Leaking Minima.

simonc

Probably 2 weeks ago my Minima started screeching when the pressure ramped to full pressure. Going a little coarser has eliminated it but was on my to do list to investigate.

A few days ago when using it, think I was flushing the steam wand, it tripped the electricity. I was investigating this morning and noticed that I now have water bubbling and hissing on top of the service boiler.

I’ll take the case off later to look but any pointers on what to look for and what to tighten or importantly not touch would be appreciated.

Could this be the opv? I am overdue a descale I think.

MediumRoastSteam

simonc Could this be the opv? I am overdue a descale I think.

That would be the safety valve or the vacuum breaker. Best to make a video of what’s happening when you get to open the machine.

What water are you using?

simonc

MediumRoastSteam third wave water espresso blend.

PortafilterProcrastinator

Also depends if it is leaking from a thread or from a (malfunctioning) part.

A video would be most helpful to see what is going on.

MediumRoastSteam

simonc thanks. Let’s see more when you do a video of the machine’s internal showing the issue.

simonc

MediumRoastSteam accidentally left m the steam boiler on yesterday and came down this morning after it had been on for an hour via smart switch to water hissing away on the top of the steam boiler. When I pulled it out to get the top off the were 3 small pools of water

And the steam boiler temp increased to 128c Vs set point of 125.

The biggest was under the steam boiler, it looks like water ran off the top and down the rear side. Not sure how the water got to under the brew boiler, if same leak and it just ran along a pipe or something else?

Water on service boiler

Could it be coming out of a release valve on top or should I try tightening some of the nuts?

simonc

Typically it’s behaving itself now. Thinking about it, it might hace been when I noticed the steam wand was putting out a lot of water into my cloth and so I ran it into a jug of water for maybe 30 seconds to stop any spluttering or weirdness.

Still think I should descale the service boiler just to be safe. Is it drain boiler, 1-2tbs per liter citric acid into tank, turn on let boiler fill? How long do I leave it in for before then draining and rinsing?

Thanks

simonc

Apologies to @DavecUK I’ve just realised it’s in the user manual!

simonc

So no more leaks but the screeching is back, is when I go slightly finer and push a shot past 40 seconds. You can hear it when it first ramps to 9.5 bar then stops as presumably it gets a bit easier through the puck, but the pressure doesn’t drop much.

If I were to run this 20g shot at 1:2 in 35 seconds it w normally doesn’t make this noise.

Any ideas. This has the Lelit quiet pump in it now.

Video

DavecUK

simonc Just slight “reeding” via the expansion valve, nothing to worry about, can happen on all machines with vibe pumps if it bothers you adjusting pressure up or down even 0.2 bar can often stop it. That’s a very tight shot…

simonc

DavecUK cheers. Yes I deliberately went finer to emphasise it, normally only get it when dialling in as would go coarser and it then disappears. Might try dropping it down to 9 anyway.

Or been tempted for a while to try the 5 bars that Store Street espresso do which I love, maybe now the time to play

CoyoteOldMan

simonc The other noise I thought I heard is the glass vibrating on the drip tray…

MediumRoastSteam

simonc - apart from you winning the prize for shortest video on coffeetime, 🤷‍♂️🙃😉 - it’s possible to observe there’s a lot of condensation all around it - so it must be the water is just finding its way there by gravity.

If the safety valve has blown - I can’t tell from the video, it’s to short - then this would make sense. It could be your sensor is corroded or covered with limescale given the water you use.

Worthwhile observing the machine without its covers - be careful as water and electricity combined with high temperatures could be very dangerous though. only touch anything inside with the machine physically unplugged from the wall, preferably cold.

MediumRoastSteam

simonc - run he machine with the top off and try to identify where the hissing steam is coming from.

At least that’s what you said:

simonc water hissing away on the top of the steam boiler

simonc

Haha thanks. By the time I got the top off the water had almost gone. Hadn’t realised it was quite that short though.

How would I tell the safety valve is blown? It’s only had Waitrose water in then recently TWW.

Again what bit is the sensor that I should check for limescale?

I’ll try running it with the top off so I can see little bits of water more easily

Thanks

Rob1

simonc It’s only had Waitrose water in then recently TWW.

Might have missed it but how are you using the service boiler? Always on? Steaming daily or multiple times per day? Regularly emptying via the hot water tap to refresh the water in there? Anything with hardness and alkalinity will scale in a service boiler eventually if you don’t have some kind of flushing routine in place. If not, descaling will be necessary.

simonc

Rob1 hi. Yes I use the service boiler a lot, and do occasionally forget to turn it off so it stays on all day (what I can now blame on recent late adhd diagnosis - subject of another post). I do also make long blacks and take water from the service boiler to refresh a few times a week and every month or 2 drain the service boiler and refill with water straight from the zero jug.

I did do a descale of it a few weeks ago after I first noticed this problem.

simonc

I’m back, 2 months with no coffee and I’m finally able to have some again.

Starting slowly and mixing in plenty of decaf

however 3rd time using it I had the same issue with water leaking out of the top of the service boiler. Video here. Hard to tell but I think it’s coming from the brass valve thing in the middle.

Also it was set to 125 but was showing 127 whilst spluttering.

I then set it to 120 and turned off for a few hours. When I turned it back on the service boiler got up to 128 then seemed to stop heating, well past its set point.

Is this a heating problem and steam/water is escaping through an opv or similar? I’m hoping it’s not a big part to replace

Also the steam I got from it was much wetter than normal.

DavecUK

We need to see a video as it gets up to pressure and before the swimming pool develops. It could be a very simple repair, requiring just a bit of PTFE tape, or youy might have to buy a safety valve (fairly cheap), could even be an earth wire problem.

Be good if you can remind me of the age of machine

simonc

DavecUK ok I’ll try but it doesn’t always happen.

It’s an early model, has the weight based water sensor (until I added the newer version anyway)

DavecUK

simonc Good handy to know, because if the boiler is just overfilling, there might be a simple solution.

The tests to do in logical order

make the video
When steam boiler is up to temp, switch off how much water can you get out of the hot water tap
take the case off and locate the very thin black water sensing ground wire from the Gicar box…photograph what it’s attached to.