I had a real problem the other evening. I had been having a lot of heat flashes lately, and I thought Winter time was going to be a cakewalk. I was frustrated when I went for three weeks without a single heat flash, and it was the coldest section of winter. I couldn’t get warm, no matter what I did. I knew the gas furnace was running, because I could hear it turning on and off. That’s when I realized the gas furnace was turning on and off more often than it should be. There was truly little heat coming from the air vents. I knew I had a problem. I called the Heating plus Air Conditioning corporation and told them what was going on. They sent a Heating plus Air Conditioning serviceman to the house. He said the gas furnace was working fine, despite the fact that he was distraught there was a blockage in the air vents or in the HVAC duct. He had to get a professional HVAC duct cleaner to the house. Luckily, their corporation had a repair with the cleaning unit installed. He was able to get a repair tech who was able to run the machinery to come to the house that day. The 1 air vent was almost totally clogged with debris, but it was the air filter that was my main problem. The air filter was totally clogged with dirt and debris.. There was no airflow getting through the air filter and it was affecting my gas furnace. He said I had to remember to change the air filter, or next time I may not be so fortunate. He said it could have destroyed my gas furnace.