Q My family has a vacation home in Vermont, where we spend most weekends. It feels like a waste of gas to keep the water heater on all week, so I'd like to turn it off when we're away. Would it save energy to do that?

A: It sure would, but you'd need to take some precautions. While you're away, the water in your tank would fall below 140 degrees Fahrenheit, which is the temperature needed to prevent the growth of certain bacteria.

You'd think the solution would be as simple as setting the heater to 140 degrees while you're using your vacation home. Water that hot, however, will scald you. So, you'll first need to make sure that your heater has a mixing valve, which will reduce the temperature at your tap to 120 degrees while the water in the tank remains at 140 degrees. If you don't have a valve, your gas company or the person who services your tank can install one. Then, you can safely turn off the heater as you leave your Vermont home and set it to 140 when you return. Just be certain that, when you first turn the heater on, you wait for the tank to come to full heat before you use the hot water. You can test the temperature at the tap with a meat thermometer.

When it's time to retire the old water heater, you could replace it with an on-demand model. This kind of water heater has no tank, so you wouldn't run the risk of bacteria growth that can happen in stored, unheated water. On-demand water heaters, also known as instantaneous heaters, have their plusses and minuses, so get the facts from your fuel dealer or equipment supplier to determine if this option would meet your family's hot water needs. Meanwhile, enjoy your time in Vermont!

Q My kitchen is pretty far from my water heater, so I have to run the water a while before it gets hot. I'm concerned that this is running up my energy bills. The water heater works fine at closer taps, so I know that the water temperature is hot enough. Would I save money by installing an instantaneous water heater under the sink?

A: The best answer is "it depends". A long wait for hot water does waste water and energy. You could save both with an instantaneous water heater, but you'd need to compare those savings to the installation costs. A gas instantaneous water heater requires a fuel line and venting. An electric model probably will require a new electrical circuit and could be more expensive to operate, depending on utility rates.

Seeing as you're prepared to pay the cost of a new water heater, another option could be a demand recirculator for your existing water heater. This device brings water to the tap quickly by using a small pump installed under the sink. This approach lowers water-heating costs because water from the kitchen cold-water pipe is recirculated to the water heater. That reduces the amount of colder water, from outside the house, that needs to be heated.

A demand recirculator costs about the same as a water heater and can be purchased and installed by a plumber. If this interests you, ask your plumber if he or she is familiar with this device and if it would be appropriate for your household's needs

Q My wife and I have been talking about ways to reduce the cost of running our electric water heater. I think that we should put it on a timer that turns the heater off at night and when we're gone for the day. My wife says not to do it because the tank will cool and we'll be paying more to heat the water twice. Who's right?

A: Technically, your wife is right; turning off the water heater at night could lower the tank temperature slightly by morning. However, the amount would be negligible. You'd need to keep your water heater off, constantly, for about a week before you'd make a noticeable impact on your electric bill. So, I wouldn't bother with the timer. There's a better way to save water-heater energy: Insulation.

I suggest that you insulate both the hot and cold pipes within three feet of the tank. Pipe insulation, available at hardware stores, comes in flexible, closed-cell foam sleeves that are usually packaged in three-foot lengths. Choose the right size for your pipe diameter. These slip-on sleeves are easy to install and cover the entire pipe surface, even when bent around corners. Use electric tape over the places where the sleeve ends meet.

If your water heater is in a cold basement, air sealing and insulating the basement will have the double benefit of saving water-heater energy and making your house more comfortable year-round. If you decide to have this basement improvement done, you can find a Home Performance with ENERGY STAR^® certified contractor at www.efficiencyvermont.com/homeperformance. 

Q I've got an electric water heater and I'm thinking of switching to an electric instantaneous hot water heater. Would that reduce my electric bill?

A: Probably not.  It takes the same amount of electricity to heat a given amount of water, regardless of which technology you use. It's possible for a tank-style water heater to use a little bit more energy if the tank isn't insulated and if it's not in a well-insulated part of your home. But the cure for that isn't an instantaneous water heater; it's insulation.

Insulate both the hot and cold pipes within three feet of the tank. Pipe insulation, available at hardware stores, comes in flexible, closed-cell foam sleeves that are usually packaged in three-foot lengths. Choose the right size for your pipe diameter. These slip-on sleeves are easy to install and cover the entire pipe surface, even when bent around corners. Use electric tape over the places where the sleeve ends meet.

Also, keep in mind the fact that a tank-style water heater generally can provide all the hot water you would need at one time. Instantaneous water heaters provide only as much hot water as can be heated on a continuous basis, because they have no reservoir

Q I have a small farm and I must use stock tank heaters in the winter to prevent the livestock's water from freezing. Is there a way of knowing how much of my electric bill is for these heaters? If it's a lot, I?d like to know if there are energy-efficient or non-electric heaters.

A: If you run 1,500-watt stock tank heaters for two hours a day for five months, you're paying about $57 a year per heater. Unfortunately, alternatives are in short supply. Using a bubbler in this climate would not guarantee an ice-free tank and the cost of buying and installing solar-powered heating equipment outweighs the savings on your electric bills.

But there is good news. Your answer is not in your heater but in the tank. You can keep the tank water above freezing longer by using an insulated tank with an insulated cover that leaves only part of the surface exposed for watering. You also can partially bury the tank in the ground and insulate the ground around the tank. These approaches will lower your electricity costs by reducing the amount of time your heater runs. A stock tank heater set up this way will be more energy-efficient

Q I'm thinking about replacing my old hot water heater. Are there ENERGY STAR qualified water heaters? How can I tell if I'm getting an energy-efficient model?

A: Sorry, the Energy Star label is not available for water heaters. But you can compare the costs of operating different energy-efficient models by reading the yellow EnergyGuide sticker on the tank. The EnergyGuide shows the estimated annual energy consumption and operating cost for that model. This should help you compare models and save on operating costs.

I'll add some important safety considerations: Keep in mind that, if your water heater is vented into a chimney, the chimney must be inspected and brought into compliance with current fuel codes. And if you've had any trouble with the "draft" of your old gas or oil water heater, you may want to consider a power-vented or sealed combustion water heater, which does not require a chimney to vent its exhaust gases.

Q I'm replacing my hot water tank. With energy costs so high, is a solar hot water system a cost-effective option?

A: Absolutely. Aside from reducing your energy costs, adding renewable energy to your home is a great investment. We estimate that a family of four spends more than $600 a year operating an electric water heater. Installing a solar hot water system could cost as much as $6000, but the system will supply your family with 70% of its hot water needs, saving you more than $400 per year. You'll get a payback on your total investment in just over 13 years, with an annual return on the investment of over 7% (a lot better than interest rates on a savings or money market account)! If energy prices rise, the return on your investment will increase and the payback period will decrease.

Q I have an 80-gallon hot water tank, but now that my kids have moved out I'm wondering if an instantaneous water heater would be a less expensive option. What can you tell me about these?

A: An instantaneous or "on-demand" fuel-fired water heater can provide plenty of hot water for a household - and do it very efficiently. Look for an "Energy Factor" of .80 or higher, indicating a unit that is very efficient. Such a unit may also qualify for a federal tax credit of $300.

You'll find that on-demand water heaters are expensive to purchase and that there are only a handful of models suitable for home use. Before you take the plunge, give us a call at 888-921-5990 so we can help you determine how efficient the switch to an on-demand hot water heater would be based on energy costs in your area. You may find that trying other energy-saving measures would give you a better return on investment, especially if your 80-gallon water heater has a lot of life in it.

Q How can I make my water heating system more efficient?

A: There are several simple steps you can take to keep it running as efficiently as possible.

Wrap exposed pipes and electric hot water tanks to prevent heat loss.

Install low-flow shower heads and faucet aerators (available at your local hardware store) to regulate hot water demand.

Wash only full loads in your clothes washer, and use cold or warm water whenever possible.

For a free copy of "Your Guide to Your Electric Hot Water Heater" and to learn about more steps you can take to reduce your water heating costs, click here or call Efficiency Vermont at 888-921-5990.

Q Is it really worth it to insulate my electric hot water heater?

A: Hot water heater insulating blankets - also known as jackets - are inexpensive and effective.  Depending on your usage patterns, adding supplemental tank insulation can save up to 500 kilowatt hours annually. Before you get a jacket, check your manufacturer's instructions, to be sure that you won't void your warranty by insulating the heater and find out about the insulation already in the tank. If your tank is insulated with foam instead of fiberglass, you're probably OK. Also, consider the tank's location. If it's in a closet, for example, the small space may be serving to keep the heat in. And don't forget the pipes, which are a common place for heat to escape.  It is usually worth insulating at least the vertical piping immediately above the tank.  

If you use a jacket on an uninsulated electric water heater, you could save about $25 per year in electricity costs. There are additional good ways to save on water heating costs, whether you have an electric or gas unit. Install low-flow shower heads, insulate the hot and cold pipes directly above the water heater (or all of them if the basement is cold) and -- if you do a lot of laundry -- consider an ENERGY STAR washing machine.

For readers who have a gas water heater: Although it is possible to insulate gas water heaters, in most cases it is not recommended because so many portions of the exterior must be kept clear for your safety and for the proper functioning of the unit. Ask your gas utility or the person who services your tank whether it's possible and worthwhile to insulate your gas water heater