Replace Linea Mini Grouphead solenoid

schander

So a couple weeks ago I notice a funny sound from the mini, upon examination i was hearing a bubbling tracked it down to the water reservoir pipe was pushing water in the tank. I switched the machine off let is cool down and then back on, everything was fine.
Ruth at La Marzocco said on of the engineers thought it might be check value, i purchased Page 14 number 5 from Linea Mini Parts
A couple of days later the group head stopped delivering water. There was water in the steam wand and water tap.
I read around a possible solution was that the gicleur was blocked. Ordered one and replaced it using this guide
Everything was fine for a couple of days then the water stopped again. Reading more, it could be the solenoid valve.
Having order a solenoid and washers i set about replacing the solenoid this morning.
Looking around the group head I noticed that there had been leak as can be seen in pic 1 here: Pics
Pic 2 Shows the fix for the bare wires i found
Pic 3 Shows the top missing from the stats on the group head
Pic 4 Old/New Solenoids
Pic 5 Tight fit on the fixtures Pages 22 number 16 per the parts catalogue above
Pic 6 Disater strikes the copper pipe flare give way. Page 22 part 19 per the parts catalogue above
Now I have to wait until espresso solutions have the part back in stock. Half tempted the redo the flare myself however given exacting lengths it might not be worth it.

Anyone got any thoughts?
What’s the best way to replace the wires that i taped up? Replace the heating cartridge page 26 number 19
Do i need to replace the stat at the top? These are not listed in the part catalogue!

Am I barking up the wrong tree here? Any tips greatly appreciated.
What’s really annoying is that it was only serviced in July!

Best Regards
Satpal

DavecUK

This is going to need a longer reply…as i have never seen inside a Linea Mini, but it looks simple enough. It would help if you had some better photos rather than the close up guess what this part is, so I could see what’s what.

I suspect the machine had multiple problems, but in fixing one you found others.

For future reference, the solenoid coils rarely fail and you can buy just the nucleus for a few bucks…keeps things cheap….
For the wires, remove the spades, slide some heat shrink up…shrink it then replace the spades…or just replace them, Then find a grommet for that hole, so the wires don’t abrade again (if you think that’s what abraded them.
Is the snapped fitting just a solenoid vent (drain), pip as you said?? because to me it looks like the pipe to the water tap fitting. Regardless, you may be able to replace it with good quality PTFE tube…which is what I would do. you can buy the right fittings to put each end which then clamp the tube properly
Why do you want to replace the heating cartridges? These could well be a press fit, requiring boiler removal and a tool.
The stat at the top can probably still be reset by pressing with an insulated implement and the machine off, of course. Theres 2 limit stats for belt and braces. If you do replace it, it should be expensive.

This is a solenoid nucleus…

Norvin

The nut clamping the copper tube to the solenoid in the fifth picture looks like it is cross threaded. It may be worth checking it for leaks before putting the covers back.

DavecUK

Norvin The nut you are referring to is the one to the group head! You’re right it does look cross threaded.

schander

@DavecUK thanks for your reply. I will try and get wider pics, have closed it up for the time being less mess, less headache if you know what i mean. I did list the page and part numbers as per the parts catalogue i linked to.
Noted about the nucleus.
I think shrink wrap will be good enough, I’m concerned as to why they braded.
Yes the snapped fitting is just a drain to the drip tray. Sorry but I don’t fully follow you thoughts about PTFE tube and how i could clamp it.
On initial look I can’t find the heater cartridges/stats to buy

@Norvin thats a good catch - I’ll order a replacement.

Thanks for the help

DavecUK

schander Noted about the nucleus.
1. I think shrink wrap will be good enough, I’m concerned as to why they braded.
2. Yes the snapped fitting is just a drain to the drip tray. Sorry but I don’t fully follow you thoughts about PTFE tube and how i could clamp it.
3. On initial look I can’t find the heater cartridges/stats to buy

I well the braiding was under the insulation…that’s how wire under insulation looks..normally it’s copper though are both those wires attached to the same terminal?
you buy an adaptor fitting that tales PTFE tube…the accessories shop should guide you…
Why do you need the heater cartridges? and if you can’t find the stats they may be pressed in (something you might find hard to do at home…have you tried to remove one, if it’s failed?

What is the history of this particular machine, you said it was serviced back in June I think? Did you purchase it used?

schander

@DavecUK thanks for the reply.
Both the wires are attached to the same terminal. and there is the equivalent on the other side aswell.
I will look into getting the PTFE tube and .
Not tried to remove the cartridge. Looking at the parts catalogue it appears that they are inserted and held in place via screws at the front and back of the brew assembly. Not entirely sure how the cartridges can be checked for failure.

History of the machine is:
Bought August 2019 from a coffee roasters, who probably had it for a while. They say they only used tesch ashbeck water.
It was serviced in July by ESTech as per the recommendation of La Marzocco

Cheers
Satpal

DavecUK

schander

Both the wires are attached to the same terminal. and there is the equivalent on the other side aswell.

I will look into getting the PTFE tube and .

Not tried to remove the cartridge. Looking at the parts catalogue it appears that they are inserted and held in place via screws at the front and back of the brew assembly. Not entirely sure how the cartridges can be checked for failure.

History of the machine is:
Bought August 2019 from a coffee roasters, who probably had it for a while. They say they only used tesch ashbeck water.
It was serviced in July by ESTech as per the recommendation of La Marzocco

I guessed that might be the case. Probably just taping them up properly…will be fine as a short term fix.
That should sort the drainage
If it were me doing the heater cartridge, I would do it 2 possible ways, either with heat sink compound (non drying), or with a press fit. The screw would simply be to keep them in place/ensure their are in far enough

The problem with heat sink compound, is it invariably dries, you might be able to use a liquid metal compound, buit there is always corrosive reaction worries, as I assume the head block is made from Aluminium with a steel wet liner (that’s how I would probably do it with that design) The better way is to press them into an extremely well-designed brass holder that is a press fit into the group, or similar. I had a look at a photo and I think they are put in with heat sink compound.

Either way, removal will probably be a destructive process for the heater and I still have no got to the bottom of why you want to replace it. I will ask again, do you think a heater has failed. To test the heater, you can simply use a meter set to the resistance scale and see how many ohms it reads. If it’s burnt out, it will be open circuit…if it’a a direct short, it will have either tripped a fuse inside the machine or your electrics. There may have been some problem, because how did that limit stat button get broken?

The history doesn’t state the date of manufacture, which will be on the rating plate of the machine….it’s handy to know how old it is, as that guides maintenance and fault-finding.

Until I see some larger pulled back shots, I can tell nothing else.