# Gaggia Classic - OPV always opening



## SamS (Jul 17, 2020)

Hi everyone,

I recently ran into some problems with my Gaggia Classic pre 2015.

Anytime I start pumping (without a portafilter inserted or even when group head is taken off), the OPV opens and water flows back into the tank. The water flow from the group head thus only starts with a delay of a few seconds. I am under the impression that no water should flow back into the tank when no portafilter is inserted. The same happens when I turn on the steam switch. The OPV stays open and I can't get any pressure to steam.

I thought maybe the OPV is set too low so tried screwing it all the way in which should result in the 15 bars from the pump but the OPV still opens up when pumping and steaming. I have measured with a pressure gauge and I cannot get anything above 7 bars.

On another forum, I read that it might be scale in the OPV so unscrewed the parts, descaled and cleaned them but that didn't help. Everything inside the OPV looked fine and came out without a problem.

I am running out of ideas now what could fix this. I also couldn't find any holes that would let in any air in the hose from the tank to the pump and the tube from pump to OPV.

Has anyone had a similar problem and could share some wisdom? Thanks!


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## kozesluk (Apr 28, 2019)

OPV plunger rubber seal deteriorated. Replace it.


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## SamS (Jul 17, 2020)

Hi, is this the part you are referring to on the left?









I double checked with mine and mine does have a hole in the middle...









Any idea where I could get a new one or how to fix it?


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## kozesluk (Apr 28, 2019)

you can pop the seal out and put it back the other side up, sometime it works...


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## MrShades (Jul 29, 2009)

It certainly appears to be the same as the valve cap in the new plastic OPV - which is a pretty cheap spare part. Might be worth trying it if you're really stuck.

If you measure it across the flats and also the thickness of it then I'm happy to compare with the one in these valves.

https://www.ebay.co.uk/itm/154006309784

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## L&R (Mar 8, 2018)

Ok now is the time to check your 3-way valve


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## SamS (Jul 17, 2020)

Thanks for the replies.

I talked to a few repair shops and they all said that they only sell OPVs, no spare parts for an OPV. They also said it's a pretty rare for this to happen. In the end I replaced the whole OPV and the machine is now working fine again.

I still measured the old valve cap (is that what it's called?) and maybe MrShades can compare it so anyone else who might have this problem in the future can fix this a lot cheaper than I did...

It's ≈9.5-10mm wide across the flats and 5mm thick.


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## ratty (Sep 22, 2019)

SamS said:


> Thanks for the replies.
> 
> I talked to a few repair shops and they all said that they only sell OPVs, no spare parts for an OPV. They also said it's a pretty rare for this to happen. In the end I replaced the whole OPV and the machine is now working fine again.
> 
> ...


 That would be good info to have @MrShades

Such a waste scrapping an OPV for the sake of a seal.

I took a punt on a used one on ebay the other day. Advertised for £25 initially then it got reduced by £10 to £15 (+£3.50 P&P) so I bought it.

Always good to have a spare.

Luckily it stripped down ok with a pre soak in GT85 overnight.


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## MrShades (Jul 29, 2009)

Looks like the new one is slightly smaller - at 7mm across










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## kozesluk (Apr 28, 2019)

you can literally punch a seal like that from anything soft (around SHORE 60-80 hardness would be nice) and resistant to water. NBR, Viton, even Silicone... you can even use a scissors to cut down to size a larger seal. and even the thickness doesn't matter as much as it might seem, it's usually around 4 mm but depends... shops sell whole spare OPV because they make much better money on replacing whole (also, it's faster) than **ing around with seals... and to say that it is rare for a seal to fail? ** me running, what a bull****!


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