Furnace repair businesses hopping as cold spell hits SE Wis.

MILWAUKEE (WITI) -- One of the businesses that's hoping during this bitter cold spell is furnace repair businesses.

Kettle Moraine Heating and Air Conditioning has been bustling with service calls all weekend.

In some cases, people need a new furnace, but often, it's problems associated with maintenance -- such as a clogged filter, a dead thermostat battery or snow piles that are blocking the PVC exhaust pipes.

The biggest advice is to call for service early.

"If you start to see things that are hiccupping or having problems early in the week or early in the day -- call us then.  We get so many people who call us between 3-5 o'clock on Friday night, and then of course the charges are higher because it's after hours," Bill Brink said.

Furnace repair companies all offer 24-hour emergency service, but it will cost you more when it's overnight or on the weekend.

You can find a reputable company by checking with Milwaukee NARI.