1. Recognizing Signs of Leakage in Dai Thanh Core 215l (58-21) Solar Water Heater
To identify if your Dai Thanh Core 215l (58-21) solar water heater is leaking, look for the following signs:
- Water leakage from water pipes on the roof indicates an issue in the rooftop system where the water heater is installed.
- Water flowing from the glass tube and insulated tank.
- The solar thermal bath tank automatically pumps water while your home uses less water, or the water pumping speed takes longer than usual.

2. Causes and Solutions for Dai Thanh Core 215l (58-21) Solar Water Heater Leakage
Explore common reasons and solutions for leakage in Dai Thanh Core 215l (58-21) solar water heaters:
2.1. Case of torn or misaligned rubber gasket
The first cause may be due to the rubber gasket of the water heater being torn or misaligned due to prolonged use. Especially, it may have been contaminated with substances such as lime, sediment, salt, etc. During use, the rubber gasket is prone to tearing. Additionally, it can be affected by factors like less rain, intense sunlight, or strong storms.

Solution: First, carefully inspect the damaged and leaking areas such as the tank body, steam pipe, water inlet, or areas in contact with the glass tube. Once you identify the leaking spot, purchase a new rubber gasket for replacement.
2.2. Cracks in the insulated tank on both sides
The second cause may be cracks on both sides of the insulated tank or uneven welds, causing water to leak inside.
Solution: Open the insulated tank cover, use insulation foam to attach and seal the lid. Once the crack is sealed, you can resume normal use. If the insulation foam stops the water from leaking, it's a success. If the water still leaks, replace the insulated tank and contact the technical department for assistance.
2.3. Punctured Insulated Tank
The next cause is a punctured insulated tank, as prolonged use can corrode the tank lining. Additionally, poor quality of the insulated tank may make it susceptible to contaminants such as lime, salt, causing the water heater to leak.
Solution: If your Dai Thanh Core 215l (58-21) solar water heater faces this issue, the only solution is to replace the insulated tank. During installation, carefully research the necessary equipment to ensure it won't puncture. Additionally, consider installing a sediment filter for cleaner water output.

2.4. Vacuum Tube Breakage
This is also a common cause of water leakage. External factors or forceful opening of the water valve can lead to the breakage of the vacuum tube, causing water to leak.
Solution: Replace the vacuum tube. If the inner tube is unaffected, replace the gasket and tighten the tube connection.
Here is a compilation of causes and solutions for leaks in Dai Thanh Core 215l (58-21) solar water heaters. If you find it helpful, don't forget to save and apply it right away!
