Vacuum Drying Oven Not Reaching the Set Vacuum Level: Causes and Repair Service
Is your vacuum drying oven unable to reach the set pressure, taking too long to create vacuum, failing to reach deep vacuum, or losing vacuum shortly after operation?
This is a common issue in Vacuum Dryers, Vacuum Drying Ovens, laboratory vacuum ovens, and industrial vacuum drying ovens after long-term use.
When this problem occurs, the drying process is often prolonged, the product may not dry properly, drying temperature may become unstable, and the final batch quality can be directly affected.
Weak vacuum suction
Pressure drop during drying
Long drying time
Vacuum pump running continuously
VietSonic provides inspection, repair, and maintenance services for vacuum drying ovens that fail to reach the set vacuum level for businesses, factories, laboratories, pharmaceutical, food, chemical, material, and technical component manufacturing facilities.
Signs That a Vacuum Drying Oven Cannot Reach the Required Vacuum Level
Businesses should inspect the machine early if the vacuum drying oven shows the following symptoms:
The machine takes a long time to create vacuum but pressure does not decrease
The vacuum gauge or display shows that pressure decreases very slowly and cannot reach the set value required by the process.
The vacuum level is reached more slowly than usual
The machine used to create vacuum quickly, but now takes much longer to reach the same pressure level.
Pressure rises again during the drying process
The machine has already reached a vacuum level, but after a period of operation, the pressure rises again and the vacuum environment cannot remain stable.
The vacuum pump runs continuously
The pump operates continuously, but the drying chamber is still not sealed properly, causing the pump to overheat, consume more oil, and reduce equipment lifespan.
- The product takes a long time to dry and remains moist after the cycle ends.
- The oven reports pressure error, vacuum error, or failure to reach vacuum.
- There is a slight hissing sound at the door, valves, pipelines, or pump connection points.
- The vacuum pump becomes hot, makes loud noise, has weak suction, or produces abnormal oil smell.
Why Does a Vacuum Drying Oven Fail to Reach the Set Pressure?
Failure to reach the required vacuum level is not only caused by the vacuum pump. In actual repair cases, the cause may come from many different components in the system.
The oven door gasket is leaking, hardened, or deformed
The door gasket is a very important component for sealing the drying chamber. After long-term operation at high temperatures, the gasket may become hardened, cracked, flattened, swollen, or lose elasticity.
When the door gasket is no longer sealed properly, outside air will enter the drying chamber, causing the machine to run continuously without reaching the set vacuum level.
The oven door does not close tightly or the hinge is misaligned
In some cases, the machine cannot reach vacuum not because the gasket is completely damaged, but because the door does not close evenly, the hinge is misaligned, the door lock is worn, or the contact surface between the door and gasket is no longer tight.
A common sign is that the machine can still create vacuum, but the pressure does not go deep enough, or the vacuum reading changes when the door is lightly pressed.
The vacuum pipeline is leaking or the connectors are loose
The pipeline connecting the drying chamber to the vacuum pump may become cracked, aged, loose at clamps, leaking at threaded joints, or leaking at fitting connections.
This is a very common issue but is easily overlooked, especially in machines that have been relocated, had the pump replaced, had the hose replaced, or were previously disassembled for cleaning.
Vacuum valve, air release valve, or solenoid valve is leaking
If the valve does not close tightly, is stuck due to residue, has a damaged seal, or the valve coil operates unstably, air can enter the system.
In that case, even if the pump is still running normally, the drying chamber still cannot reach the required vacuum pressure.
The vacuum pump is weak, low on oil, or the pump oil is dirty
The vacuum pump is the component that directly creates negative pressure for the drying chamber. If the pump is weak, the oil is dirty, the oil level is low, the exhaust filter is clogged, the vanes are worn, or the motor performance has declined, suction capacity will decrease significantly.
- The pump is louder than usual.
- The pump heats up quickly.
- The pump oil changes color, becomes cloudy, or has an unusual smell.
- Vacuum creation is slow and pressure cannot go deep.
- There is oil smoke or oil vapor at the exhaust outlet.
Too much moisture or solvent inside the drying chamber
In some cases, the machine does not reach vacuum not because of an immediate mechanical failure, but because the product contains too much moisture, the solvent evaporates strongly, or the samples are arranged too densely.
When too much vapor is released, the vacuum pump must operate continuously and the chamber pressure becomes difficult to reduce quickly according to the set parameters.
The pressure sensor or vacuum gauge gives incorrect readings
In some cases, the drying chamber may still be able to create vacuum, but the pressure sensor or vacuum gauge gives incorrect readings due to calibration drift, moisture contamination, damaged signal wiring, or control board failure.
If the diagnosis is based only on the display without checking with an independent measuring device, it is very easy to identify the wrong cause.
How Does Failure to Reach Vacuum Affect the Drying Process?
When a vacuum drying oven cannot reach the set vacuum level, businesses may face many problems in production, testing, or material processing.
- Drying time becomes longer than usual.
- The product does not reach the required dryness.
- Batch quality becomes unstable.
- Temperature and pressure do not follow the required process.
- There is increased risk of vacuum pump damage due to continuous operation.
- Electricity consumption, pump oil consumption, and maintenance costs increase.
- Production or testing schedules may be affected.
For heat-sensitive products, pharmaceutical materials, chemicals, technical materials, or components that require drying in a stable vacuum environment, this issue should be handled early.
VietSonic Provides Repair Service for Vacuum Drying Ovens That Cannot Reach Vacuum
VietSonic provides inspection, repair, and maintenance services for Vacuum Dryer / Vacuum Drying Oven systems experiencing issues such as failure to reach the set pressure, weak suction, vacuum leakage, or ineffective drying.
Vacuum sealing system inspection
- Inspect drying chamber tightness.
- Inspect door gasket, hinge, and door lock.
- Inspect vacuum pipeline, fittings, and connectors.
- Inspect vacuum valve, air release valve, and solenoid valve.
Pump and control system inspection
- Inspect vacuum pump, pump oil, exhaust filter, and pump motor.
- Inspect vacuum gauge and pressure sensor.
- Inspect the control system related to pressure control.
- Run test and re-evaluate vacuum holding performance after repair.
VietSonic Inspection and Troubleshooting Process
Issue receiving
Record machine model, pressure condition, vacuum creation time, error messages, and actual operating symptoms.
Cause inspection
Evaluate door gasket, valves, pipelines, vacuum pump, sensors, and control system.
Repair and maintenance
Clean, adjust, replace suitable components, and fix leakage or sealing points.
Test run and handover
Recheck vacuum reaching capability, vacuum holding performance, and operating condition after repair.
When Should You Call a Technician for Inspection?
Businesses should request an inspection if the vacuum drying oven has any of the following conditions:
- The machine takes longer than usual to create vacuum.
- The set pressure cannot be reached.
- Pressure rises again after reaching vacuum.
- The vacuum pump runs continuously without stopping.
- The product does not dry even after increasing drying time.
- The door gasket shows signs of hardening, cracking, or leakage.
- The vacuum pump is noisy, hot, or the pump oil becomes dirty quickly.
- The machine reports vacuum error, pressure error, or drying process error.
Early inspection helps identify the correct cause, avoid replacing the wrong parts, and reduce prolonged machine downtime.
Service Suitable for Many Types of Vacuum Drying Ovens
Laboratory equipment
- Laboratory vacuum drying oven.
- Vacuum Drying Oven.
- Vacuum drying oven with automatic temperature and pressure control.
Production and industrial equipment
- Industrial vacuum drying oven.
- Vacuum Dryer.
- Vacuum drying system with separate vacuum pump.
- Vacuum drying oven used in pharmaceutical, food, chemical, and material industries.
Contact Us for Vacuum Drying Oven Repair
If your company’s vacuum drying oven is experiencing issues such as failure to reach the set vacuum level, weak suction, vacuum loss, long drying time, or abnormal vacuum pump operation, contact VietSonic for inspection and suitable repair consultation.
Phone: 0938 49 33 66 — Mr. Hải
Email: info.vietsonic@gmail.com
Website: vietsonic.vn