I have a natural gas furnace. My problem with it is that while sometimes everything works fine, there are times it doesn't. For instance right now I have the thermostat set to 65 yet it's dipping to nearly 55, actually just kicked on as I started type this sentence. Earlier, when I was at work I had it set for 60, was just fine when I arrived home. Basically what's happening is it has periods where everything works fine but then has periods where it doesn't seem to work or takes way to long to finally kick in and start heating. I originally thought the old thermostat might be going out so I replaced it. Wired up everything correctly but still no luck. Money is real tight right now, and I mean damn tight so a repair man is out of the question. Is there anything I could possilby check for. Any help will be greatly appreciated.