Hey Folks

So I have a 2004 Pasquini Livia 90 semi automatic (newer models) that I bought from the original owner maybe about 3 months ago. Anyways, after purchase, it started to overheat and long story short, the seller agreed to buy a pressure stat. I install it and the unit operated well for about 2 months.

Recently, i noticed that sometimes but not always, it has started to overheat after I pull a shot and the heating element does not shut down unless I turn off the machine and let it cool for about 2-3 minutes. After I do this, the heating element turns on if the boiler is below 1.3 bar and once it hits that pressure, it turns off as intended (normal operation).

My guess on the issue is one of the following:

1. Bad relay? somehow gets stuck on the on position?
2. Bar pressure stat, even though it got replaced recently?
3. Boiler overfill caused by a sensor or bad solenoid valve?

Any suggestions will be appreciated.

What type of pstat is it?

I have a new XP110 in my old machine and had to unscrew the adjustment screw and fiddle with the pin to stop it from sometime overheating as you have experienced. its worked.

My machine does not have a relay so I have no experience with them, but my guess is that this is not the issue. If it is, I would except a rarely "stuck" relay to stick in the off position as a result of oxidation, but its not my first thought.

Also, any idea on scaling inside the boiler? you might want to dissasemble the pstat tube and give it a good vinegar soak, it might be partially clogged?

KEEP US POSTED!

I have a Livia 90 which had failed due to a fire within the unit in the hands of the original owner who left it on 24/7.
The relay had melted, and so also did the teflon dip tubes coming down into the boiler from the water inlet and outlet.

The relay is definitely suspect, as is the pstat. A third place to look would be the controller box, they can work ok when cool and become erratic when hot.

bengee wrote:What type of pstat is it?

I have a new XP110 in my old machine and had to unscrew the adjustment screw and fiddle with the pin to stop it from sometime overheating as you have experienced. its worked.

My machine does not have a relay so I have no experience with them, but my guess is that this is not the issue. If it is, I would except a rarely "stuck" relay to stick in the off position as a result of oxidation, but its not my first thought.

Also, any idea on scaling inside the boiler? you might want to dissasemble the pstat tube and give it a good vinegar soak, it might be partially clogged?

KEEP US POSTED!

The pressure stat is the XP110 and I did replace it and it doesn't overheat as often as before with previous one. There seems to be various models for the XP110 pt, some you can control from 0.5 bar-1.5 and others from 1-2.5bar but I dont think it matters since my target pressure reading is about 1.3 bar. I have ordered a new relay to see if that fixes the problem but if not, my next step is to remove the pressure stat copper lines and leave them on cafiza and reset the pt & adjust.

I did descale the boiler when I bought the machine so i am not sure if it needs it again. The level probes looked very clean post descale.

Thanks for your help.

hankbates wrote:I have a Livia 90 which had failed due to a fire within the unit in the hands of the original owner who left it on 24/7.
The relay had melted, and so also did the teflon dip tubes coming down into the boiler from the water inlet and outlet.

The relay is definitely suspect, as is the pstat. A third place to look would be the controller box, they can work ok when cool and become erratic when hot.

If I am not mistaken, on the Livia 90 from what I have read on other discussions, the heating element is only controlled by the pstat and the relay. Since the current pulled by the HE cannot go through the pstat mini switch, then a relay is needed. The controller box is only used for the auto fill function of the machine but I could be wrong.

Thanks for your suggestions

Power to the heating element comes from closed contacts in the relay.
The actuating coil in the relay receives power from the closed contacts in the pstat.
Pstat power comes from the control box, but only if there is sufficient water in the reservoir (covers the wired button in the side) and enough water in the boiler to ground the longer probe within.

Neto wrote:The pressure stat is the XP110 and I did replace it and it doesn't overheat as often as before with previous one.

This is EXACTLY what happened with mine. The pstat was really old and the boiler kept overheating, so I swapped for a new XP110 (the original PSTAT was of another type and era). The situation improved to a great extent but still sometimes overheated. I was confused. So i de-scaled the pstat tube once again, this time with vinegar, and found some golden tidbits here on HB from a few knowledgeable people who confirmed that the XP110 can and does sometimes fail (closed) NEW FROM FACTORY. They suggested it needed to run for a while and that things would improve. Others suggested playing with the pin as I mentioned earlier. Well I did both (play with pin and wait) and the situation has cleared.

If you are right and the LIVIA 90 heater circuit bypasses the Gigar control box as does in mine, they yes, I believe you are right, the control box should have nothing to do with your problem.

The micro switch in the XP110 is rated at 15 amps, and directly handles the heating element current in many machines, such as the La Pavoni.
In the Livia 90 they only handle the relay actuation current which is much less.

As you are already doing, I would try the easy stuff first (listen for the relay clicking, isolate the pstat, etc.); these would be the least expensive.
But also pull the reservoir wire which leads to the controller box (or just run the level down) and make sure that the heating shuts off.

Should you determine that the controller box is the culprit, my advice would be to contact JPBoyt on this forum, who repairs these and has many happy customers, including me.

Failure of the control box would normally be a factor in failure of the boiler to heat, not overheat.
It is unlikely to be the problem here, as the pstat will normally open the circuit.

hankbates wrote:Power to the heating element comes from closed contacts in the relay.
The actuating coil in the relay receives power from the closed contacts in the pstat.
Pstat power comes from the control box, but only if there is sufficient water in the reservoir (covers the wired button in the side) and enough water in the boiler to ground the longer probe within.

That makes sense, thanks!