Hi all,

Anyone got an idea? My 6 year old ECM Giotto premium has just been serviced and got a new control box. All seems ok, until the machine has been on for 45 minutes or so. Before this time the machine works ok. After that time, the pump won't start, not when pulling the lever, nor for filling the boiler. If the boiler is filled, the boiler is heated and pressure remains. I've opened the machine and checked all wires / connections, and they all seem ok. Can it be the control box overheating? The original control box was wrapped in insulation, the new box isn't. Or maybe it is something else?

Thanks in advance!

Best regard,
Maarten.

Your pump IS LIKELY equipped with a thermal switch, also known as a Klixon, as shown in the pic below circled in red.



More than likely Mr. Klixon has decided to "call it a day" early. You can temporarily bypass same and replace at your earliest convenience.

Hi Eric,

Thanks for the info. Sounds like this must be it. Also, my Italian car had the same problem last month.... A sensor on the crank decided to stop working as soon as it reached operating temerature. I could have known...

One last question: bypassing is taking it of, or short circuit it? I'll report back on the outcome.

Cheers,
Maarten.

It is in series with one of the leads to the pump so . . . just remove it and reconnect the pump.

Hi Eric,

Thanks for the drawing, this is just what I did after looking at it. Sorry to say, this isn't it. After taking the switch out, the machine was on for 45 minutes or so with the cover off. After putting it together, putting it on the counter all looked fine, but 5 or 10 minutes later, no pump. Turning it off for 5 or 10 minutes, I get enough time to pull a shot. Any other ideas? The pump also doesn't work for refilling the boiler at that time, btw.

A completely different question: when counting the time for a shot, do you start after turning the pump on, or when the coffee starts to flow in the cup?

I much appreciate your help!

Maarten.

Timing for a shot (not necessarily recommended) should begin when you lift the lever.

As regards the pump not working, the only other sensor that comes to mind is a white wire connection to the "mini-reservoir" which the main tank dispenses into. This white wire achieves continuinty to ground when there is water present. Temporarily make up a jumper wire such that this white wire is always grounded.

The grounding activates a relay within the control box which, in broad terms, allows operation. I say "broad terms" because, IIRC, on some machines it knocks out the heater and the pump and on others just the heater. The fact that your control box was replaced potentially complicates the situation. What was the reason for replacing the control box?

While there is certainly no obvious correlation between the white wire I speak of and machine "heating up", it is the only other sensor I can think of that removes power from the pump.

Another suggestion is to write down the number on your old control box (if available) and that on the new one and the serial number, if any, of your machine. The control box numbers would be something like RLO xx/xx/xx/x .

Hi Eric,

Sorry to take so long to answer. I just couldn't find the time looking into my espresso trouble, and I received my Mypressi a couple of weeks ago, so that took up some time as well (and made the need for the Giotto a bit less urgent) .

Anyway, I don't have the old control box around anymore. I threw it away because it looked scorched and convincingly dead. The machine doesn't seem to have a serial. The new control box has serial RLO 1E/1S/4C/F. It does seem to switch both the pump and the heater: 2 white wire go into connectors 4 and 5, one has a circle with a P in it (pump?), the other is a rectangle with divided from two opposite corners with the text E.V. LIV (or LV) next to it. I remember the shop owner that fixed it saying this one was 24 V output i.s.o. 220 for the old one....??

Anyway, I'm not sure which white wire you mean. Is it the one that runs into the little box shown in the picture? Doesn't look like a mini-reservoir, but I could be mistaking of course.... It does run into the CB connector 4, which is the pump anyway.... Just want to be sure though...


Thanks again,
Maarten.

White wire as shown in the below pic - green arrow, lower left.



Send me an email at my address below my sig.

Here is a pic of your controller and my understanding of how it works - obviously different voltages but that is taken care of by the transformer on the control board.



The K2 relay is activated by the autofill circuitry as it starts the pump and opens the boiler fill solenoid simultaneously.

The K3 relay controls the power to the heating element as a result of control input from the pstat.

The K1 relay IS NORMALLY made active when the water level in the baby reservoir is OK but, in your particular case, (because the baby reservoir is not fitted) is likely made active when the large reservoir has a normal level. If K1 is not made active, the pump and boiler fill are inoperative but the heating element can still work.