Based on picture added by Homeburrero in another post (ECM Giotto's OPV rubber connector) I would replace the existing expansion valve (#2 in my pic) with the new OPV valve.

Yes. My original and the replacement are both pictured in this post: ECM Giotto Classic - problems with leaking & boiler level

Hi Homeburrero.
I just received my Schneider Electric Relay 300XBXC1-120A 30 A just like the one pictured below.


There are two connections I would like confirmation before I proceed to add this relay to my ECM Giotto.
1. To any NEUTRAL after ON/OFF switch.
2. To any LIVE after ON/OFF switch.

Do you have any pictures of how/where you did these connections?

I have a new Pstat and water pump installed now just waiting to wire in my Relay and to install new OPV valve.

Sorry but I don't have a photo that would help. Also my old ECM's wiring and controller differs from yours and may be confusing.

Here's an example of how you might hook one up via wires that go to the controller that I hope may be helpful. It uses pin numbering and diagram from that XBX DPDT relay:



Note that this one powers both the control and the load via the Resistenza / Riscalmento pin out of the controller. One advantage here is that even if the contactor in the relay fries shut, if the controller is not allowing power to the element it will not be powered.

The wiring through the pStat will not carry much current, but the wiring from the controller through the relay contacts will, so you want to use heavy wiring for that.

How you go about teeing into existing wires depends on what kind of connectors you have. A 0.250" piggyback spade terminal is a common way to get a nice tee, although you can use a butt splice connector that takes two wires at one end. If you don't have a good crimping tool you may be just as well to connect 3 wires into an appropriately sized wing nut connector.

Was looking forward to having my Giotto running again, but no success.
I replaced the Pstat with Mater. I replaced the EX5 water pump. I replaced the OPV expansion valve. I fixed a burnt wire. ( I did not feel competent to add a relay.)

I put the side panels on and top panel. Inserted the tank with water. I tuned the switch on and heard a click and 1-2 secs later another click, but nothing happens. Pump does not turn on.

It's getting hot in my garage so left the machine as is while I figure out the next steps. Most likely I will take the panels off and re-check the wiring on the water pump and Pstat. How can I test to make sure the water sensor is not the problem?

Replaced a connector on the water sensor wire. Cleaned the contacts with very fine sandpaper. Bypassed the water sensor and turned it back on. Boiler heating and pump is working. PStat is stable at 1-1.1 with 207degF on Eric's temperature sensor. This is down almost 10 degrees from original condition. This was my goal. Set the pump to 10 bar at the grouphead. Was originally at 12 bar.
I will finish re-assembly and run a couple of shots. Pics to follow.

Good news!

P.S. That reservoir sensor on the old ECM and Rocket Classic machines is a frequent cause -- the controller thinks the reservoir is empty and prevents the heater, pump, and fill solenoid from getting power. The light stays green (on newer machines it would blink).

There's a spot where a reservoir sensor pin rests in a steel or brass cradle. On mine, poor conductivity here was a frequent cause of this symptom -- by pressing on this connection at the top of the reservoir the controller relay would close and the machine would start heating. Cleaning that connection's surfaces every time you clean the reservoir is a good idea.

Thanks to all of you that helped me get my ECM Giotto working properly. Special thanks to Homeburrero. Wishing you happy trails in New Mexico. I love Southwest Food. My wife and I spent a wonderful vacation in Santa Fe some years back.

Only 1 short pic of my first Espresso with my machine. It tasted very good. Lifeboost Espresso Blend.