Common Quality Issues in Water Purifier Manufacturing

Why Some Factories Produce Unstable Batches — A Manufacturer’s Perspective

In the water purifier industry, many wholesalers and brand owners face the same frustrating problem:
the same model from the same factory shows different quality issues in different production batches.

Some batches leak, some have control failures, others show abnormal wastewater discharge or water shortage alarms.
These issues not only increase after-sales costs, but also seriously damage brand reputation.

So where do these problems really come from?
In this article, we analyze common quality issues in water purifier production from the factory side, helping wholesalers and OEM/ODM partners understand the real causes behind product instability.

1. Unstable Raw Materials — The Root Cause of Batch Quality Problems

Under intense market competition, some manufacturers focus only on price wars and cost reduction.
To win orders, they frequently change suppliers, which directly leads to unstable product quality.

Common problems caused by unstable raw materials

• Inconsistent performance between batches
• Increased pump noise or reduced lifespan
• Higher failure rates of solenoid valves and fittings
• Dimensional deviations in plastic parts leading to water leakage

Why this happens

• Suppliers are changed too frequently
• Purchasing decisions are based on price, not stability
• Incoming materials are not properly inspected

What professional factories do

• Select long-term, reliable core suppliers
• Avoid changing suppliers casually due to price fluctuations
• Require inspection reports for every material batch
• Conduct incoming quality inspections by sampling ratio
• Provide feedback and corrective actions when issues occur

For a factory, product quality must come before low prices.
Only stable quality can attract long-term customers and sustainable growth.

2. Common Problems During the Assembly Process

2.1 Water Leakage — The Most Frequent and Serious Issue

Water leakage is one of the most common complaints in water purifiers, especially during winter.

Typical causes

• Tubes become harder in cold weather and are not fully inserted
• Tube cutters are dull, resulting in uneven tube ends
• Tubes are bent during installation
• O-rings are missing or incorrectly positioned

These small assembly mistakes often lead to leakage after installation or long-term use.

How professional factories prevent leakage

• Standardized tube cutting procedures
• Regular replacement of cutting tools
• Clear insertion depth requirements
• Mandatory water pressure testing for critical connections

2.2 “No Water” Alarm After Installation

This is another common issue reported by wholesalers.

Main reasons

• Wiring connectors not fully plugged in
• Connectors loosened during transportation
• No secondary check after installation

Correct practice

• Plug-and-unplug confirmation during testing
• Full inspection of wiring connections before shipment
• Functional testing under real working conditions

2.3 Continuous Wastewater Discharge After Tank Is Full

Common causes

• Inlet solenoid valve installed in the wrong direction
• Check valve installed incorrectly
• Assembly staff lack understanding of water flow principles

Key solutions

• Clear direction markings for solenoid and check valves
• Training workers on water circuit principles
• Anti-mistake (poka-yoke) design at critical assembly points

2.4 Insufficient Training Leads to Human Errors

Many quality issues are not caused by defective components, but by human errors.

When operators do not understand how a water purifier works, they may:

• Install components in the wrong direction
• Miss critical details
• Perform testing as a formality

Systematic training for new employees is essential for product stability.

3. Inadequate Testing Allows Problems to Reach the Market

After assembly, testing is the most critical step, yet it is often simplified or skipped by low-cost manufacturers.

Essential tests for every water purifier

• Water flow test
• TDS value testing
• Pure water output testing
• Wastewater ratio testing
• Pressure holding (shut-off) test
• Low-pressure start-up test

These tests verify whether:

• The unit is functioning correctly
• The water and electrical systems are stable and coordinated

If a unit is not properly tested, the problem will eventually be discovered by the end user.

4. Conclusion: Stability Comes from Systems, Not Luck

Water purifiers are not products that can succeed by low prices alone.
They involve water circuits, electrical systems, control logic, and long-term operational stability.

For wholesalers and brand owners, choosing a factory is essentially choosing:

• Raw material management capability
• Standardized manufacturing processes
• Complete testing procedures
• Training systems and responsibility awareness

Only when raw materials, production, and testing are strictly controlled can a factory deliver consistent quality across all batches.