Maintaining your large kitchen appliances is part of a smart home energy efficiency plan.

Refrigerator/freezer
Energy-efficiency experts tell us to focus our efforts on the biggest energy hogs in the house, and that definitely includes the fridge. Because it cycles on and off all day, every day, the refrigerator consumes more electricity than nearly every appliance in the home save for the HVAC systems. The average refrigerator costs about $90 per year to operate, according to the U.S. Department of Energy. The good news is that a few simple adjustments can trim roughly $38 to $45 off those utility bills.
1. Adjust the thermostat. By setting the thermostat colder than it needs to be, you might increase your fridge's energy consumption by as much as 25% on average. Adjust the refrigerator so that it stays in the 37-40 degrees F range. For the freezer, shoot for between 0-5 degrees F. You could save up to $22 per year. If your model doesn't display the current temps, invest in two appliance thermometers (one for the fridge, one for the freezer). They cost roughly $3-$20 apiece at online retailers.
2. Clean the coils. As dust accumulates on the condenser coils on the rear or bottom of the fridge, it restricts cool-air flow and forces the unit to work harder and longer than necessary. Every six months, vacuum away the dust that accumulates on the mechanism. Also, check to see that there is at least a 3-inch clearance at the rear of the fridge for proper ventilation. This routine maintenance can trim up to 5% off the unit's operating cost, says energy savings expert Michael Bluejay, saving you about $4.50 a year.
3. Use an ice tray. Automatic ice makers are a nice convenience, to be sure, but it turns out the mechanisms are energy hogs. An automatic ice maker can increase a refrigerator's energy consumption by 14% to 20%, according to Energy Star. By switching off the ice maker and using trays, you can save about $12 to $18 off your annual electricity bill. Most units require little more than a lift of the sensor arm to switch them off. To reclaim the space remove the entire unit, a simple DIY job on many models.
4. Unplug the "beer fridge." Many homes have an extra fridge that runs year round even though it's used sparingly. Worse, these fridges tend to be older, more inefficient models. By consolidating the contents to the main fridge and unplugging the additional unit, you eliminate the entire operating cost of a fridge. The second-best solution is to make sure the extra fridge remains three-quarters full at all times. The mass helps maintain steady internal temps and lets the fridge recover more quickly after the door is opened and closed, according to the California Energy Commission.
Ovens and ranges
"Green" cooking all comes down to proper time and space management. By using gas and electric stoves more effectively, you can painlessly save a few dollars a year.
5. Cut the power early. As anybody who's ever bumped a burner on an electric stove can attest, those heating elements stay hot long after they've been switched off. Put that residual heat to work by shutting off the burner several minutes before the end of the cook time. The same technique can be applied to the oven. The savings can add up to a couple bucks every month.
6. Match the burner to pan. When a small pan is placed on a big burner you can practically see the money disappearing into thin air. By matching the burner to the pan, electricity won't be squandered heating the kitchen rather than the food. The reverse is true, too. A small burner will take considerably longer to heat a large pan than would an appropriately sized burner. For gas stoves, don't let the flames lick the sides of the pot. Follow these tips and watch the utility bills shrink by a few dollars a month.
7. Do away with preheating. You can save about $2 a month by not preheating your oven (20 cents per hour to operate electric oven; eliminate 20 30-minute preheats a month). Many cooks agree that the practice is wholly unnecessary for all but a few recipes, namely baking breads and cakes. This approach may add a few minutes to the overall cooking time, but it eliminates all that wait time on the front end.
Dishwasher 
As with washing machines, most of a dishwasher's energy needs go to heating the water. Still, says Lane Burt, an energy policy analyst with The Natural Resources Defense Council, a 10-year-old dishwasher can be made nearly as efficient as a newer model simply by knowing when and how to run it. Follow a few simple tips, and you can reduce your annual utility costs by roughly $35-$54.
8. Manage the load. Most dishwashers use the same amount of water and energy whether they're run full or half-full. You can cut your operating costs by one-third or one-half by running the machine only when it's full. It costs about $54 to run a pre-2000 model dishwasher per year, based on government data. Proper load management can save up to $27 each year.
9. Activate energy-saving features. A dishwasher's heated dry cycle can add 15% to 50% to the appliance's operating cost. Most machines allow the feature to be switched off (or not turned on), which can save $8-$27 per year, assuming an operating cost of $54 annually. If your dishwasher doesn't have that flexibility, simply turn the appliance off after the final rinse and open the door.
10.  Use the machine. Many homeowners believe they can save water and energy by hand washing dishes. The truth is that a dishwasher requires less than one-third the water it would take to do those same dishes in the sink. By running the machine (when full), you can cut down the operating time of the hot water heater, your home's largest energy hog. Not only will you save a buck per month, you won't have to do the dishes.