Heating question

[Noel]

I have steam heat in a 1 family house with 2 levels and an unheated basement. I set the thermostat at 74 ( its an old house with recent new windows ). Lately, the temp outside has been on the mild side, and I have a very sunny south exposure which warms up the facing room pretty much when the sun comes out. When this happens, I have the tendency to lower the temp to 69-70 for about 5 hours. Of course, by the end of those 5 hours, the sun is gone and the room is getting cooler. I reset the thermostat back up to 74. Now, someone told me I am causing the boiler to work harder to bring it up back to 74, so I am not saving much gas that way. He said to leave it at 74 , even when the sun enters. Do I save money that latter way?

[Mikepier]

No, the boiler is not working harder. You are doing the equivelant of what a programmable thermostat does, lowers the temp when it's not needed, and raising it when it is needed. Your only talking a matter of 4 degrees. If you heating system is working good, it should warm up the area in about half hour tops. The advantages of saving fuel cost and your boiler being off for a long period during the day far outweigh the disadvantage of having the boiler stay on longer to meet the desired temp in your house.

[JoeSpareBedroom]

Maybe. Does the sun keep the temp at or near 74? If so, why turn down the thermostat. If the sun's adding that much heat, the boiler won't run anyway.