FURNACE MAINTENANCE IMPORTANT

Calls increased somewhat last week for businesses handling furnaces as winter temperatures finally arrived.

The most common complaint found by two area heating contractors was clogged filters.

"People should check their filters regularly," said Jeff Kemp, an estimator with Halbert & Cook Inc. of Cape Girardeau.

His company answered several calls last week when customers said their furnaces weren't heating. The solution, in most cases, was filters so dirty air couldn't circulate through them.

Service calls picked up a little with the colder weather, said John Heise, owner of Heise Heating & Cooling Inc. of rural Cape Girardeau.

The faulty things his service people found included gas valves, safety limit switches and fan motors -- mostly from clogged filters that cause the furnace to run more than necessary.

Both men said the major item that can go wrong in a furnace is the heat exchanger, the area in a furnace where combustion takes place and the heat is transferred to the air that circulates in the house. A broken heat exchanger usually means buying a replacement furnace because the cost to replace one can be as high as an entire new unit.

Kemp said when a homeowner has had a gas furnace for about 15 years, it's usually time to expect some problems. He encourages his customers to have their heat exchangers checked every fall because a crack can lead to a carbon monoxide buildup in a house.

The latest information about modern gas furnaces relates to higher efficiency ratings for new units, the men said. The government now requires a rating of 78 percent for new furnaces, meaning only 22 percent of the energy is lost through the vents.

Customers can now buy furnaces with efficiency ratings around 95 percent. In these condensing furnaces, so little of the heat is lost that PVC pipes can be used for the exhaust vents while water is a byproduct that must be drained away.

Fitting the efficiency rating to the type of heating job required is an important decision in buying a new furnace, the men said. Since higher efficiencies mean more initial costs, the size of a house and the energy to heat that square footage have to be balanced with the furnace's cost for a consumer to receive the best value for his heating dollar.