Richiekess and Baristaboy, thanks for your suggestions.

I will recheck all of the physical connections. I have not yet checked the connections to the relay that is on the back of the faceplate but will do so. I have a fluke multimeter and will check the continuity of the solenoid and the 2 boilers. Should I also check resistance and if so is there a spec for that? I didn't mention earlier that the PID box does warm up when the unit is plugged in, which I would assume is normal as the transformer sheds heat.

Thanks again

EdSilk wrote:Richiekess and Baristaboy, thanks for your suggestions.

I will recheck all of the physical connections. I have not yet checked the connections to the relay that is on the back of the faceplate but will do so. I have a fluke multimeter and will check the continuity of the solenoid and the 2 boilers. Should I also check resistance and if so is there a spec for that? I didn't mention earlier that the PID box does warm up when the unit is plugged in, which I would assume is normal as the transformer sheds heat.

Resistance of the solenoid and that of the brew boiler is indicated in my attached pics. Steam boiler element will be slightly different from brew boiler. What you don't want to see is either opened or shorted.

I was going to ask about the PID, if the display is lit then the transformer is OK. Which version of the Izzo Alex Duetto do you have; does it have mechanical or solid state relays (SSR)?

How capable/experienced are you regarding trouble shooting; down or up to what level would you rate your knowledge and experience? Can you follow a schematic diagram?

Are you aware of best electrical safety practices to not injure yourself?

EdSilk wrote:I have a fluke multimeter and will check the continuity of the solenoid and the 2 boilers. Should I also check resistance and if so is there a spec for that?

It would be quite the fluke (sorry!) that both elements burn out simultaneously but you may as well rule it out. It's always possible one broken element is causing the computer to refuse to power them both.

You could check a service manual for an exact spec if it exists, but given the wattage of the boilers, you should be looking for something in the 10-20 Ω range. Anything below 5 Ω is effectively shorted and would draw so much power that it would trip a breaker or fry a relay upstream.

Oddly enough, after working on the machine for several days and after it had been on all day and was dead to the world at room temp, I left the machine on and went to pick up my multimeter at my shop, and when I returned home, the machine was hot and up to pressure (both boilers). It has to be either ghosts, or the PID. ;->

Earlier I had opened up the expansion valve to look for blockage, and I'm not certain how to get it back to the correct setting. it is an Alex Duetto 3 and I've posted a picture below of the valve type. The procedure I have written down previously (which may be wrong) is:

Loosen the set screw on the valve, turn the screw on the top of the valve counterclockwise to back it out quite a bit, then increase brew pressure using screw on motor, to 12 bar, then turn the screw on top of valve clockwise until the dripping from the tube stops. Then tighten set screw on valve, and finally, set the brew pressure back to 9. I tried this and there is no water dripping out of the tube at 12 bar, the tube only trips when then steam boiler comes up to pressure. so I'm not sure how to set the expansion valve correctly.

I've also noted that my steam boiler pressure, which previously was steady at 1.3 at 255 degrees, is now 1.6, in the red at the same temp 255. So I turned it off.

Any suggestions appreciated.