I am about to remove, inspect and clean the pressurestat from a 2011 Olympia Maximatic, recently acquired. The boiler, famously set high typically at 1.3 bar, has, on two occasions gone up to 1.5 and 2.0 bar, respectively, and stayed there until I engaged the pump. Each time it reset to 1.3, but I see this as two shots fired over the bow. I am good at taking things apart; less stellar on putting things back together. It would help to know if any treatment of the pstat threads are indicated prior to reassembly, or none. Other pitfalls in delving into this compact-arranged marvel of engineering would be nice to know.
Replies from someone with late-model Maximatic maintenance experience would be most helpful but those who have been successfully inside a Maxi of any vintage or those with pstat rebuliding experience would also be appreciated.
Have read drgays great restoration post and hope not to have to go anywhere near there. Have not started disassembly nor peeked into the boiler as yet but I have citric acid.
Buckley

Re post title: limited.

Nice machine, no doubt. Build quality of the vintage machine is such that I am surprised that the P-stat is not functioning. Based on 1983 Oly Maxi experience I would think that if you loosen a fitting and see any sign of treatment such as plumber's tape then use it, otherwise just add a dab of Dow as you reassemble.

Will watch for others' responses as I have only rebuilt one pressure stat: a large Sirai. It was fairly straightforward. Worked well once I replaced the teflon thingamajig. There was anyway no difficulty with the fittings upon reassembly.

I replaced mine under warranty. The part was supplied by Cerini even though the machine had been bought from OE. In my case, the pressurestat was sticking and the pressure would just build. The first time that this happened, the safety valve blew.

Before the replacement, I was able to have the pressurestat function for a bit with a descaling. However, the machine had to be watched carefully.

Joel

Chert wrote:a dab of Dow as you reassemble.

Good idea.

ilVecchio wrote:I replaced mine under warranty...Before the replacement, I was able to have the pressurestat function for a bit with a descaling. However, the machine had to be watched carefully.
Joel

Hmmm. Was hoping that is not the case here, dont want to spend more... But, don't want to live under a cloud of, "when will it happen again?"
B

What amount do you use, when your descaling the machine?

Most boiler pressure release valves open at around 2-2.5 bar so if your pressure climbs too high you could end up with a mess. The big pressurestats like the Sirai's can be rebuilt relatively easily and kits are available for them. The little pressurestats are a replace item and relatively inexpensive.

Recently rebuilt an '84 Pasquini Livietta, a rebadged Olympia. Everything needed a deep descale. The pstat was the accordion type so what I did was stick it in a small vice upside down and filled the bellows with an eyedropper, emptying and refilling daily for about a week 'till finally got it so there was just clean solution coming out. When using the eyedropper you need to 'pump' the bellows a few times to work the air out. Also make sure the switch and lever assembly work smoothly. Not sure how delicate the bellows is, so go easy on the pumping.

Once I got the machine up and running again it held a nice steady 1 bar with about a 1/2 bar fluctuation(if memory serves).