Water heating can be provided for your home in a variety of ways. The different kinds are tank, tankless, indirect and instant/booster. The most common is the tank water heater.
Regardless of the fuel use or what the manufacturer says, these tanks should be drained at least once a year and only about a gallon of water. The reason for this is the cold water pipe that goes into your tank only goes about three-quarters of the tank.
The hot feed pipe only goes about a third into the tank. Both pipes enter the top of the tank, which means that any sediment that enters the tank will sit at the bottom of the tank. There is no other way to remove the sediment other than draining from the bottom of the tank. If your pipes freeze during the winter and you will notice only the hot water pipe that does.
The reason for this is when water is under pressure it's very difficult to freeze it, so that the cold water pipe does not freeze. When the hot water is not in use for a period of time, like over night, the tank takes up the pressure in the pipe. This makes it easier for the hot water pipe to freeze. If both pipes freeze, then the temperature where they are freezing is so cold even the cold water pipe under pressure freezes. If it takes a long time for you to get hot water during the winter it's because the pipe gets cold and extracts the heat from the water and it has to heat up the pipe with your hot water before you get hot water. The solution to all of the above is to install an auto circulation pump. It is thermostatically controlled with a timer and on/off switch.
This unit installs under the sink to which the pipes that freeze and if you are the least bit handy, you can do it yourself. The way it works is there is a thermostat inside the unit that recognizes the temperature drop in the hot water pipe. When this occurs, the pump comes on and circulates the water in the hot water pipe through the cold water pipe back to the water heater. Thereby maintaining the pressure and temperature in both lines. Your pipes will never freeze and when you turn on the hot water tap you will have hot water almost immediately. You can turn this unit on only during the winter with the use of the on/off switch and /or only at night with the use of the timer.
If your pipes freeze this unit will resolve your problem and "YES" it will save you money. Where ever possible all the hot and cold water pipes should be insulated. Another consideration is water damage and there are ways to prevent it. The following link is a fine example. Prevent Costly Water Damage! All tank water heaters should be wrapped with insulation. The reason for this is the cost of actually using hot water pales in comparison to the cost of maintaining the temperature of the water in the tank. People tell me that they wash clothes everyday.
It takes less than three minutes to fill your washer with hot water and not 45 minutes to wash the clothes. The vast majority of cost for water heating with a tank comes from maintaining that temperature of the water in the tank. If you took a stop watch and timed the actual time you see the hot water come out of the tank for a family of four, it would be less than two hours. That means that more than 22 hours a day the temperature in the tank is being maintained. Even if you were excessive with hot water, it would still be more than 20 hours a day. What the water heater jacket does is maintain the temperature in the water heat longer with insulation. This will reduce the cost of water heating dramatically. What voids the warranty with these jackets is when you cover the pressure relief valve. With gas unit you cover the draft diverter and/or the bottom that prohibits air to the burner.
If you follow the instructions with these jackets, you will not have a problem. Furthermore, if you wrap the water heater with a jacket and drain one gallon of water from it annually, you will prolong the life of the water heater from ten years to eighteen. Tankless domestic hot water heating is not cost effective. Though there is no tank as the term implies, the temperature in the boiler must be maintained in the summer in the event you require hot water. Though the boiler has a more efficient burner than a tank water heater, the temperature in the boiler is quite higher. The ambient temperature of cold water in a home is usually 55 degrees F. and the temperature of the hot water for these systems is usually 110 degrees F.
This wide temperature difference causes the corrosion on the coil inside the boiler to accelerate. This increases the cost of getting hot water from these systems and it is not unusual for you to run out of hot water. These coils should be cleaned at least once every two years. The solution to this system is getting a tank water heater, sometimes an indirect and instant/booster system. Indirect domestic hot water systems are excellent systems depending upon the type of boiler you have. If you have an old boiler that has a tankless coil, the problem of maintaining the temperature in the boiler persists. Though you do get better hot water with installing an indirect system to your boiler.
The new energy efficient boilers resolve this problem. In an old boiler, regardless if it's gas or oil, the volume of water in these boilers can be as much as 50 gallons. The newer boilers have 5 gallons or less in them and the burner and boiler design is what makes them efficient. The older boiler requires the temperature be maintained due to its volume in the event heat or hot water is needed. On new boilers due to the volume of water in it, the temperature can be risen so rapidly that maintaining the temperature in the boiler is not required. The temperature of the water in new boilers is maintained to avoid freezing and is rarely ever needed and can do so rapidly that the cost is insignificant.
There are two types of indirect systems. One uses a coil and the other does not. In new boilers the size of the boiler prohibits a coil from being inserted into them. With indirect systems the coil is in a tank located along side the boiler. The boiler water is pumped into the coil inside the tank and heats the domestic hot water rapidly. With the system that does not use a coil, the boiler water is pumped into a tank that surrounds another tank. The inner tank has the domestic hot water in it. Both types cost more than a tank water heater to operate, but are less than a tankless system. They cost more to purchase and install than any other system. The advantages to this system are longevity, it will probably outlive you, and the amount of hot water it produces is staggering.
If the system is installed properly you could fill a hot tub with hot water, take endless showers one right after the other, wash clothes and use the dishwasher at the same time and still not run out of hot water. Instant/Booster domestic hot water systems are good systems but have concerns with them, when used as a primary source for hot water in a home.
With gas units these systems require a considerable amount of gas water columns to operate. Most residential areas do not require such use and the Utility may not provide for it in there under ground lines. For this reason, electric units are more common. Electric instant systems cost less to operate the tank electric water heaters but more than gas and oil systems. You could reduce the cost of an electric tank water heater by putting a timer on it and wrapping it with an insulation jacket. Depending on the use of the timer, the electric water cost of operation could even compete with gas and oil systems. Which is better than an electric instant system.
Eemax Electric Water Heaters: Single Point & Flow Control Series This is a fine example of an electric Instant/Booster system. This systems shines when it is used as a supplement as with space heating. Let's say you have a whirlpool tub and the capacity of water in the tub is greater than the capacity of water in your tank. Most homes will raise the temperature of the water in the tank to accommodate the tub by mixing cold water with the hot water going into the tub. Unfortunately this increases the cost of maintaining the temperature of the water in the tank dramatically. By installing instant electric water heater in or near the bathroom where the tub is located resolves this problem and is very cost effective. For people who have water heaters on the second floor and especially those who had to deal with cleaning up afterwards, this is must have product.