![eutron elements eutron elements](https://is1.ecplaza.com/Q6MLnL1pXnif57x1KfbQDSgpUoE=/fit-in/400x400/filters:fill(white,1)/is2.ecplaza.com/ecplaza2/products/2/2d/2d2/741283539/led-customer-display.jpg)
Easy to fix once you know what causes it, but not the most obvious thing to check at first.Thanks heaps for that, that makes more sense now. In Synessos the probes go into the boiler horizontally at one end, so sometimes the safety probe (being completely immersed) builds up enough scale to insulate it, the electronics freak out thinking the water is too low and kill power to the steam boiler element, and the machine suddenly loses pressure.
![eutron elements eutron elements](https://i.ytimg.com/vi/8YBHgodhCHM/maxresdefault.jpg)
![eutron elements eutron elements](https://media.cheggcdn.com/media%2F06d%2F06dd631d-36d2-4bc7-bff3-299658b8dac7%2Fimage.png)
![eutron elements eutron elements](https://dt7v1i9vyp3mf.cloudfront.net/styles/teaser_large/s3/imagelibrary/n/neutron_elements-OX_rbrAQu2UdiEoW1Ecl2I1Ejfjg9wA8.png)
If the manufacturer decides they want a safety device to shut down the heating element (or the whole machine) if the water level drops too low in the boiler, this is usually done by fitting a second longer probe, which is always in contact with water in normal operation as it is usually somewhere around 10-15mm below the main probe, so extends below the normal range of variation of water level. This is to avoid the autofill activating too often or switching on/off rapidly if the water in the boiler is sloshing about (if the machine is bumped, or in a van, on a cart etc.) Most also have a timer circuit associated with the probe, so that autofill is only activated or ended after 2 seconds of the water dropping below the probe or reaching the probe when refilling. Most machines use the probe as a simple binary input (open circuit or closed circuit depending on whether the tip of the probe is touching the water). Easy to fix once you know what causes it, but not the most obvious thing to check at first. There is often another timer associated with the autofill circuit to protect the pump - if the autofill is activated and the probe does not sense water within a set time (often 90 secs for many Gicar units) it turns off the autofill to avoid overheating the pump, on the assumption that there is no water flow into the boiler. The control circuit probably incorporates some hysteresis to avoid frequent pump switching when the tip of the probe makes or breaks contact with the surface of the water in the boiler.Most machines use the probe as a simple binary input (open circuit or closed circuit depending on whether the tip of the probe is touching the water).