Click, clack, bang, boom, hiss. We have all heard those noises before. Where do they come from you ask? No, not the opening hook to the latest pop song on the airwaves, but from your furnace. This happened to me when I was at my last apartment. My roommates and I were feeling a little cold during the winter months, but that was because we thought the heat was escaping to the attic that we didn’t use. That wasn’t the case because our ceilings were insulated to stop that sort of thing from happening. Next, we thought it could be the windows because it was an old house – wrong again. We then realized it was the furnace. It was making all of these sounds and clicking on and off, and on and off. Also, the programmable thermostat was not staying programmed. It would randomly change from being around 68 degrees to a sweltering hot 80 degrees. We finally called the HVAC technician our landlord recommended. He came out and of course the furnace didn’t act up at all. The tech changed the air filters and called it a day. Later that week the furnace started to make those noises and turn on and off again. The HVAC technician came out again and still said nothing was wrong. It was like the furnace knew it had to be good with the HVAC mechanic around and then once he left, the heater could go back to being bad.This is a classic example of why you should service your heater in the fall.