With the temperatures dropping to an all time low this winter, you can bet furnaces are working extra hard tonight to keep you and your family warm. That is if it's still working. With temperatures down to below freezing it's not the time for your heater to go down. But it's happening all across the tri-state because the furnaces are working overtime. Tonight we tagged along with the maintenance crew with g-r freeman who says most of the problems can be avoided. With five lively kids the keen household isn't always concerned with appliances. "Everything's been working fine," says Mike Keen. Until last night when the furnace went out. "You don't notice it until the morning and it's very cold." That's when they called in the maintenance man who points out the problem was avoidable. Replace your filters. "You can never overstate the value of maintaining the equipment," says Paul Freeman. It's something the Keens say they normally do. "Honestly we neglected to have it down during the holidays." You can really see the difference. "You're losing efficiency adding wear and tear and shorting the life cycle." This isn't the only house call for Freeman and his team. "So far this week we've changed out three complete systems." Which means the maintenance men are "burning the midnight oil." The problems can be serious leading to things like carbon monoxide poisoning or just minor but they're always a hassle in this cold. "It never breaks when it's 60 degrees." That means when the weather is that warm remind yourself to get a furnace check up. Something the Keens will keep track of "a big sharpie marker put a date on it where we can see it" so the kids can worry about dancing for fun not to keep warm. GR Freeman is making it easier to get a regular checkup for your furnace. Click Here for more information you need about heating and fixing heating problems.