Vacuum Furnace Preventive Maintenance: Semiannual Checklist


Extending the life of your vacuum furnace through preventive maintenance will result in decreased downtime and increased productivity.

In previous posts, we discussed some of the maintenance tasks that should be performed daily, weekly and monthly. Now, we conclude our preventive maintenance series with our semiannual checklist.

Every Three Months

Variable Reactance Transformers (VRT)

⬜ Inspect all VRT resistors.

⬜ Inspect secondary power cables to the VRT for wear.

⬜ Ensure that all cables to and from the VRT have tight connections.

Voltage & Amperage

⬜ Inspect the setting of the blower blast gate to avoid exceeding motor amperage ratings (applicable for Ipsen MetalMaster/HR models).

Wiring & Fuses

⬜ Inspect the wiring on all cabinets and junction boxes.

⬜ Inspect all fuses for continuity.

Bottom-Head Alignment

⬜ Inspect bottom-head or door alignment to tank flange.

⬜ Ensure that the bottom-head motor and the gearbox shafts are aligned.


⬜ Test control and overtemperature thermocouples for proper response and direction.

Every Six Months


⬜ Replace load thermocouples regardless of appearance. If the vacuum-indicating instrument shows a possible malfunction in the sensing head, apply corrective actions and replace the vacuum-sensing head.

  • NOTE: Keep spare sensing heads on hand at all times.

Controls System

⬜ If you have a paper chart recorder, clean and lubricate the chart drive mechanics and slide-wire mechanism.

  • NOTE: This step is only applicable if you have an older furnace as newer ones are mostly digital.

⬜ Check the temperature, calibration and stability on your test instruments.

If you need further assistance, please contact Ipsen at 1-844-GO-IPSEN.

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