Just a quick note about furnaces. I know most folks already know this but I had to find out on my own so I'm sharing. Every year when it turns cold enough here to warrant using the furnace, I vacuum out all the ducts and clean out the furnace filter before lighting it off. I did all that and then bumped the thermostat up to call up the furnace. It tried to light. It actually did light but with a very weak flame and not hard enough to open the gas valve all the way. Anyway, after watching a couple of youtube videos, I jumped in and took the furnace apart. What I found down deep in the gas valve inside the actual gas jet, a tiny spider had spun it's web and was restricting the flow of gas so the flame was too small to get the valve to open all the way and the flame would go out. So after cleaning out the web, I tried it again and it fired off and stayed lit. I learned something that will save me money in the future. I hope this is news to some who might have to call out the repair guy.
Ray