Do you connserve mor eneergy by keeping your furnace running or turning it on and off?

Do I conserve more energy keeping my thermostat at 65 degrees throughout the day, or by turning my furnace off during the hours of 9-5 while I'm at work and turning it back on when I get home? Thanks!Do you connserve mor eneergy by keeping your furnace running or turning it on and off?
It depends...on many things. If you have a boiler...then the most efficient thing you can do is turn the thermostat down to 65 as you suggest. Turning it off would in fact damage the unit. While not immediately, the life expectancy of the unit would be significantly diminished.





Many people like to talk about the insulation value and construction quality of the home. While this is good information to have...it's irrelevant to your question. R-values and home envelopes only speak to the homes ability to resist heat loss/gain; not the ';efficiency and conservation of energy'; the furnace can provide as posed by your specific question.





Manufactures record the furnace units efficiency by its peak performance. Peak performance is obtained when the the unit can maximize its heat/cool rise differential (found on the nomenclature plate of the unit). In English: A furnace is at peak performance when it is firing on all cylinders and heating, then re-heating the recently heated air.





In other words...a furnace is most efficient when it's heating a cold house than when it's trying to maintain a 72 degree house once the house has been heated.





Personally, I program my thermo. to turn down to 55 in the day...and rarely is it ever that cold in the house due to good insulation and house envelope.Do you connserve mor eneergy by keeping your furnace running or turning it on and off?
That depends a lot on the outdoor temperature, your house construction and insulation, etc..





Typically it is more economical to set your thermostat to a low temperature, such as 65 so your furnace does not have to work too hard when it is turned back up again.





However, if it is over-sized and capable of heating your home back to a comfortable temperature in just a few minutes that may not be the case.





I have always read to turn it down, not off to conserve energy so recommend you follow those guidelines without knowing more specific information.
The best thing to do is to replace your thermostat with a programmable unit. This will save you 10-15% on your utility bill. It is an easy diy project. For more info, check out the thermostats page at www.hvac-for-beginners.com
If you turn off the thermostat when you leave your home the furnace will work harder and longer to warm the house when you return costing you more. Just turn it down a bit.
Do not turn your boiler off. This is way too much thermal stress on the heat exchanger. Install a setback thermostat to maintain a lower temp, like 60 degrees, for when you are not at home.