Which is better? Leaving the heating on low or on while I'm in?

kittyQC

Hi there everyone,

I was just wondering if anyone had any thoughts on which is better... leaving the heating on low or turning it on for a few hours everyday?
Basically I live in a semi detached house and I was discussing with a colleague about heating. And he said that basically once it gets cold (say end of September) he leaves he heating on all 24/7 but on low so the house maintains a warm temp and he believed that this is more cost effective than what I do which is to set the timer to come on for a few hours in the morning before work and a few hours in the evening when I'm back before bed (so about 7 hours in total). He says this is wasting energy because you have to heat the walls and everything each time before you start to feel warm.
Is he right?

Cardew

No he is wrong.

Discussed dozens of times in this forum.

Without rehearsing all the arguments; just 2 points:

If you were to go away for, say, a year would you think it better to leave your heating on? How about a month? A week? Well why would it be better for a few hours?

If his principle is correct then you should leave a kettle simmering all day because it wastes heat to let it cool and then warm it up.

If he doesn't understand the laws of physics then tell him to look up FAQ in the Energy Saving Trust and it will tell you that it always uses more energy to keep something at a constant temperature, than letting it cool down and re-heat - like the kettle.