Before taking a shower, it is often necessary to wait a little before the shower. The answer is simple: to wait for the cool water in the hot water pipe to drain and for the hot water to appear before you can start the shower. The zero cold water gas water heater is an innovation to solve this problem. The so-called "zero cold water" refers to the amount of cold water released before bathing can reach almost "zero". It sounds appealing, but before you rush to place an order, let me take your time. I've used three zero-chill water heaters, and this process has taught me a truth: as long as you can install a gas water heater in your home, you can basically install a zero-chilled gas water heater. But not all zero-cold water heaters are equally effective.
["Zero cold water gas water heaters" are all referred to as "zero cold water" or "zero cold water water heaters" below.] 】
01 Contamination of cold water pipes
How is "zero cold water" achieved? The answer is through "recycled water". The system heats up the water heater ahead of time and feeds the hot water into the pipes. The original cold water is returned to the water heater for reheating. But then the problem arises: the water pipes are all one-way, and the water can flow from the water heater to the shower, so how do you get the water from the shower back to the water heater?
The key here is the "check valve" or "H valve". It is responsible for connecting hot and cold water pipes. By applying pressure to the hot water pipe through the water heater, the water can be pushed forward, enter the cold water pipe from the H valve, and then return from the cold water pipe to the water heater for heating. The yellow metal valve of this H-valve is one of the keys.
However, taking this approach raises two problems:
First of all, it is easy to contaminate the cold water pipes, because there is bound to be limescale inside the water heater, and these scales will enter the cold water pipes during the circulation process.
Secondly, it heats up the water in the cold water pipe, especially during the water cycle, and the faucet may not be able to release cold water.
02 The cost is extremely high
Is there any way to avoid both of these problems that can contaminate the cold water pipes? Yes, of course, just with a different way of installation.
In this new installation, a return pipe was introduced. This return pipe is specifically reserved for zero cold water heaters and has no other use. Yes, waste is one thing, but the timing of installation is even more critical: you have to leave room for renovation or you'll miss the opportunity to use the return pipes forever. The angle valve in the middle is the return pipe.
In addition, there are two additional costs that zero cold water heaters face regardless of which way they are employed:
Gas charges
: Since the hot water is also constantly working during the cycle, the natural gas is also constantly being consumed. Although no hot water was being used at this time, the gas meter kept spinning rapidly. This is also the problem of "affordability and unaffordability", which is the most common sentence lamented by zero cold water users.
High failure rate
On the one hand, since the function of zero chilled water is more complex, and a circulating pump is added to the interior, the possibility of failure is greater. On the other hand, zero chilled water works longer than a regular water heater and therefore consumes more components.
03 零冷水≠纯热水≠零等待
When you actually start using a zero-cold water heater, you'll notice that it's probably different from what you imagined. Many people mistakenly think that "zero cold water" means that you can get hot water immediately when you turn on the shower, but this statement is not entirely accurate. It's true that you can get hot water by turning on the shower, but the temperature of the hot water doesn't have to be the temperature you set beforehand. Although the circulating hot water fills the hot water pipe, its temperature drops even if it is only for a minute or two.
At the same time, many people mistakenly believe that with a zero-cold water heater, there is no longer a need to adjust the water temperature every time you use the shower. In fact, when you first turn on the shower, the temperature of the hot water is lower than the temperature of the water later. Therefore, as when using a regular water heater, the water temperature needs to be adjusted once within a minute or two after each time the shower is turned on to avoid burns.
"Zero cold water" is just one feature on a zero cold water heater that can be turned on and off manually. This brings up a new question: when should this feature be turned on? With zero cold water turned on, it only takes one minute to complete the cycle. However, if the wait is too long, the water temperature may drop again. So, do you need to turn it on a minute before every shower, and if you're so meticulous, why not wait a while while standing under the shower?
Of course, some zero-cold water heaters today are equipped with an "induction on" function. As soon as you turn on the shower, it will automatically start the cycle. However, a new problem arose: when the shower was first turned on, there was still cold water, but with a circulating pump, it was possible to shorten the time it takes to discharge the cold water.
All in all, Zero Cold Water isn't as perfect as you might think, but it's not useless either. Take a look at the above drawbacks, and if you are okay with them, you can decide whether you need a zero-chill water heater based on the following criteria:
Is the straight-line distance between the kitchen and bathroom more than 5 meters?
Isn't buying zero cold water to save money (water bills)?
Are you willing to pay extra for a better quality of life?
If the answer to all three of the above questions is "yes", then don't hesitate to go for Zero Cold Water. If the answer to any of them is "no", I recommend that you consult with users who have already used it and consider it carefully before making a decision.