Why Autoclave Keeps Switching On and Off

autoclave attacca e stacca

Why Autoclave Keeps Switching On and Off

When an autoclave keeps switching on and off, it indicates that there is a problem in the system, not necessarily with the pump, but with everything else surrounding it. If the electric pump is running, it means it is functioning, and if it keeps switching on and off, it means everything is working. The on and off cycle is the normal operation of the autoclave. This happens every time water is drawn from the system. So, if this continuous switching on and off is not desired, it is necessary to identify the cause.

If there is no intentional water draw, then it is caused by some leakage in the system. Another cause could be the check valve. What is a check valve? This valve allows water to flow in one direction only. Think of a balloon, when we blow it, it inflates, and if we stop without closing it, the air escapes. The same thing happens with water and the valve. Water enters the system due to the motor, and as soon as the motor stops, the valve does not allow the water to flow back.

Researching the Causes of Autoclave Switching On and Off


One of the reasons for autoclave switching on and off could be the malfunctioning of this valve. The pump is activated, it pumps water into the system, and if the tap is closed, it stops. If the valve does not function properly, it flows back, and the motor restarts. This triggers an infinite loop, and the cycle continues uninterrupted. When the motor pushes water and there is no ongoing water draw, the autoclave switches off.

Read also: How does an autoclave work and how to install it


If the check valve does not function properly, it allows the water to flow downwards, emptying the system. The autoclave detects this action as a tap opening because the pressure in the system has dropped, and it activates the motor. This is a possible cause for the autoclave switching on and off.

In this case, it needs to be disassembled and replaced.

Another common cause that leads to the autoclave switching on and off is the toilet cistern. Many times, its leakage is not easily detectable unless carefully checked. To notice if it is leaking, you need to look inside the toilet. Pay close attention to the water inside. It is nearly impossible to see a thin stream of water flowing along the white ceramic, but there is a trick.

Carefully observe the water’s surface and notice if there is a slight disturbance. Alternatively, dry the ceramic with a piece of paper and, using the same paper, check if it is wet. This method is foolproof, and one needs to be very attentive as it is difficult to detect.

autoclave keeps switching on and off toilet leakage


In this image, the blue line indicates where the invisible water stream flows. The area enclosed within the orange borders of the rectangle is the part that needs to be dried and checked with the paper. This is a leak that can cause the autoclave to switch on every 10 minutes.

The causes of this water flow inside the toilet are generally two:
1) The seal on the plunger in the wall-mounted cistern or the one where the closing ball rests, usually in a built-in cistern like Pucci.

2) The overflow, which is managed similarly in both types of cisterns.

In the first case, it could be due to wear and tear of the seal or due to limescale or residue at the bottom of the cistern. Residues in the water form due to piping or poor tank cleaning. You know those residues you find in faucet filters that clog the water outlet? They are the ones. Usually, when water is unavailable or turned off in condominiums, all kinds of things end up in the pipes. Especially rust.

Limescale is the other common enemy. It attaches to the seal, plunger, or closing ball, creating a gap where water passes through. In both cases, simply cleaning or replacing the seal solves the problem. And cleaning the tank from the residues.

In the case of the overflow, the float must be adjusted properly or the seal must be replaced. The seal is found in the plunger that closes the water passage. Here is a detailed guide on how to replace the float valve seal.

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Another cause could be a possible leakage causing a decrease in pressure in the system, triggering the activation of the water pump. If it is not visible at a specific point, the search needs to be done by excluding areas one by one. Even a small faucet leak can be the cause. Many times, a simple drip is enough to activate the pump, even if it takes longer.

I mean, if the switching on and off occurs quickly, it means the leak is significant. A drip would take about 10 minutes before triggering the pump.

Autoclave Switching On and Off: Searching for Potential Leaks
If some sectors are separated by shut-offs, for example, by control panels serving separate areas, you can exclude leaks by excluding zones individually. By excluding each zone separately, you can identify where the leak is present. But first, check if the valves are working correctly.

If there is a control panel with shut-offs for individual water points, you can close the valves one by one. As you can see in the photo, each valve controls a pipe that supplies water to each individual fixture. The blue ones are for cold water, and the red ones are for hot water. By initially closing the valve that feeds the control panel, you exclude all its calls. Then, starting from there, exclude all the hot or cold water calls one by one. If you identify the type of water and discover the leak, then start closing the faucets one by one to understand which one is leaking.

This method allows for a detailed inspection of sectors to narrow down the search area for the leak.

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