# Giotto pump pressure problem



## SimonN (Feb 4, 2016)

Hi all,

I've got an issue with my Giotto Evo where the brew pressure seems to fluctuate but I think I may know what the problem is. Is anybody able to confirm my understanding?

As soon as I start brewing I get an immediate small drop in my boiler pressure (enough to kick the element in every time). I'm also finding that the brew pressure is dropping slightly throughout the brew (these are things I remember noticing before).

I am thinking it could be the boiler fill solenoid that's playing up and not sealing or is weak, so that it's filling the boiler slightly at the same time as passing water through the group.

Is that possible? I'm making the assumption that the pumps default is to pass water through the group, whereas the boiler fills if the solenoid is activated.

Does it sound like I'm on the right track?

For info, my machine is plumbed in through a filter and is scale free. I've tried running a citric acid solution through just in case but it has made no difference 

Any help would be appreciated

Cheers

Simon


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## DavecUK (Aug 6, 2013)

SimonN said:


> Hi all,
> 
> I've got an issue with my Giotto Evo where the brew pressure seems to fluctuate but I think I may know what the problem is. Is anybody able to confirm my understanding?
> 
> ...


From what you have described, no you are not on the right track.

1. Normal as cool water is going through the HX pipe that passes through the steam boiler, so a cooling of the water in the steam boiler, subsequent pressure drop and kicking on of heating element is the expected behaviour

2. No, if it was the pressure in the boiler would probably rise not fall and other problems such as boiler overfilling would result (unless you steam or draw water after every shot, which would mask it). If it was leaky when not pulling a shot, this would give yet other symptoms (including eventual boiler overfilling)

3. Yes

Why don't you try a shot against a blind filter and see what happens?


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## SimonN (Feb 4, 2016)

DavecUK said:


> From what you have described, no you are not on the right track.
> 
> 1. Normal as cool water is going through the HX pipe that passes through the steam boiler, so a cooling of the water in the steam boiler, subsequent pressure drop and kicking on of heating element is the expected behaviour
> 
> ...


Thanks for the reply Dave, I was hoping you might respond!

Interesting about point 1, thanks, maybe I've just never noticed it in that past and paranoia is getting the better of me 

I do always draw either steam or water after every shot (we drink flat whites or Americano's (lungos) so masking the problem is possible. Other things I think I have noticed, but again this could be paranoia, is that the brew pressure gauge climbs to about 8 bar as the boiler heats up. I'm fairly sure it didn't in the past, that said it drops instantly when I lift the brew lever.

I probably should have said but a few weeks ago the boiler clearly overfilled, and operating the pump made the boiler pressure gauge go crazy. At the time I thought it was the boiler fill probe which is what led me to descale. However, I can't help thinking the machine fixed itself rather than it being anything to do with the fill level probe, otherwise I think the boiler would have being trying to fill itself constantly (which it wasn't)

I did actually put a blind basket in yesterday to backflush, if anything the pump pressure seems inconsistent, it's anywhere between 9.5 and as low as 8 - the pump has been steady at 9 bar for the last 6 months.

Help!!!

Cheers

Simon


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## DavecUK (Aug 6, 2013)

Age of machine?


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## SimonN (Feb 4, 2016)

DavecUK said:


> Age of machine?


Err, I'm not sure, I bought it used from the forum. It's a Giotto evo 2, does that help?


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## DavecUK (Aug 6, 2013)

SimonN said:


> Err, I'm not sure, I bought it used from the forum. It's a Giotto evo 2, does that help?


Not really but if it's 6 or 7 years old, perhaps it needs a new pump


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