HOUSTON -

This is not the time of the year for your heater to break down, but it's happening all over Houston and as a result, furnace repair companies are busier than ever.

"If it stays cold like this, we'll stay constantly busy," said Aaron Childress, manager for Hallmark One Hour Air Conditioning and heating. "Houston is not used to this weather. Heaters aren't used to this weather either so they break down a lot more when it's this cold."

The One Hour repair guys have been working non-stop as the temperatures fall in Houston, doing repairs on some units while doing maintenance service on many others as nervous homeowners don't want to take any chances this winter.

Jerry Lowe has several units in his Memorial area home and says the key is to make sure the units not only keep his family warm but that they aren't dangerous.

"That's one of things that's important to look for," he said. "Natural gas leaks; and the second thing is that the combustion is going correctly and you're not introducing carbon monoxide into the house because both of them will kill you."

The One Hour techs were at the home for several hours making sure the wiring was good and the tubes and blowers were clean and recommend all homeowners they should have maintenance plans so that units are checked all year round and stops problems before they become dangerous.

Meanwhile, the temperatures has Houstonians stocking up to try to stay warm.

"(Looking for) an outdoor heater; the big ones," said shopper Dinora Martinez.

But Martinez, like many shoppers, are finding heating supply shelves empty.

"The difference is this year, we had a freeze come in early.  So we sold out of the pipe insulation. We have a lot of firewood and heaters that have been sold out," said Hazim Faiz, Meyerland Lowe's Manager.

Frost blankets, faucet protectors, insulation and space heaters -- all gone or almost gone. The store manager says Black Friday sales also had a hand in depleting shelves.

The heaters will be on for several more days as the temperatures on Saturday are not expected to get out of the 30s. Winter advisories are in place for several counties to our north and while Friday's rain is over, the wind chill factor will make it feel like freezing or colder.

Not much relief is in sight. The seven day forecast calls for temperatures to dip into the 20s early next week.