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.
Is an expansion tank really necessary?
If your home has a “closed” plumbing system, then yes, you'll need an expansion tank. You see, homes have either an open or a closed plumbing system. A closed plumbing system prevents water from flowing in the reverse direction (i.e., water won't flow back into city lines once it enters your home's pipes).
What happens if you don't have expansion tank?
As plumbers know, the expansion tank equalizes pressure throughout the plumbing system by providing a space for hot water to flow into. Without an expansion tank, pressure would be distributed to the entire plumbing system, straining it and decreasing its lifespan.
Does a tankless water heater need a pressure relief valve?
Pressure-relief valves are an essential component of tankless water heaters. The valves allow you to manually release air from the heating chamber when filling the chamber with water for the first time, or during periodic maintenance. The pressure relief valve is similar to an emergency stop valve.
What happens if you don't have an expansion tank on water heater?
Without a hot water tank expansion tank on a closed plumbing system, the water pressure could build and build, getting high enough to damage valves, plumbing fixtures, supply pipes, and even the water heater itself, causing water heater leakage and other serious harm.
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 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.
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 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.
Can a water heater be used as a pressure relief valve?
Note: The pressure relief valve on a water heater cannot be used as the device to control the pressure.
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
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.
Do you need an expansion tank for a tankless water heater?
Some people use a recirculating pump to kept the water in the pipe “HOT” so you get instant hot water at the tap. This can be done with a “tankless water heater”… but doing so create “an unofficial tank” in the piping of the house. Therefore, you need an expansion tank in that cases.
Do you need a separate water tank for a hoit boiler?
If so, then if you refer to the type of hoit water, heating boiler we have in the UK, then they are directly fed from the main water supply. So do not need a separate water tank.
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.
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.
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.
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.
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 expansion tank?
That is where the expansion tank comes to the fore. It simply absorbs the pressure. Half of the tank is filled with water and the other half is filled with compressed air. The expansion tank also consists of a butyl rubber bladder.
What Size Of Expansion Tank Will Fit My Water Heater?
Now that you have an answer to the question, “do I need an expansion tank on my electric hot water heater?” You will have to check the size that will fit your closed water supply system. To do this, you will need to consider two factors.
What is expansion tank?
Wrap Up. An expansion tank is a small tank that is placed near a water heater. It reduces the pressure on the wall of the heater tank, thereby making the unit to last longer. They are usually cheap and easy to install. If you use a tankless water heater, there is no need to fix this device.
How Does an Expansion Tank Work?
To know how an expansion tank works, you will need to know what happens in a water heater. If your heater converts cold water to hot, the liquid expands, thereby adding pressure to your pipes.
Why is a water tank important?
Well, the tank prevents your plumbing from leaks and bursts and leaks. It performs this task by carrying the extra water while handling any changes in water pressure. You can even see it as a backup to protect your closed water system. The reason is that the excess water does not strain the plumbing because it flows into the tank.
What happens if you pull a rubber band on a heater?
Imagine this process as pulling a rubber band. If you apply too much pressure, the band will break. Your heater is the rubber band, as it expands and contracts frequently, this will make leak or burst.
How much water pressure does a water heater hold?
You can find this information printed on the label of your water heater. The amount of water pressure. Sometimes, it might not exceed 30 psi. However, you can get this measurement accurately by using a portable gauge or calling your water supply provider.
Can a closed water system cause plumbing problems?
Most times, these problems occur in closed water systems that work with single valves. But if your water supply system allows heated water to move into the municipal supply, then your plumbing will not have these problems. If many buildings in your city use closed systems, then the public authorities might require the city residents ...
Why do you need an expansion tank with a closed loop system?
Why you need an expansion tank with a closed loop system. The brief answer? An expansion tank will prevent damage to your water heater and plumbing system. Here’s the more detailed answer... Like we mentioned in the beginning, a closed system creates a single path for water to flow into (but not back out of) your home.
What happens when water is heated?
However, when water is heated, its volume expands (this is called thermal expansion ). When the water volume expands, it puts extra pressure on the tank.
What is a closed plumbing system?
A closed plumbing system prevents water from flowing in the reverse direction (i.e., water won’t flow back into city lines once it enters your home’s pipes).
Does an expansion tank void a warranty?
Because it reduces pressure, an expansion tank prolongs the life of your water heater. In fact, some manufacturers may void your water heater warranty ...
Can a water heater be void without an expansion tank?
In fact, some manufacturers may void your water heater warranty if you have a closed plumbing system without an expansion tank. Now that you know why you need an expansion tank, let’s look at how to tell if you have a closed plumbing system.
