Well a lower setting on your hot water heater actually DOES save a lot of energy... much more than changing light bulbs because heating water takes a lot of energy. It doesn't even out to use less of the hotter water because the thing is, most of the time the water is being kept hot but it's not in use. At most you're using it two hours out of 24 hours, wouldn't you say? On the other hand, I remember it's a health hazard to set your water heater below a certain temperature... if i remember right it's 130 degrees fahrenheit, but you might want to look this up. Below that point, bacteria can grow in your water tank. Anyone know what the temp should be in celcius?
Recently i was researching the largest energy drains in households for an article i was writing, and i had a few surprises. Everyone thinks lightbulbs but they are only a tiny percentage of your electric bill. Where you can get the most savings is on your large appliances, and after the several articles i read, i started to believe that if your appliance is more than ten years old, it's better to get a new one because the energy savings from design development and wear are very significant.
The most important items to think about are:
Air conditioning. Air conditioners are the number one cause of energy shortages and black outs. It's worth it to get a new, energy efficient one. ALWAYS use fans along with your air conditioner because it has a huge impact on reducing your useage!
Ceiling fans are not only great for improving the effectiveness of your air conditioner (or allowing you to get away without one), but it also greatly helps reduce your heating costs if you get one that is reversible and will slowly push the heat down from the ceiling.
Then look at your hot water heater. Gas is more efficient than electricity in heating water or anything else. Make sure your unit is relatively new. Compare carefully for energy use when buying a new one. It will pay for itself in savings in just a few years. If you wish, you can even call the utility company and do some number crunching to find out how many months it will take for a new appliance to pay for itself. Also, some people now use solar water heater boosters. These work very well and reduce your costs.
Your refrigerator is also very important. It is best to replace it after ten years because the savings are significant. Each month, remove dust from the vents and back of the refrigerator. Play with the thermostats on your refrigerator and freezer until you have it cold enough, but not more than you need. Check and clean the seals regularly so there are no leaks. And how many people out there leave the door open while they're making a sandwich?
Bad, very bad.
When i purchased my frige, i was fooled by the energy label so i want to mention this: energy labels only compare apples to apples. I bought a frige with the freezer on the bottom because i like the design better. The energy label indicated it was highly energy efficient, but i didn't know it was only comparing to other models with the freezer on the bottom. The ones with the freezer on the top are all more energy efficient because cold air sinks. Same with side by side designs. They only compare to other side by sides. Again, the friges with the freezer on top are more energy efficient.
Check out your furnace, too. If you have an old, inefficient furnace like mine, start budgeting to replace it because it's like plugging any other drain in your house only this one is bigger! Also, make sure you get an annual tune up for your furnace and change filters monthly. If your heating ducts aren't insulated, insulating them can yield good savings. And close off any room you don't use every day and don't heat it unless you need to. I am able to close off three rooms in winter and this is very significant to my heating bill!
I'm afraid i don't know much about boilers or other forms of heating, but perhaps someone else who lives with other heating can speak up about this.
Other appliances to look at are your washer and dryer and dishwasher. You get the picture, it's much like the considerations for the other appliances. The clothes washer is anothe case where the energy labels only compare apples to apples. Side loading washers are much more energy and water efficient than top loading.
Which reminds me, the other thing to consider is your useage. We've been talking about that a bit already, but for instance laundry... do you have to wash your towels after one use? If i can use one towel for a week, that uses 1/7th the energy and water. Something to think about!