Ponte Vecchio Export problem

A haven dedicated to manual espresso machine aficionados.
SeanOnly
Posts: 7
Joined: 8 months ago

#1: Post by SeanOnly »

Hello,

I bought an Export off ebay a couple of weeks ago and things were going well. However the group is now filling with steam. I'm assuming this is an issue with the gaskets. When I pull the lever a lot of steam comes out before any water. Has anyone else experienced this?

Thanks,
Sean

Nunas
Supporter ♡
Posts: 3636
Joined: 9 years ago

#2: Post by Nunas »

I believe your machine is similar to my Zacconi. Several things can cause this. If you don't have enough water in the boiler, the end of the dip tube can draw steam instead of water, as it does not go all the way to the bottom. If you've taken the group off and not properly tightened the dip tube, it can draw steam where the tube enters the back of the group head. Ditto if the dip tube develops a crack (rare). How's your steam pressure? If the pressure/temperature of the boiler/group is very high, then you can get a lot of flash boiling, similar to what happens on an HX, which is why HX machines need a flush prior to pulling a shot. This could be from leaving the machine on for prolonged periods or a bad pressurestat. You can test the group temperature and the boiler temperature with an IR thermometer, but put some black tape on the spot where you're sensing, for a more accurate reading. On my machine, I added a silicone gasket between the group and the boiler to minimize group overheating.

User avatar
baldheadracing
Team HB
Posts: 6178
Joined: 9 years ago

#3: Post by baldheadracing »

I'd remove the group and check the dipper tube. I have had a dipper tube crack shortly after shipping - in a well-used machine.

(I'm assuming that you have enough water in the machine!)

ETA: not a valid diagnosis given the video posted afterwards.
-"Good quality brings happiness as you use it" - Nobuho Miya, Kamasada

SeanOnly (original poster)
Posts: 7
Joined: 8 months ago

#4: Post by SeanOnly (original poster) »

Thanks for the suggestions.

I definitely have enough water in there. The group does feel very hot and there's tons of steam out of the wand.

I don't have the tools to get the piston out unfortunately so I'll have to wait.

I let the machine cool and tried another shot after powering it up and again I got a burst of steam while pulling the lever.

User avatar
peacecup
Posts: 3646
Joined: 19 years ago

#5: Post by peacecup »

Sounds like the pstat may be set too high.

Are you getting any hissing from the over-pressure valve? If it is a used machine the opv could be stuck. WITH THE MACHINE OFF AND NO PRESSURE IN THE BOILER you can test the opv by pulling up on the stem with a pliers
LMWDP #049
Hand-ground, hand-pulled: "hands down.."

SeanOnly (original poster)
Posts: 7
Joined: 8 months ago

#6: Post by SeanOnly (original poster) »

I think my opv valve is a bit different to others after a Google image search. It's adjustable and I opened it up a bit and I can hear a intermittent hiss as its coming up to temperature. It still hasn't fixed the issue though.

I have attached a video of whats happening.

espressotime
Posts: 1748
Joined: 13 years ago

#7: Post by espressotime »

You are running very high boiler pressure.It's not steam.It's steaming water.
Buy a gauge and attach it to the steampipe and set your pressostat to about 1.1

User avatar
peacecup
Posts: 3646
Joined: 19 years ago

#8: Post by peacecup »

That looks pretty normal for a machine that is fully warmed up, although a bit on the hot side. I would unplug the machine, open the bottom compartment, and turn the pressurestat down a at least a half turn.

If you are careful and ensure that the base stays dry you can run the machine without the bottom plate while you adjust the pstat. Just be sure to unplug whenever you are accessing the pstat where all wires are
LMWDP #049
Hand-ground, hand-pulled: "hands down.."

User avatar
peacecup
Posts: 3646
Joined: 19 years ago

#9: Post by peacecup »

I agree with espressotime that the pressure is too high. I run mine even lower that his, round 0.9-1.0 bar.

It is difficult to tell without a pressure gauge but starting by turning the pstat down 1/2 to 1 turn will probability get you in the right range
LMWDP #049
Hand-ground, hand-pulled: "hands down.."

SeanOnly (original poster)
Posts: 7
Joined: 8 months ago

#10: Post by SeanOnly (original poster) »

OK I'll try turning it down. Thanks lads