Issue with San Remo Treviso HX machine
I'm having a fair bit of trouble with my San Remo machine. For a while I've been struggling with very thin, acidic espresso with either no crema, or one that dissipates very quickly.
A while ago, my machine had a bit of a phase where the pressurestat would click on and off like crazy and after a minute or so, the machine would jump in pressure drastically before easing off slowly down to 0 bar. This eventually stopped as the machine seemed to unblock somewhere/etc.
The flow rate of the machine is fine running at about 230ml water/per 30 seconds without a portafilter attached. The pressure sits at approx 9bar when brewing.
However, when steaming, the pressure drops and sits around 6bar.
I've tried grinding finer to the point where it begins to choke the machine a little which still results in this espresso. I'm using a Mazzer Super Jolly Electronic with new burrs. This also occured when I had older burrs in place.
I had a compak k3 prior to this which also had the same results, so I can rule out the grind as a possible variable. I had absolutely no issue with my Silvia and the K3, so it must be a machine issue!
I'm also using an 18gram VST basket, dosing between 20-21 grams (depending on the coffee) and weighing to the nearest 0.1 of a gram.
Any ideas? Thanks in advance.
Also, my Ulka EP5 vibration pump in the machine is quite loud.
I'm thinking the pump might have had it.... When I dispense hot water, the boiler pressure drops dramatically. I'm thinking the pump works okay when it's not under pressure (ie the flow rate being fine without a portafilter in place) but it might be struggling to keep up with any sort of load on it. Could this be the issue?
Another bit of info:
With the blind filter in, the pressure reads 10bar on the dial when the lever is activated. (to clarify this is an E61 group machine).
I also recorded 30ml of water in 12 seconds which returns from the deaerator and into the drip tray, which is apparently what it should be doing according to this video: https://www.youtube.com/watch?v=kEl-uNOC1P4
Ants1ssa more info about your Bean / Roast? Age?
Machine - age?, Maintenance schedule? Water Filter? Area of Oz?
Some areas are particularly known for their water quality or lack of?
When you say you dose a VST 18 at 21g. I don't have an 18g but a 15g.
and it doesn't up dose to that same % level with my E61 group.
Have you removed the G/Handle after locking it away to see whether at this dose
the puck is being impacted by the shower screen?
Meaning fractured puck can = fast loose shot with little flavour next to no crema.
A while ago, my machine had a bit of a phase where the pressurestat would click on and off like crazy and after a minute or so, the machine would jump in pressure drastically before easing off slowly down to 0 bar. This eventually stopped as the machine seemed to unblock somewhere/etc."
I would be back tracing this. Are you sure / (or iffy ?) that your getting both pressure and temp at the grouphead that is within spec?
To provide some more info:
Beans: I use Sensory Lab, Industry Beans, Everyday or Cartel. They all supply very very good quality coffee. The beans are usually a light/medium sort of roast and are generally anywhere between 2 days to 10 days old.
Grinding on a Mazzer Super Jolly fitted with new burrs. Burrs spin well and bearings are not loose. Produces really fluffy, nice grounds (although it does clump a bit). I use the WDT distribution method to ensure good distribution.
Machine is 6 years old, but was in storage up until recently. I fitted a new one-way check valve (sits before the solenoid) because it had an old, cracked one in it.
I only ever use R/O water and I'm in Victoria, Ballarat.
I back flush usually every 2-3 days and do a chemical back flush fortnightly.
The pucks are usually fine, no cracking and generally not sloppy. I've tried grinding finer and dosing less, but the same result occurs.
Using a Pesado 58.5mm tamp that fits perfectly.
I'm not sure how to check pressure & temp at the group head to be honest. How might I achieve this?
Just an update:
- Ordered a new pump which should arrive in a few days
- Attempted to take out expansion valve for cleaning. It snapped in half with barely any force, so I can safely assume it needed replacing too.
Now that I think about it, a fairly strong stream of water was being dispensed from the valve during shots and during backflush. Hopefully some new parts fix my issues