Hello,

I have a new behaviour of my PV Lusso that feels like a pstat failure. I keep the pressure set around 1.1bar - up until recently, the machine would hold that pressure fairly steady no matter how long the machine was on.

Recently, if the machine has been on for 45min or more, the pstat almost stops working almost all together - it keeps the pressure around the 0.1bar point.

After the machine is off for a while, the pstat again works perfectly - unless of course the machine is on too long.

Is this a pstat failure? Something else?

Thanks.

I am not sure about the ponte vecchio ps but on my Sama the pressurestat pivots around a small bolt on one end with the adjusting screw on the other.



When I first got the machine I had issues with irregular pressure settings, though mine tended to creep upwards not down. After cleaning the rust and adjusting the nut to be just snug instead of tight the pressure is very stable. Anyway, clean and lubricated is always a good place to start.

bmac.to wrote:Recently, if the machine has been on for 45min or more, the pstat almost stops working almost all together - it keeps the pressure around the 0.1bar point.

After the machine is off for a while, the pstat again works perfectly - unless of course the machine is on too long.

I had a temp sensor on my La Pavoni that was acting just like that. Once the machine heated up for a while I would have no heating element power at all until pressure dropped to near 0 BAR, and then it would climb right back up, work for a while longer and then when I have to steam milk it will go out on me again! Seemed like it always likes to mess with my milk steaming - ever try steaming milk at 0.5 bar on a La Pavoni???

It's 30 years old, so time for a replacement sensor, but in the meantime I've temporarily wired around it.

You might want to make sure you don't have a faulty temp sensor switch on the system. (I don't know the Lusso enough to comment on that.)

You've got a very different pressurestat than I do.

Working fine for 45 minutes and then failing after sustained heat makes me wonder if the microswitch on your PSTAT is failing. Electronics can go buggy that way. Orphan Espresso has a Mater PSTAT on closeout for $16. Even if you need an adaptor for your fitting size switching that out may just solve the problem. Otherwise have you checked your contacts? Have you checked for shorts caused by steam or water leaks? Someone else may have good diagnostic ideas for the latter.

I will check the contacts and for leaks - plus, I have the pstat from OE on order.

I will let you know what ends up fixing it.

Thanks!

I finally got around to replacing the pstat. The reason was that the failure become intermittant - I would have a week or so of no troubles, then it would act up once or twice, then start working correctly again. This past weekend, it failed completely.

Replaced the pstat with the one I got from OE and all is well.