Is shutting off the furnace a few hours a day a good way to save heat?

Question

I'm really trying to conserve on oil consumption in my house. I turn down the thermostat, my tenant does so as well. But the furnace still kicks in when the temp drops to what we've set them to.
What I've tried doing is just to shut off the furnace on weekdays. I'm alone, so it's no big deal for me. I turn it back on as soon as the tenant gets back from work.

I'm wondering, does this really help or am I actually using more heat when the furnace restarts after being shut off for 6 hours? It also has to heat the hot water tank (30 gallons).

Thanks for your input!

Answer 1

I would not turn off the furnace completely for many reasons. It is very hard on your furnace when you do turn it on it has to work that much harder. Also it is very hard on your house. You are cooling and heating cooling and heating, there isn't a set temp this way. Keep your temp at 64 or so. If your heat goes on it won't be that often. It is not a good thing for your water tank either. You could create weakness in the lining from constantly up and down heating. It does however take a long time for a hot water tank to cool down.
Better to keep you furnace on though!!

Answer 2

Any savings that you might receive by shutting the furnace off are lost once you turn it back on. It has to work longer to reheat the house. You electrical costs are also affected because the blower must work longer.
You are much better off turning it down by 3-6 degrees or so and then bout an hour prior to the tenant returning home, turn it back up.
A programmable thermostat would help also. You could then program it to turn the heat down abut 3 degrees at night and back on around 6:00am for comfort and then back down again during the daylight hours.

Answer 3

Lets say the temperature rise you desire requires 1000,000 btus of energy to warm the home. Now, lets sat that in a 2 hour period 100,000 btus are dissipated while you are at work but no more will dissipate because the outdoor temp only goes to a given point. You still have to recover 100,000 btus whether it took 2 hours or the entire 6 hours you were gone.
Now assume you left it running while you were gone. The furnace would operate during that time to keep 100,000 btus. SO. Let it run all day or hard while you get home, it still needs to recover the same amount. It does not matter which way you do it. The oil used (or btus recovered/lost) will remain the same.

Answer 4

to know for sure, much more info would be needed. Sounds to me like you are probably not saving much. if any, because the furnace will have to run longer to bring it back up to temperature,and heat the water. And if you forget to turn it back on, and leave, you could have tons of problems, not to mention a ticked off tenant.

You would probably save more by caulking windows, insulating around outlets, getting doors so that they seal up, and things like that. Add attic insulation, anything that stops air transfer. tarps, old newspapers, most anything can be used for this, if the attic is an unused space. of course if you can afford to do it, another layer of thick fiberglass insulation ran perpendicular to the current one will do the best. since heat rises, stopping it there is the best conservation measure you can take. make sure the dampers to any unused fireplaces or stoves are closed too. Even old carpet placed in the attic can help the insulation values. anything that will stop the heat transfer will work to some degree. dead air is the best insulator. that is air that is contained and cannot circulate.

Answer 5

Don't shut it off! (You didn't mention what climate you live in.) Your pipes could freeze, the commensurate damage will far exceed the meager savings. You could be delayed getting home, have an accident, or the temp could just drop faster than you are used to.

If you must, turn it dow to 50 or 55 F which is often the low limit on most thermostats anyway.

Insulation, new windows, more efficient heater will do more in the long run to save $$. You should also consider the value of you and your tenants comfort.

Answer 6

Your furnace will actually have to work harder to get the temp back up if it falls a lot. You are better off turning the heat down and keeping it at a lower temp than turning it off all together.

Answer 7

My cousin tried this. He turned off the heat when he went to work. As soon as he left his wife turned the heat back on. Then just before he got home she turned it off and opened the doors and windows to get the house cold. After one month and bill came in 50% higher than before, he stopped. He sill can not understand why his bill when up. Its a family joke. I am sure you will NOT save any money turning it off. Better to set at a low temperature.

Answer 8

That is a tough call, especially considering the hot water. We use hot water to heat our home, and were advised to leave the boiler at a constant temprature unless we were leaving for an extended period of time as it takes as much enrgy to re-heat the water as it does to keep it hot.

My advice would be to try it both ways for a month and see for yourself if one method uses more oil than the other. You will probably find it is not worth the hassle of messing with the thermostat.

Answer 9

you are using more energy to heat it up after being shut down. try setting your heat on 70 degrees. after your house gets to a certain temp the heater wont turn on as much anyway, and you will save more by keeping it set to a certain temp than you would if you just shut it down and started it back up. sure hope this helps

Answer 10

Don't be so tight! Live a little.