Why add a tank to a tankless water heater?
- they take longer to deliver hot water
- the water temperature is inconsistent when multiple outlets are on simultaneously
- they cannot provide hot water during a power outage
Is a tankless electric water heater worth it?
Rewiring your house can easily add as much as $5,000 to the cost of installing a tankless water heater. Tankless models save space, offer longer warranties. Many homeowners, however, see benefits of a tankless water heater beyond energy savings. These heaters also save space with a compact design, last longer and are better for the environment because a rusty tank doesn’t end up in the landfill.
Is a water heater expansion tank really needed?
Expansion tanks ARE needed when a water service has a check valve or a backflow preventer installed. In my defense, I retired in 1988 before backflow preventers became code in my area. Back then the added pressure caused by expanding heated water had a place to vent.
Should I get a tankless water heater?
[Checklist] Tankless water heaters are gaining popularity because they take up less space than a traditional hot water tank. So if your old water tank needs to be replaced or repaired, you might want to consider upgrading to a tankless unit.
Do you put an expansion tank on a tankless water heater?
The IPC does not specifically require a thermal expansion tank to be installed with tankless water heaters. However, if a storage tank is used in conjunction with a tankless water heater in a closed system, which is sometimes the case with recirculation, then a means of controlling thermal expansion must be provided.
Where does the expansion tank go on a tankless water heater?
Your expansion tank can be anywhere on your plumbing system and does not need to be installed in close proximity to the water heater. It is most commonly installed using a “T” at the cold inlet to the water heater. But, functionally, it can be installed anywhere on the cold inlet line.
How big of an expansion tank do I need for tankless water heater?
Typically a Thermal Expansion Tank is a small metal tank - usually either 2.1 gallons or 4.5 gallons. The ZEP1, however, is designed specifically for use with either point of use or tankless water heaters with up to 2 gallons of water volume. The set point for this type of tank is 140°F.
Does a tankless water heater need a pressure tank?
Most time no, some time yes. If their is backflow prevention device, check valve or other similar device installed on the cold water input. Their is case were you need an expansion tank with a tankless system. For a thankless water heater itself, you generally don't need one unless recommended by the manufacturer.
What is needed to install a tankless water heater?
Tankless water heaters provide hot water on-demand. Gas units require a gas line, adequate combustion air, a vent to remove combustion gas and an electrical outlet to power the unit. While they last longer than tank-style water heaters, they are more costly to install and often require upgrading your gas line.
Do you need a plumber to install an expansion tank?
Installing an expansion tank can be done by yourself if you have moderate to expert plumbing knowledge and experience. Otherwise, let a professional plumber do the job for you.
What happens if expansion tank is undersized?
An undersized tank can result in a large pressure swing from start up to operating stages. High water storage will lead to the bladder rubbing against the tank wall with each cycle. The bladder could wear due to these high-water volumes. It is therefore important to make sure you have sized your tank correctly.
Are expansion tanks worth it?
An expansion tank is always highly recommended if you have a 'closed-loop system' caused by any kind of check valve or pressure regulating valve installed on your house's water supply line. A common illustration compares having high water pressure in your home to having high blood pressure.
What happens if expansion tank is too small?
If the expansion tank you purchase is smaller than what your system requires, the excess pressure from the expanding hot water will cause relief valve discharge.
How much water pressure does a tankless water heater need?
Specifications for tankless water heaters include requirements for minimum flow rates to activate them—usually around 0.5 to 0.75 gallons per minute (gpm), as well as minimum and maximum water pressure (usually 15 to 150 pounds per square inch).
Why does hot water run out quick when you have a tankless water heater?
Many times, this is just due to too many faucets being run at once, like your shower and the kitchen sink. For example, taking a shower and running the dishwasher at the same time can stretch a tankless water heater to its limit.
What size gas line do you need for a tankless hot water heater?
¾-inchA typical tankless water heater will need a ¾-inch gas line. However, if there is sufficient pressure and the run length is short enough, a ½-inch line may be sufficient with certain tankless water heaters, such as the Noritz EZ Series.
Where is the expansion tank normally located?
Expansion tanks are normally installed above the water heater on the cold water line before it enters the water heater; however, they can really be installed anywhere on the cold water line prior to entry into the water heater.
Does the expansion tank go on the supply or return?
1. The expansion tank is installed on the supply-side of the boiler system. Its sealed-in air pre-charge prevents water from entering the tank until the system pressure begins to rise.
Where should an expansion vessel be installed?
The expansion vessel should be installed vertically above the pipe with the water connection at the bottom and the air valve upper most. Expansion vessels are supplied pre-charge with air, this may be increase or reduced via the air valve to suit site conditions.
How far away can expansion tank be from water heater?
The items which should be installed in sequence in the cold water line are (1) the EXPANSION TANK must be installed at least 18 inches away from the cold water inlet fitting on the water heater, (2) the PRESSURE GAUGE, and (3) the PRESSURE REDUCING VALVE, if required, see Figure 1.
Why does a tankless water heater stop heating?
Because the water distribution system is now an “open” system (i.e., a hot water outlet is open), any thermal expansion is relieved through the open hot water outlet and no pressure increase can occur. When the outlet is closed, the system becomes a closed system but, since the flow has ceased, the tankless water heater stops heating the water.
What is a system B water heater?
System B: Water distribution system with tankless, on-demand water heater (electric or gas) with a storage tank . The water service line has a backflow preventer (such as a dual check valve at the water meter). In this system, an unfired hot water storage tank may be required to provide for hot water recirculation to lessen the “wait time” for hot water to arrive at any fixture. Or the storage tank might be required to provide for large simultaneous hot water demands (that the tankless water heater cannot produce without the storage). For either reason, as the hot water storage tank cools off, a circulation pump is switched on to cause flow out of the storage tank, through the tankless water heater and back into the storage tank until the water in the storage tank is at an acceptable temperature level. Because there will be times where no hot water outlet is opened during the time that the tankless water heater is heating water, the water distribution system is a “closed” system, therefore, a means for controlling pressure increases due to the thermal expansion must be provided.
Why is the water distribution system closed?
Because there will be times where no hot water outlet is opened during the time that the tankless water heater is heating water, the water distribution system is a “closed” system, therefore, a means for controlling pressure increases due to the thermal expansion must be provided .
What happens when a tankless water heater is closed?
When the outlet is closed, the system becomes a closed system but, since the flow has ceased, the tankless water heater stops heating the water. Therefore, methods for controlling pressure increases due to thermal expansion are not required.
Why is the circulation pump on in a tankless water heater?
For either reason, as the hot water storage tank cools off, a circulation pump is switched on to cause flow out of the storage tank, through the tankless water heater and back into the storage tank until the water in the storage tank is at an acceptable temperature level. Because there will be times where no hot water outlet is opened during ...
What is the IPC for thermal expansion?
Section 607.3 of the 2012 International Plumbing Code (IPC) provides the requirements for controlling pressure caused by thermal expansion. The requirements contained in paragraphs 607. 3 and 607.3.1 do not specifically distinguish between thermal expansion from a storage water heater, a tankless water heater, or other system equipment. Paragraph 607.3.2 does specifically require a device for controlling pressure “when there is a backflow prevention device, check valve or other device installed on the water supply system utilizing storage water heating equipment such that thermal expansion causes an increase in pressure.”
When there is a closed system with a heating source, there is a potential for pressure increases from thermal expansion?
When there is a closed system with a heating source, there is a potential for pressure increases from thermal expansion. This is the case with tankless water heaters installed with a recirculation loop and a storage tank. Therefore, a device, such as a thermal expansion tank, must be provided to control the potential pressure increase.
Is an Expansion Tank Required for a Water Heater?
A closed plumbing system prevents the water from flowing in the reverse direction. That means the water will not flow back to the city lines. In the case of an open plumbing system, you will find no pressure or stress on the water heater. Such cases will not require an expansion tank.
What Happens if you Choose the Wrong Size of the Expansion Tank?
Buying the exact right size of the expansion tank is quite desirable when picking the best expansion tank for your water heater. However, if you are in doubt, or if you cannot find the expansion tank of the size mentioned, it would be a good idea to err on the larger size than switching to a smaller one.
What Would be the Water Heater Expansion Tank Installation Cost?
The cost for installing a water heater expansion tank would range across $ 145 to $ 350. In fact, the purchase cost for an expansion tank would begin at around $ 30 to $ 50 if you are going for a DIY expansion tank. The cost can go up to $ 350 for a professional expansion tank.
How to determine the size of water heater expansion tank?
You need to check the size of the water heater you may have. You can check out the information on the size of the water heater on the label on your water heater. You can also find the information in the instruction manual as well. The second factor you will need to check for determining the water heater expansion tank sizing is the water pressure in your plumbing system.
Why do you need an expansion tank for a water heater?
Why do you need an expansion tank for a water heater in a closed plumbing system? Having an expansion tank will prevent damage to the water heater or even the plumbing system. A closed plumbing system creates a single path for the flow of water and when the water is heated, it gets its volume expanded due to thermal expansion. This can put extra pressure on the tank or plumbing system. Using an expansion tank reduces the pressure and thus you end up preventing the damage to the heater and plumbing.
How much pressure does a water heater bladder need?
The bladder will expand and contract thereby absorbing the expanded water from the water heater. Most of the expansion tanks come with 12 to 40 psi pressure, however, before you can install the expansion tank, you should ensure that you have matched the system pressure.
Why does my water heater have condensation?
You may notice condensation on the outside of the water heater tank. This can result from too much water in the expansion tank. This can even happen when the temperature setting on the heater is extremely high. Too much condensation can result in electrical problems if the water drips onto the electrical components.
What is the difference between electric and tankless water heaters?
Tankless water heaters usually have a limit on how many degrees the water can be heated for a particular rate of flow. Electric tankless water heaters are usually less performant in that respect th
How often should I flush a tankless water heater?
One other point: tankless water heaters require regular descaling to ensure long life. Tank water heaters are recommended to be flushed annually, but I've seen tank water heaters last 15–20 years having never been flushed. On the other hand, I've seen tankless heaters fail within 5–10 years due to hard water buildup in the heat exchanger.
How much does a spot water heater cost?
The spot heaters would be no more than 1kW to 2kW max. The smallest are now approaching a $50 price tag.
What are the issues with central plumbing?
One of the issues with a central system is the distance, the run length from the tank to the faucet. The central scheme is simply silly, from that perspective. It came to be as indoor plumbing became the norm. A home had a kitchen 5–10 feet from the tank, and one bathroom, not that much further. That was, say, a 1200 Square Foot home. Homes grew, bathrooms got added, at home laundry on top, the tank got bigger and moved fro
What is the purpose of a spot unit?
Remember, in this scheme, the purpose of the spot units is not for ongoing volume, it’s for eliminating initial cold flow.
Can you go wrong with a tankless water heater?
If you already have some form of gas (natural or LPG), you can't go wrong with tankless, but electric tankless units are a different story. Most of the electric tankless units you might find in a big box store are undersized and underpowered, and will not provide a good experience. The only brand of electric tankless water heater that I recommend to my customers is Stiebel Eltron, and I've had good success with their units.
Can a small spot heater heat water?
The small spot heater can only heat up a small amount of water, let’s say one minute’s worth; turn the tap on, the spot heater immediately delivers hot water, with its intake coming from the central tank, the water incoming to the spot heater is initially cold/cool/cooler from sitting in the pipe, as the water runs, hotter water comes in from the central heater, and the spot heater no longer does anything.
What is the Purpose of an Expansion Tank?
A water heater expansion tank acts as an overflow device. It absorbs the excess created when water volume expands as a result of applied heat. It also accounts for changes in supply pressure caused by new water entering the tank.
What Size Water Expansion Tank Do I Need?
Which one to choose depends upon two main factors: the size of the water heater (capacity in gallons) and the water pressure in the piping system. This information can be acquired on the heating unit’s factory label and/or by phoning your local water supply company.
What is the best tank for a 50 gallon tank?
For a standard 50-gallon tank, the AMTROL ST-5 Thermal Expansion Tank is Amazon’s Choice pick and a best seller! For a portable option, try the Watts DET-5 5 Gallon Potable Expansion Tank . Let’s review each item in more detail. Best of all, whichever one you chose can be delivered right to your front door in as little as two days! Go online today and check out each model!
How does a water expansion tank save money?
A water expansion tank could save you money in the long run by reducing the costly plumbing and appliance repairs often associated with thermal expansion. If you have banging pipes, leaking faucets, running toilets, or a defective water heater, washing machine, or dishwasher, chances are your home is suffering from the after-effects of thermal expansion.
Why is it important to install a water expansion tank?
It will help in the long run by preventing both costly plumbing repair bills and premature appliance replacement. The following is a list of household problems caused by thermal expansion: Banging pipes. Short water heater life.
How many gallons of water does a 50 gallon water heater hold?
It has been estimated that a standard 50-gallon water heater tank expands to approximately 52 gallons when heated to a temperature of 120 degrees Fahrenheit. This additional water volume causes an increase in pressure, which, if significant enough, can damage your water heater, plumbing fixtures, and water pipes over time.
Why do water heaters need expansion tanks?
It is usually required by local building codes to have a water heater expansion tank. Expansion tanks are used to help protect against water heater explosion. Let’s explore this idea below.
What Is An Expansion Tank?
Expansion tanks (aka Thermal Expansion Tanks) are essentially safety devices to help you minimize the risk of damage to your hot water tank.They are an "add on" to your existing hot water heater and are often installed on the water supply pipe to the water heater.Normally this is on the wall next to or very close by your hot water tank.
How hot does a 40 gallon water heater get?
As the water in your hot water heater gets hotter and hotter - it expands.Let's say a 40 gallon tank has a water temperature that is curently at 90 degrees Fa herenheit.When that water is heated to 140 degrees Fahrenheit - it will expand by almost one-half gallon. You can help to prevent this extra expense by having an expansion tank installed.
What is thermal expansion protection?
Thermal expansion protection is required on new water heater tanks. Thermal expansion protection can be done 3 different ways: installing a thermal expansion tank properly sized for the tank. Thermal expansion is caused by changing the temperature of the water. When water is heated, water expands. So, 40 gallons of water at 50 degrees coming ...
What happens when a water heater is stressed?
The stress of this increased pressure shortens the life of the water heater and frequently results in pipes bursting, leaking fixtures and running toilets.
How does thermal expansion affect water?
Thermal expansion is caused by changing the temperature of the water. When water is heated, water expands. So, 40 gallons of water at 50 degrees coming into the house, when it's heated to 120 degrees is approximately 40.5 gallons of water, an increase of approximately 0.5 gallons. The excess water has to go somewhere, so it either causes leaks in the house, stretches the water pipes in supply lines, leaks out of the relief valve or pushes backwards through the meter (if there is no dual check valve or backflow preventer), but basically when the water has no where to go the pressure in the system increases.
What happens when water has no place to go?
The excess water has to go somewhere, so it either causes leaks in the house, stretches the water pipes in supply lines, leaks out of the relief valve or pushes backwards through the meter (if there is no dual check valve or backflow preventer), but basically when the water has no where to go the pressure in the system increases.
Can a hot water heater cause a leak?
You see, the normal thermal expansion that occurs as the hot water heater actually heats your water can place alot of stress on your plumbing pipes.This stress can cause cracks which then cause leaks and well, we don't have to tell you what happens when your pipes begin to leak.The cost to detect and repair water pipe leaks can be expensive.
