Is the zero cold water water heater for home use really as easy to use as advertised?

What should I do if the water heater is too far away from the bathroom and a lot of cold water needs to be discharged every time I take a shower? Why do the faucets in hotels produce hot water when you turn them on? These problems all have one device that cannot be avoided - the hot water circulation pump.

In the past, in order to make it more convenient to use hot water, we would add a hot water circulation pump next to the water heater. Well now, the water heater is directly integrated with the circulation pump, and we do not need to buy and install it separately. It is more convenient and better-looking - a gas water heater with an integrated hot water circulation pump is called a "zero cold water" gas water heater. Hot water circulation system

Every time you use water, you must first release some cold water because the hot water is in the water heater. After opening the faucet, the first thing released is the water in the pipe. Hot water will not appear until all the cold water in the pipe is drained. After turning off the faucet, the hot water remaining in the pipe will slowly cool down until it is released the next time the hot water is used.

The hot water circulation system empties the cold water in the pipes before we use water, so that the hot water can fill the pipes in advance. The method is actually simple, just pressurize the pipe directly to let the water flow. As for the cold water in the pipes, it is pushed back into the water heater for heating▼

The "misunderstanding" of the "zero cold water" gas water heater

The seemingly perfect hot water circulation system In fact, there are still many problems, otherwise it would not be recommended only for users who use water far away from the installation - the "zero cold water" gas water heater integrated with a hot water circulation pump faces the same problems as the hot water circulation pump.

These problems may not be imagined by many users, and it is easy for people to mistakenly think that it is good:

1. Unconditional installation?

How to return the water in the hot water pipe to the water heater is a problem - in the hot water circulation system, the following two solutions are often used▼

Among them The first method is the most ideal, but it requires a special return pipe to be reserved during decoration. If you miss the renovation, you will have to choose the second option.

In the second option, the return water needs to go back to the water heater through the cold water pipe. This means that the next time you open the cold water faucet, the water that flows out will be the water that has passed through the water heater - the water heater has been used for a long time, and there will be a lot of scale and bacteria in it. If you open the cold water faucet near the one-way valve, some hot water may be released first.

2. More energy-saving?

There is no need to release a lot of cold water before using hot water. Therefore, many people think that the hot water circulation system is more energy-saving. Actually not - although it doesn’t consume water, it consumes more electricity and gas.

During the water circulation process, the water pump needs to be started. Every time the water pump is started, it consumes a lot of electricity.

In the process of not using water, the water in the pipes is still circulating regularly. Every time it cycles, the water heater needs to be started to heat up - only in this way can the pipes be filled with hot water at all times.

Because of this, few people turn on the hot water circulation function 24 hours a day during use (yes, the "zero cold water" function can be turned off). Most users will choose to turn it on once before using water (if the water use time is fixed, it can be turned on regularly). If they are lazy users, they may not turn it on once all year round.

3. Zero cold water = full hot water?

Even if the hot water circulation function is turned on 24 hours a day, there is no guarantee that we will get the water temperature we want when we open the faucet.

This is because even if the hot water circulation function is turned on, the circulation pump will not always be on (it consumes too much power). It will automatically adjust the starting frequency according to the set temperature - when the water in the pipe is almost cold, it will cycle once.

When the circulation pump is not turned on, although the water in the pipe will not become cold water, it will definitely not reach the set temperature of the water heater.