the combustion chamber, which can leak deadly carbon monoxide gas.

Repair or Replace?

If your gas furnace is old enough to have a pilot light instead of electronic ignition, it's burning fuel constantly. Harvey Sachs, senior fellow with the nonprofit American Council for an Energy-Efficient Economy in Washington, recommends replacing these older units. "You're just burning dollar bills," he said.

According to The NEED Project, gas furnaces made 20 years ago are only about 60 percent efficient; meaning only about 60 percent of the fuel they use is turned into heat. Today's high-efficiency furnaces are up to 98 percent efficient.

A furnace's efficiency is expressed in an AFUE rating, or Annual Fuel Utilization Efficiency. The Federal Trade Commission requires all new furnaces and boilers to display an AFUE rating to help consumers compare.

For a cool to cold climate, Sachs recommends buying a furnace with an AFUE rating of at least 90 percent. Anything less is a waste of money, he contends. If you buy a furnace with an AFUE rating higher than 90 percent, "you get some things that are nice but less essential," Sachs said.

One is a variable speed blower fan, which comes on more gradually than a typical furnace fan. It also adjusts to the conditions, saving money in electricity throughout the year.

Another is modulating combustion, which Sachs likens to a dimmer on a light. It allows the furnace to run at a lower capacity in milder weather.

What About Boilers?

The same basics of buying a furnace apply to a hot water or steam boiler -- find a contractor who's knowledgeable and trustworthy, and have that contractor analyze your home before you buy.

Most boilers are fueled by either natural gas or oil. There are differences in what you can expect from each in terms of efficiency and features.

Like furnaces, natural-gas boilers have increased in efficiency in the last few decades. Sachs recommends a condensing natural-gas boiler with an AFUE of at least 90 percent. It works in much the same way a condensing furnace does.

With any boiler, look for a control system that adjusts run times and operating temperature to the outside temperature, Sachs recommended. A boiler should ideally operate at the lowest temperature that will still keep the house comfortable, and a good adaptive control system will achieve that.

The advice about choosing a condensing unit doesn't apply to oil-fired boilers, however. Because of the chemical structure of oil, condensing the flue gases doesn't provide as much benefit as it does with natural gas, Sachs said. Additionally, oil boilers are prone to problems such as soot and corrosion at lower temperatures.

Safeguard your heating equipment with a protection plan. Browse our heating protection plans or call us at (855) 334-3577 for more information.