Common Problems and Solutions with Autoclaves

Historically the terms autoclave and steam sterilizer have been interchangeable. But the terms are now often used in separate instances to differentiate the smaller table top units often used in labs, dental offices and clinics (autoclaves) and the larger units used in hospital sterile processing departments (sterilizers). While both use steam to kill microbial life that may be present on medical devices or instruments, the methods they use to achieve this are different so this post will deal primarily with the smaller autoclaves from manufacturers like Ritter-Midmark, Tuttnauer, and Pelton and Crane. Our biomedical service technicians know that the autoclave is an essential part of your business and with proper maintenance and cleaning you can extend the life of your autoclave.

Steps the autoclave goes through while operating

1. Items to be sterilized are prepared and placed inside the chamber and the door is closed and sealed.
2. A cycle is selected and water is introduced into the bottom of the chamber.
3. Heating elements either inside or outside the chamber begin turning the water to steam
4. As pressure and temperature set points are achieved within the chamber, the sterilization process begins.
5. A timer begins to count down the sterilization time based on the cycle chosen. As long as the autoclave stays within the temperature and pressure set points for the duration of the sterile cycle upon completion the cycle is considered successful. 

Unlike the larger sterilizers, autoclaves have a very simple system that is used to create and control the steam inside the chamber. The particulars will change slightly between models and manufacturers, but below is a list of devices that are standard for every autoclave and their function:

Control devices that are utilized within the autoclave

• Primary Control: This is the electrical or mechanical “brains” of the unit. It controls the time, pressure and temperature set points for the autoclave as well as the valves and alarms.
• Heating Element: This is the device, located either internal or external to the chamber based on manufacturer, that converts the water in the chamber to steam.
• Door Gasket: This device seals the door, keeping pressure from escaping and allowing pressure and temperature setpoints to be reached.
• Inlet and Outlet Valves: These devices control the water inlet to the chamber as well as the exhaust of water and steam back to the pure water holding tank. This system includes the bellows which allow excess moisture to escape the chamber during sterilization.
• Pressure and Temperature Sensors/Gauges: These devices, either analog or digital, allow the user to monitor current conditions inside the chamber. 
• Safety valve: This device is a safety measure that will release excess pressure from the chamber if that pressure gets beyond the manufacturer’s safety set points.

Common problems and solutions

• My autoclave is not turning on
• My autoclave is not fully pressurizing
• My autoclave is taking longer than normal to dry

My autoclave is not turning on

If your autoclave will not turn on, you will almost always find the problem in the power supply. The most common cause will be the outlet that the autoclave is plugged into. Current building code states that autoclaves need to be plugged into GFCI (ground fault current interrupt) outlets that have a resettable breaker built into them to cut power if there is a sufficient fluctuation in the amperage or the ground. Check the outlet to make sure that that relay hasn’t been tripped and reset it. If that doesn’t solve the problem, there may be an issue with the autoclave itself. Call ERD’s certified biomedical technicians to request an onsite diagnostic. 

My autoclave is not fully pressurizing

A pressure issue in your autoclave will have one of two causes. Either the autoclave isn’t able to build sufficient pressure in the chamber to hit its setpoints (a water supply or heating element problem) or the pressure is escaping the chamber before it can build to setpoint (a bellows or door gasket problem). A quick call to ERD’s certified biomedical technicians can help you troubleshoot the most likely cause and get your autoclave back up and running.

My autoclave is taking longer than normal to dry

If you notice your sterile cycles are completing successfully but your packs are coming out wet or that there’s a lot of excess steam or water at the end of the load you most likely have an issue with your bellows. The bellows allows excess moisture to return to the clean water chamber during the sterilization cycle and if it fails in a closed state that moisture isn’t allowed to escape, causing your packs or instruments to stay wet. Bellows are part of every PM, so if yours hasn’t been completed yet call ERD for a preventive maintenance quote.

Preventive maintenance of your autoclave is crucial to keep your sterilization department up and running smoothly. If you need to schedule preventative or curative autoclave maintenance service call ERD certified biomedical technicians today. We look forward to working with you.