HVAC crews in Connecticut say they are seeing an increase in emergency service calls for failing home heating systems during the frigid temperatures.

Greg Barnum is an HVAC installer for Mobilio and Sons Heating and Cooling. Mobilio services Fairfield, Litchfield and New Haven counties.

He says it can be a nightmare situation to be left without heat during cold temperatures.

Bridgeport Fire Chief Lance Edwards says heating your home with your stove is one of the most dangerous things you can do, because of the risk of carbon monoxide poisoning.

Tanya Daniels says she has no choice but to heat her home that way. Daniels says the furnace in the apartment she rents on Center Street in the Hollow has been broken for weeks, forcing her to use the stove as a source of heat. She says the space heaters she has simply aren't powerful enough to do the job on their own.

"No one should wake up in their home and be cold. It's not fair," Daniels said.

Barnum says his crews have been working nonstop around the clock to meet demand.

"If you don't have good insulation in your house, if you don't keep the heat on too high, there's so many things that happens - and frozen pipes," said Barnum.

He is urging people, even renters, to know where the main water shut-off valve is, which he says can help prevent thousands of dollars in water damage simply by turning the valve off at the first sign of trouble.