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1. How do you tell a good solar water heater from inferior ones?
A solar water heater consists of three parts: heat-collection, heat-storage, and the bracket.
The quality of the heat-collecting part is controlled by the absorbing ratio and radiating ratio of the device. This is dependent upon the materials used and processing techniques. Kaisundun has a team of skilled technicians, so we can guarantee the quality of our product.
The heat-storing refers to the storage part of the solar water heater. There are three indicators of its quality. First is it is leaking or not? Next is the quality of the welding, which includes the welding method used for the interior tank, the strength of the welding, and whether the material used is anticorrosive. Lastly is the insulation layer. It dictates how long the solar water heater can keep water warm. In cold regions, a thicker insulation layer is needed.
The bracket supports the structure, and keeps the heat-collecting components in the correct position. It must be as durable, strong, and anticorrosive. Its quality can be ascertained by an examination of the material used, its thickness, and the surface finish.

2. How does an evacuated tube solar water heater work?

The solar water heater gathers heat and then stores it in a tank. The heat collector has a specialized coating on the interior of the tube which absorbs energy from the sun and transforms it into heat, thus heating the water in the tube. The hot water in the tube moves upward due to its lower density, and the cold water in the tank flows downward. Thus, the water in the tank circulates and the temperature continuously rises.

3. Why is the Kaidun Solar Water Heater more expensive than other brands?
The price of a product depends on several factors, such as the materials used, how it is made, and more. It is our practice at Kaisundun to use only materials that meet our strict quality standards. Using high quality materials which are processed skillfully and with advanced techniques makes Kaidun products durable, reliable, and long lasting.

4. What is the advantage of a solar water heater over other heaters?

A solar water heater is a long-term investment. Although it is more expensive than an electric heater or gas heater to purchase, that investment is the only one you make. What's more, it is reliable, safe, and no manual operation is needed. Taking everything into consideration, the solar water heater actually costs less. Consumers using an electric heater or a gas heater continue to pay for each shower they take.

5. What are the advantages in quality that Kaidun products have?
A quality evacuated tube is the key parts of a solar water heater. Kaidun uses only first-class evacuated tubes that are highly absorptive and resistant to hot and cold weather conditions. Our interior tank is made of a SUS304 stainless steel sheet, the insulation layer is made of foaming polyurethane, and the bracket is made of aluminum alloy sheet or stainless steel sheet, so each piece provides excellent performance.

6. When should you put water into a solar water heater?
As the temperature inside the evacuated tube can reach as high as 270℃ when empty under the sun, the initial input of water into an empty tank should be carried out 2 hours before sunrise or 2 hours after sunset.

7. How can I use a solar water heater if there is no tap water?
If you want to use a solar water heater in areas without tap water, a pump can be used to fill it with water. In addition, an extra water tank which stands the same height as the solar water heater to store cold water can also be used, so that cold water can be combined with the hot water from the solar water heater. (Please note: if you want to put water into the solar water heater, then the extra tank should stand higher than the solar water heater.)

8. How can you use a solar water heater in an area with a fixed water-releasing place?
If you want to use solar water heater in area with fixed water-releasing place, you could install a water tank with ball cocks to connect with the input and output openings, the water tank should stands at the same height as the solar water heater. Then when there is water, the tank will input water automatically, and you can also use the cold water to mix with the hot water.

9. How can you use a solar water heater on cloudy or rainy days?
The Kaidun solar water heater installs an auxiliary electric heating system which you can plug in 5 to 10 hours before use on cloudy or rainy days to heat the water in the tank. It is advisable to input the amount of water you need so as to save electricity.

10. What are the important points to using a solar water heater?
A. You should note the time to input water.
B. The amount of water to input depends on the weather conditions.
C. Check the pipeline and vent hole periodically.
D. In areas with heavy pollution, heavy sand storms or drought areas, please wash the evacuated tubes periodically.
E. After installation, only a professional should move or disassemble the heater.
F. Before using hot water, the power supply of the auxiliary electric heater should be cut off.
G. The auxiliary electric heater should be unplugged on stormy days or during a long period of not being used.

11. How to tell that the water in the solar water heater is fully filled?
Usually there is an overflowing pipe. If there is water running out of the pipe, the tank is fully filled. Also, you could install a waterline controller, which will alert you when the tank is full.

12. How to protect the evacuated tubes?
A. As the evacuated tubes are made of glass, they are easy to break. Please do not strike or impact them with force.
B. The vacuum of the evacuated tubes determines the heat-preserving capability, so please be careful with the sharp tip of the tubes.
C. The inner walls of the tubes are coated with a special material to absorb heat, please do not brush or scratch it. To get rid of fur, you can add an acid liquid and water and swag it to dissolve.

13. What should happen when using the electric heater?
A. Do not use the electric heater when there is no water in the tank.
B. Please unplug the creepage protection plug when it is not in use.
C. Check the reliability of the creepage protection plug before use.
D. If the creepage protection plug is damaged, you should not use a common plug to change it.

14. How to tell whether an evacuated tube is good or not?
A. A good evacuated tube should have intact mirror end.
B. The coating of the tube should have a nice color and no peeling, no serious scratches.
C. The sharp tip should be intact.
D. If the upper end breaks evenly, it is a faulty one.
E. If there are some tiny scratches on the coating of the inner tube, they are caused by the tip spring getter, it is not a flaw.

15. If there is already a gas or electric heater, can I install a solar heater also?
Yes. The solar water heater has a larger hot water output, so it can provide hot water for more purposes, such as washing hands, washing vegetables, clothes, etc. With the help of solar water, the working life of a gas or electric heater will be lengthened, and their safety will be improved. To install a solar water heater, an independent pipeline is needed.

16. How long is the guarantee period of your product?
The main part of our product is guaranteed for 3 years, the auxiliaries are guaranteed for 1 year.

17. What does the main part include? What do the auxiliaries include?
The main part includes the water tank, the bracket, and evacuated tubes. The auxiliaries include the electric heater, sensors, waterline, water temperature controllers, etc.

18. What if the solar water heater breaks after the guarantee period?
The main part of our product is guaranteed for 2 years, the auxiliaries are guaranteed for 1 year. Maintenance service is available for all of it throughout the working life. After the guarantee period, we will continue to provide service for a charge.

19. Will the user need to pay for maintenance service during the guarantee period?
During the guarantee period, if the solar water heater breaks due to a quality problem, there is no charge for the material, spare parts and service. If the problem was caused by improper use, the user is responsible for the material cost.

20. How to use a solar water heater?
It is very easy to use a solar water heater. You will find detailed instructions in the user's manual. Our professionals will also give you a demonstration.

21. Is the installation free?
Kaidun products are installed free of charge.

22. What are the usual methods to prevent freezing on a solar water heater?
A. Put on a thicker insulation layer.
B. Use an electric band heater.
C. Built-in heating wires.
D. Special pipelines with heat-absorbing surface coating to melt ice.
E. Empty the water in the pipelines.

23. What parts of the solar water heater should be carefully dealt with to prevent freezing?
A. The vent holes.
B. The elbow or turnings.
C. The joints of the pipelines.
D. The joints on the wall. In a word, all the pipelines outdoor should be carefully dealt with to prevent freezing.

24. What are the components of a Solar Water Heater?
Basically, a solar water heater is composed of a solar collector, water tank, bracket and some auxiliary parts.

25. What are the advantages of a solar water heater?
There are five advantages:
1. Solar energy is inexhaustible in supply and is always available for use.
2. It is economical. Nowadays, the prices of gas and electricity are getting higher and higher, but we can get solar energy from the sun for free.
3. It can be co-operated with a back-up such as a gas or electric heater to make the heater work year-round, even in bad weather.
4. It is a kind of new green energy. No pollution and very safe.
5. It has a long life and can be used over 15 years.

26. How many years do you guarantee your products?
We guarantee the solar water heater for 3 years and the spare parts for 1 year. But their service life normally can exceed 15 years with proper operation.

27. What size solar water heater do I need?
For household use, one person needs about 50 liters of hot water for showering daily. For example, if there are 3 persons in one family, you need a 150 liter solar water heater. For hot water in the kitchen, another 50 liters should be added.

28. What's the temperature of the water we can get by using your solar water heaters?
On normal sunny days, with 8 hours of fair sunshine, you can get at least 85℃ hot water. In the summer time, the water can easily boil.