OK guys, I need some help getting our Giotto back in action again. Yesterday the safety valve popped and released boiler pressure; pressure gauge read 2 bar; and the heating element was still on. I turned it off immediately, and have not turned it on since. As my knowledge of the inner workings of the machine are somewhat limited, I thought I'd check in here for some advice.

I'm surmising that the pressure switch is faulty. Am I on the right track here? Is there a way to test the pressure switch? Could there be any other cause of this problem? Electrical fault? Loose or corroded wire?

I should also mention that the machine was idle at the time of the overpressure. There was no shot being pulled, steaming, or hot water being drawn. It had been idle for several hours, with no activity of any kind.

At this point, I have not opened up the machine to have a look, pending some feedback and helpful pointers from here. Thanks in advance....

Svend

The diaphragm on pressurestats will stiffen and can scale over time. They will all eventually fail which is what it sounds like you have. You can take the pressurestat off, put a little vinegar in it and let it soak for a while, then rinse it out to see if that fixes it. Sometimes simply tapping on top of it will un-stick it but if it happens again, you would be best to clean it or replace it. The are relatively inexpensive.

Search on "sticky pressurestat" for similar reports and suggestions.

Thanks! This place is the best! I'll try that tomorrow and post back with what happens.

Quick question: when I take the Pstat off, what should I use to reseal the joint? Teflon tape?

SNielsen wrote:Teflon tape?

Yes.

So, here's the latest.....(problem still not resolved)....

I took the Pstat off from the top of the coil tube, and found that the tube was full of water right to the top. Is this a normal condition? Is the water level in the tube too high? BTW, no water leaked out when the Pstat came off, and the unit was dry, so no water made it up into the stat itself.

I soaked the stat in vinegar, as suggested, rinsed and re-installed. Reassembled the machine (leaving the side panel off), and turned on. Instead of the boiler filling and heating, there was a continuous clicking from the Gicar box, like a relay clicking on and off, freq about twice every second. This is the same condition that I posted a query about a couple of months ago (see here: http://www.home-barista.com/espresso-ma ... 10530.html) The clicking problem never got resolved, BTW, as I've had no time to look at it -- way too much travel; out of town almost constantly since April. So we just left the machine on 24/7 and thus avoided the startup clicking problem.

In any case, with this relay problem, the machine won't fill the boiler, nor will it heat. So bottom line is, with the machine not heating, I still don't know if the Pstat problem is solved. And now I have to fix the dang relay first.....

OK, regarding the relay now......I did as suggested in the previous thread, and pulled the water level probe out of the boiler today while the stat was getting it's vinegar soak spa treatment. The probe was pretty clean, but I polished it all up nice and shiny with some emery cloth. When the clicking started, I tried grounding the probe lead, but this had no effect....the clicking just continued as before. Unless you guys have another suggestion, it seems to me that the relay is funky and needs to be replaced. I looked inside the Gicar box, and everything is soldered to the circuit boards. Does this mean I need a whole new Gicar? Or can I get a new relay only, and just solder the new one onto the board?

Cheers, and thanks...!

Svend

relay? i dont think the giotto has one.
similar probs on mine pointed to a failing gicar controller.

Hi Eric! Took the day off for Father's Day, so no progress to report today. Will take some pics tomorrow and post back here. If you're a Dad, hope you had a good Father's Day too!

BTW, my Giotto does not have a mini-reservoir under the main water tank, and thus no sensor in there. I think the newer models have this, and in these the water is drawn from the bottom of the tank. I have an older machine which has hoses which drop into the tank from the top (I do have pics of that....see below). Low water is sensed by a two pairs of metal prongs which hang into the tank from the top edge. The outer edges of the frames from which the prongs hang, are short metal bars and are used to suspend the tank around the machine frame. One of these rests on a contact to which is attached a wire lead which is directly connected to the Gicar. The other side rests on the machine frame (ground). When the water level drops below the bottom of the prongs, the circuit is broken.

This is a pretty simple system, with no sensor to fail. Tomorrow I will check the contacts and ground to make sure it's all sound, as well as clean all the bars and prongs of scale and corrosion. Not sure if this could cause the relay to behave like that, but I will test and clean nevertheless.

(Note that in this pic the top edge of the tank shows the sensor bars sitting loose on the tank edge where the holes in the side of tank have broken. This is an older pic, and I have since redrilled the tank and remounted the bars to give proper contact)

So, I had some time last night to put my head into the machine again, and found that grounding the tank sensor prongs and contacts had no effect on the clicking relay. I grounded the bars, prongs, wire, etc., six different ways, and no change. Before that, I had checked the continuity of the prong to the connector at the relay, and it was sound. Likewise on the other side of the circuit - the ground contact of the opposite prong was good.

So, with the tank sensors testing OK, and the boiler sensor likewise, I'm left with the conclusion that I need a new Gicar box. I assume that separate relays are not available. Unless anyone has any other suggestions, I'm pretty much resigned to putting a new Gicar in. FWIW, here are the pics that Eric was looking for:

Hi Eric,

Yeah, the top of the Gicar box looks a bit toasted. Not sure why. We bought it as a used machine, about 2 years ago, and don't know the full history. Looks like an '03 model, judging by the serial number (20031105299), so it was in use for about 4 years before we got it.

Thanks for the link to the relay supplier. I'm OK at soldering big stuff (wires, plumbing...), but when it comes to circuit boards, that's a bit too fine for me. Don't have the dexterity and know-how to do a good job (the actual soldering part is not bad, it's getting rid of the old solder and opening up the holes in the circuit board for the new pins that's tricky for me....that, and I've overheated a board or two.... ). At this point, I don't have the time to fuss with it, nor the confidence that I will actually be able to get it working again. Gotta lump it and pay the bucks, it seems.....sigh....

I just called Faema in Toronto, where the Giotto originally came from. They will install a new Gicar for $300, and for an extra $130 they will fully test the machine and inspect to see if everything else is OK. They have several different models of Gicar in stock, so should have the right one. The service guy was impressed with my knowledge (grounding of sensors, relays clicking....), but I didn't tell him I learned it all here!

Thanks a ton for all your help. Much appreciated!

I am currently experiencing the same problem and Eric has been a HUGE help in trying to diagnose the problem. My machine reaches an overpressure situation when pulling a shot but not necessarily right away (usually about 6-10 before a problem).

I have the same Gicar as you and through some simple tests and inspections it appears that my RL1 is faulty. RL1 on my board closes when the machine is powered up but does not open and close with the pressure stat. I swapped the p-stat for a light switch and checked for relay operation (still no) and also measured the voltage on the heating element when the "p-stat" was on and off. When off, I was still reading between 5V and 12V on the leads when it should have been 0V (right?).

After much searching, I was able match RL1 (JQX-14FW-018-HS) with this:

http://www.newark.com/jsp/search/productdetail.jsp?sku=04M9461&_requestid=272245

I will be testing tonight, so I will let you know how things turn out. I hope my soldering skills are up to snuff! Also, I contacted Stephano and he was able to source a Giemme replacement controller used on the ECMs that is less expensive. PM or email me and I may be able to help you some more.

Cheers,

Matt

Hi Matt,

Thanks for the input on this. I'd gladly source out the relay and put it in myself, but, as I said, I'm not sure I'm up to the soldering task. If I had more time too, I might attempt it, but I travel a lot on business, and just don't have the time needed to sort this out right now. Personally, I'd prefer to repair it myself, as I enjoy the challenge and like doing the work. If I wasn't so busy, I'd probably give it a shot, and save some money too..... But dropping the Giotto off at Faema and having them take care of it is looking pretty good right now. Expensive, though....ouch.... Oh well, at least it's an excuse to visit downtown Toronto (great city!). And Faema has a really good restaurant/cafe on the main floor, in which a good lunch followed by a cappuccino will soothe the pain of the repair bill.

Good luck with your machine, and let me know the outcome.

And you're right, Eric is a great help. Very knowledgeable....Thanks Eric!

Svend

reno - this is the same issue i had. i took resistance and voltage readings across all points, and it appeared to be a growing issue. as heat affects one relay, it spreads to others shortly thereafter.

again, i swapped the gicar controller. there is always the simple solution, cycle the machine often and live with cool shots. i did that too, until the controller completely failed.

Leo -- Thanks for the insight. It does seem that the board overheats and causes problems throughout, so changing out RL1 didn't make a difference. On this last go, the machine overheated on the first shot. By the way, I got through about an ounce of my shot, Ristretto Roasters Ethiopian Harrar, pulled pretty tight and it was a gobs of dark chocolate with hints of sweet berry in the finish!

I think I've exhausted my electrical know-how and patience. Time for a new controller for me, too!

Cheers,

Matt

I have had a problem with over pressure several times with my Europiccola. I used descaler instead of vinegar, not letting it get to full pressure before running it threw. I have done this up to three times in a row before it returns to normal operation. It happens like clockwork if I put off cleaning the machine.

I doubt there is any scale in the machine anymore. I had it completely apart and descaled for a couple of days with citric acid solution. The boiler was nice and pretty when finished.

I discovered that I had my wiring for line and neutral reversed at the switch (I feel like such an a**) and rewired. Everything appeared to check out, so I fired up the machine and monitored the operation. I got through 3 shots with no problems and then tried two blind filter backflushes. The second caused the over-pressure situation, so I stopped the brew cycle before blowing the safety valve. I then pulled another real shot to be certain of the problem and experienced the same. In both over-pressure cases, I am able to immediately flush water through the group with no portafilter without problems.

So now I ask this: Do I have a possible leak in my HX system or possibly a faulty one-way valve and fill solenoid, which causes the boiler to fill and over-pressurize? Could the problem still be some sort of electrical issue on the board (over-heating), as Leo stated earlier?