# Rocket Giotto - Brew pressure gauge going crazy



## Bainbridge

Hey,

So I bought this Rocket Giotto about 6 months ago from @Hasi. Had a few issues during delivery which caused some damage to some small components. Fortunately @Hasi was on hand to help me diagnose and replace the relevant items. He then got me a refund on the replaced components. All very much appreciated.

The Giotto has been behaving itself apart from when I turned up the Brew pressure. Hasi was running it at 6 bar, but when I pushed it up to 9 bar the Brew pressure gauge totally flips out.

I borrowed a porter filter guage from a friend and the brew pressure there was solid as a rock, so I don't really know causing it.

I've done a video where the water runs through without coffee in a standard basket, and then one with a blind filter.

Any help would be much appreciated!


----------



## Inspector

dont know if it is related at all but gaggia behaves similar when there is air in the system.


----------



## mctrials23

Air in the pipe that feeds the manometer I think.


----------



## Bainbridge

Think I've fixed it ?


----------



## Inspector

How?


----------



## Bainbridge

It actually sorted itself out when I descaled. Not sure why that would have fixed it!


----------



## DavecUK

Bainbridge said:


> It actually sorted itself out when I descaled. Not sure why that would have fixed it!


 The expansion valves can resonate, sometimes a very small change in pressure can fix, sometimes descaling if it's made worse by scale.


----------



## Bainbridge

DavecUK said:


> The expansion valves can resonate, sometimes a very small change in pressure can fix, sometimes descaling if it's made worse by scale.


 Another good reason to descale regularly!


----------



## Bainbridge

Soooo

I took apart the E61 mushroom yesterday to make sure it wasn't too scaled up. It was actually fine, a few bits here and there but all seemed ok.

I cleaned it up and put it back together, then pulled a shot. The fluctuations on the brew pressure gauge are back. Much much less, but there is the annoying ticking when up to pressure.






Any ideas @DavecUK? Descale again?


----------



## DavecUK

DavecUK said:


> The expansion valves can resonate, sometimes a very small change in pressure can fix, sometimes descaling if it's made worse by scale.


 above


----------



## Bainbridge

Ok so I descaled again today. All been flushed through and I was interested to see if the pressure guage would still be doing it's vibrating.

Now it seems to be working ok but now when the pressure rises there is a very strange noise:






Sorry to keep bothering you @DavecUK but do you have any idea what that could be, and how I might go about fixing it?


----------



## DavecUK

Yeah, quite often the expansion valves can squeak and chatter, like a musician blowing a reed. I would think a new expansion valve might not do it as the pad would be uncompressed and new. Have you located where the sound is coming from, usually with the case off is the best way?


----------



## ISCM

I get that same sound and I got that from new.
There is no scale in my area (I never have to descale my kettle), so it can't be that.

I would not even worry about that noise and make sure that you just keep your machine descaled.

It may be worth investing in reverse osmosis filtration.
That would improve the taste of your coffee (and tea).

A friend of mine installed that in his bar in Menorca where the water is undrinkable (it wont kill you but tastes horrible plus can give an upset stomach). Now the water is pure, clear and can be used for his espresso machine direct.
All the other bars that I know in Menorca use containers of water brought in for making coffee, but his coffeé is the best.


----------

