Hello HB,

i recently moved up ( ..or down ) from a fully automatic low-mid range Saeco to a factory-new La Pavoni Professional Lusso. Please bear with me if i'm posting a trivial question here, i did search through this forum, google, and the manual, but found nothing relevant.

With that out of the way, here's my problem: 2-4 minutes into a cold start and a fresh re-fill, i see hot air exiting the pressure relief valve. I am told that is nothing to be concerned about. However, another 2 minutes after, it is steam at a fairly high pressure that is exiting the machine via the safety valve, and continues to do so until i shut it down to protect the heating element from running on a completely empty container.. At peak, my pressure gauge reads 0.25bar.

- could my pressure gauge be broken? ( out of the box.. )
- could the relief valve be broken or badly assembled ( ? ) ( out of the box.. )
- what could i do to diagnose this problem better, short of returning it to the vendor?

The machine never produced a pressure in the "green zone" ( again, according to the gauge ) so i never tried pulling a shot. All it did so far is humidify my apartment. Which is nice and all but with my previous full-auto out of the picture, i'm getting withdrawal symptoms.


any suggestions are highly appreciated.

thanks,
Andras

The problem is almost certainly the pressure relief valve.

Pressure relief valves are very very simple devices. They consist of a valve seat, a ball or mushroom shaped part that fits into the valve seat, and a spring that pushes the ball or mushroom against the valve seat. Anything that gets into the space between the valve seat and the ball or mushroom will cause serious leakage. This will also result from corrosion of the seat or deterioration of the ball or mushroom.

I think the 2014 valve is still like the original 1961 one. One can clean this or check for deterioration by simply removing the 16mm holder with an appropriate 16mm tool. After cleaning or replacement of a defective part, one can simply reassemble. (Be careful not to allow the spring to put the ball or mushroom into orbit when you take it apart.)

On all pressurestat equipped La Pavoni steam should only escape from the relief valve when the pressurestat fails. Under normal operation STEAM SHOULD NOT EVER BE EMITTED FROM IT!

Thanks! I will have a look tonight.

TBH I am yet to run a cleaning solution through it .. i just can't picture limescale affecting a brand new machine?

Your problem seems like a pretty straightforward one -- as Robert says, a stuck OPV. There won't be scale in a new machine. Since you got it new, what has the seller done to make it right for you?

BTW congratulations on your upgrade! Wait until you experience the quality of espresso it's capable of producing, especially if you equip it with a group thermometer, giving you the readouts needed to tune temperature to specific coffees.

drgary wrote:Since you got it new, what has the seller done to make it right for you?

right now they are blaming the gauge. Which i think misses the point completely - which is, as rpavlis mentions

rpavlis wrote:On all pressurestat equipped La Pavoni steam should only escape from the relief valve when the pressurestat fails. Under normal operation STEAM SHOULD NOT EVER BE EMITTED FROM IT!

here's their reply..

from your description, I understand that the machine should be under pressure, and therefore tends to empty the container. This means clustering That the machine is ready to work, then the problem is in the gauge that shows the exact pressure.
You should try to make coffee when the machine starts to eject steam, and if it is hot then the machine is OK. La Pavoni coffee is always hot. If it is warm then there may be another problem.
Try to prepare a cup of coffee and then you tell me.
The replacement of the gauge is simple, you could solve the problem by simply sending a new gauge.

I suspect the seller does not understand the machines that he is selling! Steam NEVER should be emitted from the pressure relief valve except when there is a failure of the pressurestat. The spring on pressurestat machines is deliberately made strong enough so that its release pressure is greater than the normal pressurestat turn off pressure. The pressurestat will not ever turn off when the pressure valve releases too early!

A little clarification
Since the Millennium editions (or a little before and a little after depends what they had around in the factory floor during assembly........)
the teflon mushroom valve on the pressurestat models have been replaced by the
brass plunger one,
the brass plunger is not only a safety valve but acts like an anti-vacuum valve as well,
so it IS suppose to let cold/negative air out of the boiler until there is enough pressure to seal,
after it seal,
since there is always a little water remaining in the "drain cup,"
it will hiss for a while until the water is dried out,
if of course it will leak after that
try to tap on the safety valve cover with a soft tool to see if it will seat, it not follow the descaling cleaning replacing etc etc,
just for your info this is how the "newer" style valve looks like

stefano65 wrote:if of course it will leak after that
try to tap on the safety valve cover with a soft tool to see if it will seat, it not follow the descaling cleaning replacing etc etc,

+1

I've had a couple go sticky, both times after being emptied and shipped, and in both cases a rap with a wooden mallet freed them up and they continued working fine with regular use.

Thanks everyone,

stefano65 wrote:try to tap on the safety valve cover with a soft tool to see if it will seat

..boom, fixed! Much appreciated. Its a bit unsettling though.. should i still look to have the valve cleaned/reinstalled/replaced?

update: it seems i have to do this every single time i turn on the machine after letting it cool for a while..

andlaz wrote:update: it seems i have to do this (tap) every single time i turn on the machine after letting it cool for a while..

That's not normal or right. You should contact your vendor and get this fixed. There is no need for users to tap their OPV everytime the machine starts up.