Common Causes of a Water Dispenser Not Cooling
Today, we are repairing a Yamada 389-21-P water dispenser with a cooling failure issue. The customer reported that the water is not getting cold, which affects normal usage.
饮水机无法制冷的维修过程
今天我们来维修一台 Yamada 389-21-P 饮水机，客户反馈 饮水机无法制冷，导致无法提供冷水。
1️⃣ Initial Inspection – Confirming Cooling Failure
We first take a small cup of cold water and measure the temperature using a thermometer.
📌 Measured water temperature: 34°C – This is close to room temperature, indicating a cooling system failure.
1️⃣ 初步检查 – 确认制冷故障
我们首先取一小杯冷水，并使用温度计测量水温。
📌 测得水温：34°C，与常温接近，说明制冷功能失效。
2️⃣ Disassembly & Troubleshooting – Identifying the Problem
We proceed with the following steps to check the internal components:
🔹 Remove the filter cartridge and open the back cover to expose the cooling system.
🔹 Use a multimeter to measure the current – The reading is only 0.2A, which means that only the fan is running, but the cooling module is not working.
🔹 Test the Peltier cooling module (TEC12706) – The resistance reading is 23Ω, which is abnormal. This confirms that the thermoelectric cooling plate is faul
2️⃣ 拆机检查 – 发现制冷片损坏
我们按照以下步骤拆机检查：
🔹 取下滤芯，打开后盖，露出制冷系统组件。
🔹 使用万用表测量电流，发现 电流仅 0.2A，说明只有风扇在工作，制冷片可能失效。
🔹 测试半导体制冷片（TEC12706），测得 电阻为 23Ω，这并不正常，说明 制冷片已经损坏。
3️⃣ Understanding the Role of the Peltier Cooling Module
🟢 How the Peltier Module Works:
The TEC12706 thermoelectric cooling plate has two sides:
- One side absorbs heat (cold side) → This cools the water.
- The other side releases heat (hot side) → This requires a fan to dissipate heat.
🛑 Why Do Peltier Cooling Modules Fail?
✔ Cooling fan failure – Poor heat dissipation causes overheating, damaging the module.
✔ Power supply issues – Voltage fluctuations or unstable power can burn out the cooling plate.
✔ Prolonged use without maintenance – Dust buildup reduces cooling efficiency.
3️⃣ 了解半导体制冷片的工作原理
🟢 制冷片的作用：
半导体制冷片（TEC12706）工作时，一面制冷（贴近水箱），另一面发热（贴近散热器）。
如果风扇故障，无法散热，会导致制冷片过热损坏。
🛑 制冷片损坏的常见原因：
✔ 风扇老化，散热不良，导致温度过高，损坏制冷片。
✔ 电源供应异常，导致制冷片过载。
✔ 长期运行无维护，积尘影响散热效果。
4️⃣ Replacing the Cooling Module & Fan
To restore the cooling function, we replace both the Peltier cooling plate and the fan.
🔹 Choosing the Right Cooling Plate (TEC12706):
✅ Original High-Power TEC12706 – Faster and more efficient cooling.
❌ Low-Power TEC12706 – Slower cooling, lower efficiency.
To ensure optimal performance, we install the original high-power TEC12706 SR module.
🔹 Replacing the Fan:
Since the 12V DC cooling fan is aging, we also replace it to improve heat dissipation and prevent further issues.
4️⃣ 更换制冷片 & 风扇
为了确保修复效果，我们决定 更换制冷片和风扇。
🔹 选择制冷片：
市面上的 TEC12706 制冷片有两种：
✅ 原装款 – 制冷速度快，功率高，效率好。
❌ 低功率款 – 价格低，但制冷慢，性能较差。
我们选择 原装款 TEC12706 SR，保证最佳制冷效果。
🔹 更换风扇：
风扇老化会影响散热，导致制冷效果下降，因此我们更换 12V 直流散热风扇。
5️⃣ Final Testing & System Verification
After installing the new components, we conduct several tests:
✅ Current measurement – The new Peltier is 0Ω, module draws 3.11A, indicating normal operation.
✅ Total power consumption – Measured at 45.89W, within expected performance range.
✅ Heat dissipation check – The back cooling fan temperature is 37.7°C, confirming proper heat dissipation.
🔹 Finally, we reassemble the back cover and filter cartridge.
🔹 Cooling performance will improve gradually within 1 hour as the Peltier module lowers the water temperature.
5️⃣ 维修完成 & 测试效果
🛠 安装新制冷片 & 风扇后，进行以下测试：
✅ 测量组织和电流：新制冷片电阻为0Ω，工作时，电流恢复至 3.11A，说明已正常运作。
✅ 测量总功率：总功率 45.89W，符合设备正常运行标准。
✅ 检查散热温度：散热风扇温度 37.7°C，说明风扇在正常散热。
🔹 最后装回后盖 & 滤芯，等待 1 小时测试冷水效果。
6️⃣ Repair Summary – Restoring Proper Cooling Function
After replacing the Peltier cooling module and fan, the Yamada 389-21-P water dispenser is back to normal operation.
6️⃣ 维修总结 – 确保饮水机恢复制冷功能
经过维修，Yamada 389-21-P 饮水机的制冷功能已恢复，预计 1 小时内水温会逐步下降，恢复正常冷水供应。
💡 Maintenance Tips to Prevent Cooling Failure
✔ Regularly clean the cooling fan to prevent dust buildup and overheating.
✔ Check power stability to avoid damage to the cooling system.
✔ If cooling efficiency drops, inspect the Peltier module early to prevent further damage.
If your water dispenser is not cooling, cooling slowly, has a faulty cooling module, or a malfunctioning fan, feel free to contact us! We offer professional water dispenser repair services to keep your unit running perfectly. 🚰❄
💡 维护建议
✔ 定期清洁散热风扇，防止积尘影响散热。
✔ 检查电源电压是否稳定，避免损坏制冷片。
✔ 发现冷水温度异常，应尽早检查维修，防止损坏进一步加重。
如果您的 饮水机无法制冷、制冷速度慢、制冷片损坏、风扇故障，欢迎联系我们，我们提供 专业饮水机维修服务，让您的设备恢复最佳状态！ 🚰❄