When buying second-hand home appliances, you cannot skip the steps of machine inspection.

The second-hand home appliance market is riskier than second-hand mobile phones - problems with home appliances are often deeper hidden, making it harder for sellers to be held accountable. Unlike mobile phones, which can quickly run tests, the power-on test scenarios for major appliances are limited, and the inspection needs to be targeted.

General machine inspection principles

1. Offline machine inspection is better than online

Pictures and videos cannot be checked, and there are many hidden problems. When conditions permit, sight trading is the basic principle.

2. Power-on test is a must

When trading second-hand home appliances, any commitment without a power test is meaningless.

3. Query serial number

The serial numbers of major home appliances can be found on the manufacturer’s official website:

Production date (to determine the actual age of the device)
Warranty status (whether it is still under warranty)
Whether it is a parallel import/refurbished/repaired machine

Refrigerator inspection list

Appearance inspection:

Whether the door seal (rubber seal) is intact and whether it is torn or deformed?
Door seal test: Clamp a piece of A4 paper in the door gap and close the door. There should be obvious resistance when pulling the paper (indicating good sealing)
Is there any obvious odor inside (musty odor that is difficult to remove is a big problem)
Are there any dents or cracks on the inner wall of the refrigerator?

Power on test:

Turn on the machine for 10–15 minutes and listen to the compressor sound: regular low-frequency buzzing is normal; abnormal noises and shaking sounds are abnormal.
Freezer: Check whether it can make ice/reach low temperature (use a thermometer, normal should be below -15°C)
Refrigerator: should be at 2–8°C after normal operation

Special to air-cooled refrigerators:

Open the freezer and check whether there is ice accumulation (a large amount of ice accumulation indicates that the automatic defrost function may be malfunctioning)

Washing Machine Inspection Checklist

Appearance inspection:

Is there any rust on the inner cylinder (rust spots on the stainless steel inner cylinder are a problem)
Is the sealing ring (not on the impeller, but on the roller) intact?
Whether the drainage pipe is complete, whether it is creased or hardened

Power on test:

Run a washing cycle (at least go through filling → washing → dehydration)
The degree of shaking during dehydration: moderate vibration is normal; severe shaking or movement indicates damage to the counterweight/shock absorber failure.
Is drainage smooth (drainage pump is operating normally)

Special to drum washing machines:

Check if there is mold on the inside of the sealing ring (severe mold is difficult to completely remove)
Is there any cracks in the door glass?

Air conditioner inspection list

Appearance inspection:

Internal filter (visible when disassembled): serious dust accumulation, mold, and odor require professional cleaning (additional cost)
Condensate water pipeline: it should be directed downwards to avoid water leakage
Are there any damage to the drain outlet and the connecting pipe of the outdoor unit?

Power-on test (cooling mode):

Set 16°C cooling and check the air outlet temperature after 10 minutes (normally it should be 6–10°C lower than room temperature)
Sound when the compressor starts: Uniform operating sound is normal; abnormal noise and large vibration need attention
Whether the indoor unit is leaking: Check the bottom of the indoor unit after running for a long time

Heating mode (if available):

Also set the high temperature and detect whether there is warm air from the air outlet
Note: It is necessary to check the heating of the machine in winter and the cooling of the machine in summer.

Dishwasher inspection list

Appearance inspection:

Are there any signs of corrosion or obvious collision dents on the inner cavity wall?
Whether the spray arm can rotate freely (toggle it by hand)
Condition of sealing strip (rubber seal on door edge)

Power on test:

Run a wash program (run with water)
Check: whether the water inflow is normal; whether the heating is working (put your hand in to feel the heat of the outlet water); whether the drainage is complete

Water heater inspection list

Focus on age:

The recommended service life of storage-type electric water heater is 8 years
Water heaters that are more than 10 years old have a high risk of inner tank corrosion and are not recommended for purchase.

Things to check:

Check the production date (usually affixed to the fuselage label)
Confirm whether there are records of repair/replacement of safety valves
After turning on water and power, check: whether there is slight dripping from the safety valve (normal) or a large amount of water (safety valve failure)
Check the electrical parts for signs of scorch

Price judgment reference

Reasonable transaction price of second-hand home appliances, rough reference:

Useful life	Depreciation reference
Less than 1 year	70–80% of original price
2–3 years	50–65% of original price
4–5 years	30–50% of original price
6–8 years	20–35% of original price
More than 8 years old	Original price < 20%, buy with caution

Note: The shipping fee for major appliances is not low (200-400 yuan in the city). However, if the machine is inspected, it will need to be returned and transported, which is very costly → I would rather spend a little more to buy something in good condition.

High-risk categories (caution recommended)

The following categories have higher second-hand risks:

Top-type washing machine: The bearings are worn, the shock absorber is damaged, the noise is huge but the appearance is not visible.
Air Conditioning: Refrigerant missing (usually refrigerant leakage) appearance cannot be judged
Water heater (more than 6 years old): Inner tank corrosion cannot be judged by appearance

*This article refers to the national safety regulations for home appliance repair services and consumer association complaint data, and does not target specific brands. *