Hi,

I have an ECM Giotto with a reservoir.

As I am sitting in front of my computer, I suddenly hear a loud hissing sound from the kitchen. As I rush there, I hear the security valve releasing pressure, and the boiler pressure gauge at 3-4 bars.
After I turn off the machine, let it cool, then turn back on. The heating element wouldnt kick in.
I opened up the machine, and pressed the red reset button on the thermostat, after which, the heating element is working again.
However, the problem is the machine heats up to working pressure (1.3 bar), then the heating element switches off. The pressure then slowly drifts down to 1.1 bar where the heating element goes on again for 2 seconds, the pressure is back at 1.3 bar, turns off again - and so on and so forth.
So basically the heater is switched on and off about 3 times per minute. It didnt use to do it so often before the malfunction.

I thought maybe the water level probe is defective or scaled, so I took it out and gave it a thorough cleaning with descaling agent, and plugged it back in. Didnt help. I disconnected the water level probe lead to force a slight overfill, and check again, even when I topped off the boiler the pressure isnt as stable as before.
As a last measure, I emptied the boiler, descaled the machine overnight (All passageways, including steam wand, grouphead and hot water spout), and flushed it out and replaced with clean water.
The behavior is still the same.
The vacuum breaker works fine, the pressure switch also seems to work fine as adjusting it changes the tripping point accordingly. Water level probe also seems to work fine.

I dont hear any hissing sound after the vacuum breaker is locked, and dont see any visible leak.
I'm totally lost - anyone has any idea what could be the problem?
I can brew coffee and steam just fine, there is no noticeable decrease in pressure when steaming. The steaming is now even better after the descaling. Brewing is also fine.

At the rate this thing is going I'm afraid the relay will die in a few short months.

Any ideas would be greatly appreciated.

You're losing pressure some where...

Until you can track that leak down, and fix it; there is not much else you can do.

Anti/vac valve ? Safety Valve ? Fitting ?

How can you track it down? If it's leaking, the leak is so small I can't see or hear it.

Use a small inspection mirror ( i use a telescoping automotive style) and hold it above all pipe connections /boiler covers and valves. Steam will collect and fog mirror on leaks.