Bezzera Strega - not holding steam pressure

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F.M.

#1: Post by F.M. »

Some expertise would be much appreciated! I've exhausted my troubleshooting skills.

My Bezzera Strega starts up fine and boiler gets to 1.25bars. But after any use that causes the pressure to drop, it just continues to lose pressure and the heating element does not come back on.

I have replaced the mater pressurestat, heating element and anti-vacuum valve. No changes. I have also tried adjusting the pressurestat.

I had also recently de-calcified and replaced the pump, and I think that may be related. I found a brown wire that seemed to have gotten partially pulled out of the wiring harness plastic connector, and the connector looked partially burned. However I repaired that connection, and the problem persists, so maybe it's unrelated.

Any advice would be much appreciated!

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baldheadracing
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#2: Post by baldheadracing »

F.M. wrote:... My Bezzera Strega starts up fine and boiler gets to 1.25bars. But after any use that causes the pressure to drop, it just continues to lose pressure and the heating element does not come back on....
Hmmm. Okay, let's say the machine is turned on, warmed up, vacuum breaker seals, boiler gets to 1.25 bar, and then starts to drop. Let it drop to 0.9bar. At that point, what happens if you then flick the power switch off, wait five seconds, and then turn the power back on again?
What I'm interested in is my worst espresso being fantastic - James Hoffmann

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F.M. (original poster)

#3: Post by F.M. (original poster) »

It seems to hold pressure until I steam milk or do anything else. Once it begins to drop the boiler won't come back on unless it's a cold start. Cycling the power doesn't kick it on. Mysterious.

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baldheadracing
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#4: Post by baldheadracing » replying to F.M. »

So it sounds like it might be electrical. The low pressure side of the pressurestat appears to be not turning on the heating element. (I am assuming that you can hear the pressurestat clicking 'on' when the boiler pressure drops.)

That burnt brown wire seems like it might be the clue.
What I'm interested in is my worst espresso being fantastic - James Hoffmann

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F.M. (original poster)

#5: Post by F.M. (original poster) »

Follow-up: took it to a local pro who's ended up being great to work with. He tracked the problem down to a faulty relay. Rebuilt the group & piston with new seals while he was at it. I am also getting the case blackened and patinated by the metals shop I work for. Excited to get it all back together!