The stock pstat for the PVL is the ubiquitous Mater XP110. A simple modification that I have been holding off on is drilling couple holes into the casing to easily access the pstat and thermo reset switch. Hole location for the pstat would be dependent on the brand of pstat. The original Mater pstat might be starting to fail. Previous dying Mater pstats in other machines have exhibited similar behavior before failure. The PVL is on a timer for AM espresso. ~2 hours on prior to use. Mater pstat failure in a non direct plumb machine on 24/7 can be messy and dangerous. Even on for couple hours a pstat failure would not be a good thing to happen.

So thinking about a commercial grade replacement. Probably the Sirai. Is the Sirai pstat a viable option for the PVL?

Sirai's are about as expensive as an auberins PID controller, screwable thermocouple and SSR. That set gives the added benefit of no deadband, can be adjusted without opening the case, is completely silent and you won't have issues with hardening membranes.

The Sirai's size might be an issue, though -- it's a tight fit under the casing. I would consider a Jaeger pstat, but even then, I would check for sufficient clearance. Let us know what works (someday I might consider a pstat substitution, too).

Ciao,
Wayne

Bluecold wrote:Sirai's are about as expensive as an auberins PID controller, screwable thermocouple and SSR. That set gives the added benefit of no deadband, can be adjusted without opening the case, is completely silent and you won't have issues with hardening membranes.

Would this setup require the thermocouple to always be submerged? That is to say, will the water level always have to be above the TC (and therefore above the point where the pstat is located in a stock configuration)?

On second thought, the steam and water should be at the same temperature (PV=nRT), right?

As far as the deadband goes: do we even care about it on this machine given the thermal mass of the group and the fairly quick steam recovery (the element can hold or even raise the pressure while steaming)?

Note: not saying this is a bad idea, just wondering if it would be worth the money. I do realize that you suggested it as a space saving, conveniently adjustable, and robust (is that the right word here?) alternative to the bulky Sirai, making no comparison to the cheaper Mater.

And about the pstat failure, I think we're well protected on the Lusso. Either the pstat fails on, overpressure valve releases steam, and low-level sensor cuts off the element, or the pstat fails off, and the machine cools down. However, if your overpressure valve is jammed, then the stuck on may leave you with a bit of an explosion.

narc wrote:The PVL is on a timer for AM espresso. ~2 hours on prior to use.

Wow - do you feel it really needs that amount of time for warm up? Certainly with mine 15 mins + false pressure release + warming flushes and by the time I grind, distribute and tamp then it is ready to go.

Entirely your call obviously and it might be a good mod to make purely for the fun of it. Reliability issues aside, I dont think the deadband is a real problem given the group's thermal stability (as pointed out by aindfan) and the tiny deadband that exists anyway. And I wouldnt say it is loud either - far from it.

A further safety feature is that there is also a thermostat attached to the heating element that it will kill power if this is tripped, should there be a pressurestat/safety valve/low water sensor failure.

I have been toying adding an insulating cover around the boiler, which would help retain boiler temperature and therefore less boiler cycling, saving wear and tear on the pstat. That might be an alternative if you do indeed have your Lusso on for extended periods.

But I do appreciate doing things for the hellofit as well!

Here is a photo group of the modifications needed and used on new machines when Orphan Espresso was selling them. All worthy ideas. Click on a photo to enlarge. They still have some parts for them also.
Orphans' PV Lusso mods
Good folks there!
-Richard

Very worthy mods. What a shame they're not selling them any more!

Richard, thanks for the link to the mods. The 90 degree pstat fitting with access through the plastic inner lid is nice.
ziobeege, 30 minutes warm up followed with a purge of the groupheads has been adequate time. Depending on work schedule, day off my normal wake up time is usually within a 2 hour window. Only reason to set the timer for 2 hours. Insulating the boiler has been the only "modification" done to the PVL. It has been couple years. It does cut down on the number of heating cycles per hour and makes the machine run very quiet even during the initial heating. Don't remember the difference between uninsulated and insulated. For non24/7 use it's probably not a huge energy savings. Might prolong the life of the electronics.

I could be wrong, but I don't think pressurestats hold up well to frequent adjustments. When I do set mine initially (no plastic cover inside), I do so with a right angle ratcheting screwdriver from Ace Hardware. I like the Mater because it is available in a model that runs from .5 to 1.5.

At any rate, an access port from the side would be handy, perhaps with a swing-away circular medallion held with a screw at its top. I have replaced a Mater with a Mater, and when it snugged up the adjustment screw ended up in a different position, so an access hole might need to be a bit larger than the screwdriver.

I find my machine from a cold start is ready to go in 12 minutes, after one flush of the group, so I have never had it on a timer.

Good luck with the modifications and with finding a new pressurestat that fits your needs.

I drilled a hole in the bottom plate of my Export, so now I don't need to remove four screws if I want to adjust the Mater. Mine is four years old, and bottom-mounted, so it collects any scale residue, etc. I HAVE NEVER DESCALED IN FOUR YEARS, and its still working fine, although it may have changed slowly without my noticing. I have been using very soft water.

I've taken to vigorously shaking the Export before turning it upside down over the sink and emptying every morning (not when the element is HOT, and never leaving it empty!).

The Export warms up so fast (<1 liter) that I don't need any timer. Really, even with the Lusso, if one turned it on after the alarm rang, it seems like it would be ready before breakfast.

I do recommend testing the pressure relief valve (never done so, but its on the to-do list!). It is there for a very good reason!

PC