La Pavoni Professional losing pressure on startup

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DavinG
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#1: Post by DavinG »

My La Pavoni Professional is not even one year old yet and it recently began losing pressure on startup. Once the machine has reached operating temperature (0.7 on the gauge) I open up the steam valve for a few seconds to bleed the air. Normally, when I open the steam valve the pressure doesn't drop very much but recently as soon as I open the steam valve for the first time, the pressure drops half way and takes a while to get back to 0.7 on the gauge.

Once the pressure gets back to 0.7 and I open the steam knob, the pressure doesn't really drop as the boiler kicks back in. Any ideas on why this may be occurring??

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homeburrero
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#2: Post by homeburrero »

Your symptom could be caused by a stuck or clogged anti-vacuum valve. In the past it was venting air from the boiler, but is no longer venting air and you are seeing the classic 'false pressure' effect on initial warmup. Disassemble, inspect, and clean your safety valve assembly, which includes the little anti-vac valve.
Pat
nínádiishʼnahgo gohwééh náshdlį́į́h

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DavinG (original poster)
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#3: Post by DavinG (original poster) »

homeburrero wrote:Your symptom could be caused by a stuck or clogged anti-vacuum valve. In the past it was venting air from the boiler, but is no longer venting air and you are seeing the classic 'false pressure' effect on initial warmup. Dissemble, inspect, and clean your safety valve assembly, which includes the little anti-vac valve.
Thanks, I'll give that a try.

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DavinG (original poster)
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#4: Post by DavinG (original poster) »

homeburrero wrote:Your symptom could be caused by a stuck or clogged anti-vacuum valve. In the past it was venting air from the boiler, but is no longer venting air and you are seeing the classic 'false pressure' effect on initial warmup. Dissemble, inspect, and clean your safety valve assembly, which includes the little anti-vac valve.
I've taken the safety valve assembly apart, cleaned it up, and lubed the o-rings with olive oil. The problem seems to have been fixed on the next machine startup but then the valve seems to stick again, creating false pressure. Any ideas why the valve is sticking? What should I be cleaning the valve with? Is olive oil a good lubricant??

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homeburrero
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#5: Post by homeburrero »

I doubt that the olive oil is causing sticking, but perhaps it would be a good time to order a silicon o-ring lube, like the Dow corning 111, or the Haynes silicon lube that Stefano at espressocare sells. Both are food safe, and recommended for general use on the seals and o-rings in your machine. Use it very sparingly.

I have two millennium machines, but one is a Romantica and the other a Gaggia Factory, and these both have a different anti-vac valve than you have in your Pro. My machines' anti-vacs do their job nicely, but I have heard others on this forum say that their standard anti-vacs seem to seal shut before the air is fully purged from the boiler. Unless you are running the machine on a timer it should be no problem to open the steam wand and purge air as part of your warmup routine. You can do a purge of air from the top of the group at the same time by lifting the lever and letting a little water out.
Pat
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DavinG (original poster)
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#6: Post by DavinG (original poster) »

Just about a year later and my pressure relief valve still sticks. I've taken it apart several times to lube it but that doesn't seem to help. I've simply gotten used to opening the steam valve during warmup to purge the air.

jwCrema
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#7: Post by jwCrema replying to DavinG »

I had this exact issue with my LP Pro. I bought a new valve and never had the problem again. As I recall the part was inexpensive. I never attempted the use of a lubricant because it seemed to be a seating issue.

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DavinG (original poster)
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#8: Post by DavinG (original poster) replying to jwCrema »


Thanks, I might have to look into replacement then.

jwCrema
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#9: Post by jwCrema »

DavinG wrote:Thanks, I might have to look into replacement then.
This is what I bought:

https://www.espressoparts.com/la-pavoni ... ll-bearing

The price seems higher than I recall I paid - $ 12.00