Hello All,

I am a newbie to the site, but have read it for years. I have a Oscar Simonelli and have decided to try and see if I can save the cost of having a repair person overcharge me and do it myself. Please be frank if you think this is above my minimal mechanical abilities. I certainly could unscrew the unit below and replace it.

First symptom was blowing house fuses then,

It was leaking water so I took off the top and saw where the unit on top of the tank was squirting water. Is it because of built up plaque somewhere else. Is it possible to do something to reset it. Or if I just need to replace the unit on top as it screws off easily.

I guess the question is: Is the protection broken and thats why water is leaking from the 2 spots indicated, or it there another reason. Any help would be greatly appreciate.

I am in France and it costs' an arm and a leg to get any repair done.....

Keep in mind though: water and electricity together can be hazardous, couple this with pressure and it takes more than mechanical knowledge.

You might try to replace the unit on top - that is the P-Stat. Make sure the unit is off and unplugged and is not holding pressure (release pressure through the steam wand).
The brass unit is a relief valve.

I'm going to speculate here:
Your P-stat probably failed allowing the boiler to get too hot, hence too much pressure. The relief valve then probably did its job and relieved the pressure.

Im so happy someone answered. So its the P-stat which protects the boiler from overheating.

Right before the problem, the unit was out of water (happened a couple of times) and the only way to get the water in to the flow was to actually put my mouth over the reservoir and blow pressure into the system.

So the boiler might have been low, or my pressure caused something to happen.

Is it a common occurrence for a P-Stat to blow ?

What are some of the things to cause a P-Stat to go.

Fortunately I live in France and its just an overnighter to get something from Nuova Simonelli. I speak fluent Italian so I could probably order it over the phone from the factory and do the install which is straight forward.

Oh Is a P-Stat expensive

My Oscar has a Sirai P-stat. I think yours is either a CEME or a Mater.
The Sirai here in the US goes for $95 USD (see Chris Coffee website). I believe the CEME or Mater is less than this.

I just read a review about the p-stat and problems people were having and now I understand.

I will ask the factory for the new type p-stat

I unscrewed the unit and it came off easily although at first it seemed the skin of the boiler was supple or thin. But it came off and would be easy to replace.

Questions:

1. When I put the new one on, do i have to do anything with filling the boiler up or does the air evacuate just like it would if it ran out of water ?

2. Might this not be a good time to de-calcify the inside of the boiler, but I haven't the faintest idea how to access the inside of the boiler.

3. I've had the machine for probably a year and some, is there anything else to do. I only change the gaskets and filters on the group so far. Where I live the water is very very high in calcium.

4. Lastly, with a new pressurestat does it matter how you install or screw it in to place. It just measures temperature right ?

Sorry for all the questions, just trying to learn thanks

So its the P-stat which protects the boiler from overheating.

No, the P-stat controls the steam pressure which regulates the temperature.
Is it water or steam which came out from the places indicated? If water then I think the water autofill system is faulty, I had a similar problem with an old commercial machine, the auto fill box went faulty and filled the boiler with water.

Right before the problem, the unit was out of water (happened a couple of times) and the only way to get the water in to the flow was to actually put my mouth over the reservoir and blow pressure into the system.

Sounds like an autofill issue.

Bruce -

With the questions you are asking and the comments you are making, I suggest you visit the Nuovo Simonelli website (Italy) and locate one or more dealers/repair facilities in your location.

http://www.nuovasimonelli.it/

It seems to me that your Oscar may have several problems (either existing or about to exist) that simply replacing a pressurestat or removing and cleaning a water level probe won't necessarily cure.

One immediate concern is the quality of the water you feed the machine. Given your comment about the calcium content of your water supply, I suggest you look hard (no pun) at a filtration/softening system so that, once fixed, these problems do not repeat.

Well I spoke to a technician at Nuova Simmonelli and he said it was not complicated to replace the pressure-stat. The fact that my wife let the machine run out of water continuously was no coincidence with what happened.

I do notice the pump making louder noise to do its work, which makes me think I need to do a thorough cleaning in case calcaire has built up.

What product should I use to flush through the system ? and Is it possible to get on the inside of the boiler to clean it or the pipes coming out of it. I would really like to learn and do this stuff myself if I could.

thanks for all the help

I second Eric's advice to get your espresso machine professionally serviced.

I lived in France for four years (Vence for two years, Paris for two years) and remember the water was extremely hard. I doubt that the preventative maintenance descaling with citric acid described in this forum will be strong enough to remove the buildup. That said, assuming you're comfortable and qualified, removing the heating element and peering into the boiler will remove all doubt about the level of calcium buildup.