A vacuum pump that runs too hot is usually suffering from poor ventilation, low or degraded oil, running continuously against a leak, a blocked inlet or exhaust filter, high ambient temperature, or electrical overload. Overheating shortens pump life fast, so it’s worth diagnosing quickly.
1. Poor ventilation or a dirty cooling fan
Oil-sealed and dry pumps shed heat through a fan and cooling fins. Blocked fins, a clogged fan guard or a pump boxed into a cabinet with no airflow will cause overheating. Clean the fins and give the pump room to breathe.
2. Low or degraded oil
Oil cools as well as seals. Low, old or wrong-grade oil runs hot – check the oil first.
3. Running against a leak
A pump working continuously at high pressure because of a leak does more work and gets hotter. Fix the leak.
4. Blocked filters
A clogged inlet filter or restricted exhaust makes the pump work harder and heat up. Check and replace filters.
5. High ambient temperature or overload
Hot rooms, high duty cycles or an electrical fault can trip the thermal protector. Improve cooling, and if the motor is drawing high current, have it checked.
Pump running too hot?
Overheating causes fast wear – send us the model and symptoms and we’ll advise before it fails. Email [email protected] or request a quote.
Frequently asked questions
Why does my vacuum pump get so hot?
Common causes are poor ventilation or dirty cooling fins, low or degraded oil, running continuously against a leak, blocked filters, high ambient temperature or electrical overload.
Is it normal for a vacuum pump to be hot?
Vacuum pumps run warm in normal use, but if it is too hot to touch, is tripping the thermal cut-out or smells of hot oil, something is wrong – check ventilation and oil first.
Can overheating damage a vacuum pump?
Yes. Overheating degrades the oil, accelerates wear on vanes, seals and bearings, and can cause the motor to fail. Fix the cause promptly to avoid a major repair.
Written by the Girovac technical team. Girovac Ltd has supplied and serviced industrial and laboratory vacuum equipment from its North Walsham workshop since 1983. Last updated: July 2026.