Tuesday, December 23

How to service or replace the brewing unit and plumbing on a Jura coffee machine and other fixes

While a neighbour has spent years repairing his Morris Minor car, fixing my coffee machine became a task of similar hobby proportions. After several weeks research I have an as-new machine with parts costing £100 - which is much less than £1200 for a new machine. 

In the UK it is assumed that if you can afford the BMW of coffee machines, you can afford someone who can fix and service it too. Read on and you could clean and repair your Jura coffee machine for £5 (for new 'O' seals). I hope the following saves someone the weeks I spent dismantling and reassembling a Jura coffee machine.

Summary of costs to date
Machine new £800
Replace brew unit £80
Replace cracked water tank £12
Replace broken metal frother arm with other small parts £15
Replace thermoblock, I and F connectors and membrane regulator £67
Spares https://juraproducts.uk/spare-parts

UPDATE 2015: Replaced some parts I should have replaced ages ago
With 16,000 cups now made the leaking from my 2004 Jura F90 was getting serious. I contacted UK Jura spares (below) to replace 'o' rings in numerous connections below the coffee grinder unit. I tried to remove and renew the connections to the thermoblock (heater) but they were so corroded that the heater also needed replacement. Overall the heater and new Teflon connectors cost £67 but nothing leaks anymore. This included the membrane regulator unit after the pump (at the front bottom of the machine) which I heard is notorious for leaking and has been modified.

UPDATE 2014: If the Jura touch panel is unresponsive or erratic 
After doing my first Jura service below, the machine would make coffees at random and a mess was the result.  The touch screen was also unresponsive at times. This may have been a problem I caused while dismantling but now it's fixed. It works when left to dry. And thanks to a forum post on a German site, it was suggested that steam can get behind the touch panel and the solution was to put plastic film (or card or shirt collar packing) horizontally beneath the panel to isolate it from the steam from the coffee dispensing area. I hope this works for you as it did for me.

UPDATE 2014: service the coffee grinder the easier way
You don't have to take the grinder to tiny pieces to service it. Some videos show you the entire dismantling but that may be unnecessary if you just want it cleaned up like new. On the Jura F90 you'll need to remove the top panel (see first bit of dismantling below). You'll see the coffee bean hopper held in place by two vertical screws. Go at them gently with a torx screwdriver bit else you'll break a fixing point. Note the position of the consumer grinding adjuster. Hoover excess beans. Lift the hopper clear. Clean the central silicone seal. Note the position of the big outer cog wheel which is the grinder adjuster. Turn this anticlockwise and you'll be able to remove the outer grinder wheel and clean up. If you're just wanting to clean it, don't loosen the central grinding wheel. Instead see this video, where the Saeco has a similar grinder.  When tightening up the two hopper screws after reassembling, don't over tighten.

UPDATE 2014: the plumbing leaks
See more recent update for a more radical repair. My F90 machine leaked and messed up a wood worktop. Most of the damage was due to emptying the grounds and drip tray. However, there was some leaking from inside. See below the bit about dismantling to remove the side panel (coffee grinder side) and access the pump and tubes. The tubes are plastic and held in place by a wire clip. You may now be able to spot where the leaks are by the scale. It may be enough to remove a wire clip, withdraw the tube and its brass collar. Inside there's a tiny 'o' ring seal to replace. Push the tube and collar back in firmly and add the clip.

The brewing unit can be the cause of Malfunction 8 

The brewing unit (= brewing group - Brüheinheit) collects the ground coffee; infuses it with water and ejects a plug of used grounds. A number of different brands are made by one Swiss firm. The brewing unit is almost identical on around 50 different Jura; Krups and AEG coffee machines. In other words, the guts of all these machines is often similar. The attachment places are similar; electronic garnishing (display; control programme and buttons) differ.

 video comes from http://www.coffeemakers.de/

The Jura Impressa F90 - background

This model occupies the middle part of the Jura range (which compares to the top of everyone else's ranges). It has a single water heater which means that it can make coffee or steam but not both at the same time. This isn't much of an inconvenience. The machine appears to know when it needs a clean; descale or empty.
  • The 'Empty  grounds'; 'Descale' and Clean machine' messages simply derive from counters; the 'Tray Missing' message comes from a microswitch. 'Fill Beans' appears if no coffee powder arrives in the brewing unit - though the sensor is probably in the grinder. The 'Fill water' message is triggered by a microswitch and/or a sensor in the plumbing. What you experience is not entirely spoofed intelligence and works well.
  • When you see the message 'Clean machine' you respond by holding the Maint. button until what to do appears on the display. The machine cleaning cycle cleans the brewing unit and coffee outlet only. 
  • The descaling cycle cleans the boiler; pump; valve; steam nozzle and probably the inlet nozzle at the bottom of the brewing unit. I never use a Claris filter since our water is chlorine-free. When you see the message 'Machine scaled' you respond by removing the water tank and turning the machine on by holding the Maint. button. What you must do to descale the machine appears on the display. I used all sorts of kettle scalers.

What can go wrong in the brewing unit? 

My machine had delivered 10,500 cups over five years and was now leaking half a cup of coffee into the grounds dump bin. This implied a worn seal (O-ring) somewhere. The simplest cause of a leak would be a worn O-ring on the chamber water inlet nozzle at the bottom of the brewing unit. Look into the lower parts of the machine and you'll see a water pipe coming in from the side; behind it a nozzle points upwards. This nozzle can be seen and almost reached when the mechanism is at the top of its travel. Other causes of a leak could be the two large O-rings inside the brewing unit and this requires a lot of dismantling. With experience you might be able to replace the inlet O-ring in situ (but you might need to dismantle the thing to get the experience in the first place).

Could you service the brewing unit?

You could dismantle the brewing unit; dish wash all the parts and replace and grease the O-rings. It's a big job and is described below. Alternately, if you can remove the unit, you could buy a new brewing unit for £70. The coffee delivery nozzle at the top of the brewing may be different so you can just swap the old top end cap for the one on the new unit. At the same time I changed the lower water pipe and encoder (which senses where the unit is in its travel).

Malfunction 8 

One reason to service the brewing unit comes from a Malfunction 8 message. The message occurs when the brewing unit fails to achieve the correct state, perhaps when you switch it on. The encoder (an optical rotation sensor) monitors the position of the brewing unit. Malfunction 8 may be accompanied by straining noises. A reason is that the motor might be straining is stiffness in the brewing unit mechanism. This can be due to a damaged O-ring or a plug of coffee. 
This Malfunction 8 error can go away on its own. You can clean the parts you can see without removing and dismantling the brewing unit. You may be able to reach into the machine to dislodge some grounds. To do this unplug the machine when the brewing mechanism is at the top of its travel and reach in from below. A dentists mirror would be handy here. Do not indiscriminately squirt cleaning liquids inside as this can get into the wrong places. Do toothbrush; dry and vacuum though. 
The encoding unit could also be at fault. This isn't too expensive.

Dismantling a Jura

I'd recommend you read the following with the additional help of Partsguru who have Youtube tutorials https://www.youtube.com/user/PartsGuruUSA

Before you start dismantling remind yourself of the risks. In case of a mess up, below I've listed a firm selling many spares apart from the actual chassis. They'll sell you a complete brewing unit; a pack of O-rings and grease; encoder; water inlet; water pipes. They also sell replacement water tanks; pump; solenoid; valve; grinding wheels; grinder unit; heater. I haven't tried any of the UK servicing firms so they could be really helpful and cheap. Otherwise it takes a few hours to service and replace the brewing unit. However it took a few weeks to understand that I needed a brewing unit. 
You will need a few Torx; hexagonal and possibly unique screwdriver bits to remove all screws. A pry tool (used for mobile phones) will help where plastic lugs hold on the side and top panel. Empty beans; water store and remove the waste tray. On the Jura F90 use pliers to undo two oval headed screws at the back at the top. If you mash them up you can replace them. You'll be able to remove the top panel after removing two black screws on the top surface and using a pry tool to disconnect two lugs at the front edge.
You don't want to dismantle the coffee grinder and its hopper. Retain the hopper's rubber seals or glue them in place before you lose them. Four screws hold the central back body panel and side panels. The side panels are removed by using a pry tool to release lugs all down the edge where these panels meet the front. Work slowly to manoeuvre the side panels towards the back.  If you simply want to clean the brewing unit externally then just remove the panel on the water side.
Find the water inlet just where the water tank sits. A screw here allows you to remove its plastic holder - but take a photo of how it slots in. This gives access to the lower end of the brewing unit. If the plastic piece is still it the way, you can ease off the water pipe from the water inlet and put it aside. As I said you might get away with not disassembling the brewing unit.

The brewing unit exposed 

The machine is partly operable with the sides and water tank removed. Cover exposed electrical connections and remind yourself of the danger. Thus you can switch off the power when the brewing unit's white gear is at the top and then at the bottom. In this way you will get access to places causing any jam. You might just need to clear the inner chamber and path for two plungers with two large O-rings. You can see the water inlet nozzle with its o-ring which can perish and cause coffee or water to go to waste. Silicone grease only where the O-rings slide. Leave the other plastic parts ungreased. You can however buy a maintenance kit or a new brewing unit from the shop below.
You will want to avoid removing the nylon water pipes unless they're actually leaking. These pipes are held in place with a wire clip (remove with a flat head screwdriver). Ease the nylon pipe with its brass collar out of its socket. The pipe goes into an O-ring in the pipe's socket - this might fall out. These O-rings are likely causes of leaks.

Removing a brewing unit 

... is like removing a car engine. There is no need to force anything. On the Jura F90 the brewing unit is removed by undoing two obscure screws from the coffee grinder side. I had difficulty removing these and I wish I had taken time to find the right tool instead of wearing down the screw head.
On the electronic side there's an optosensor (encoder) unit held in place with a steel clip. You might remove this to access one of the two screws. I replaced my encoder but I think this was unnecessary. At the bottom of the brewing unit, the water inlet valve is fixed to the machine with a single screw. Next, on the water tank side, you'll see two lines of screws that hold the assembly in place. The middle screws of the screws allow you to separate the unit from the gears. The top two holes don't have screws.

Cleaning is all
It is not rocket science to clean the machine yourself. Before hovering check for loose parts or screws! Wipe and toothbrush whatever you can see. Don't wet excessively, but a cloth damped with descaling liquids can work wonders. Do wipe the acid off any metal parts when clean.

Jura spare parts help
When I wrote this, coffee machine spare part supplies were not as common in the UK as they are in mainland Europe. You can buy spares from the UK jura people - I took a photo of what I needed and everything went extremely well hereon. While their web doesn't list every screw you might need, send them a mail and hopefully you'll be as impressed as I was:  https://juraproducts.uk/spare-parts
You can compare prices with a German web shop for machine spares at
 www.kaffeemaschinendoctor.de Their postage policy at £15 a time is ridiculous, at least for small items. The upside is that there are pictorial guides to dismantle the Jura as a pdf. Google will translate it. Another site Juradoctor.de also carry lots of spares but don't seem to ship to my country.

More help:  

In the USA Partsguru have a shop with excellent help on Youtube https://www.youtube.com/user/PartsGuruUSA

A helpful pictorial guide
A link on an FAQ at www.kaffeemaschinendoctor.de has a well illustrated pdf (Anleitung_Jura_E.pdf)


coffeemakers said...

you are linking to the video of coffeemakers.de (see logo on youtube vid) so why don't you link to http://www.coffeemakers.de

Ro G said...

Thank you for the suggestion - so I have added the link to http://www.coffeemakers.de.

However the web menu is a maze and I could not easily find what i wanted.

E- said...

I appreciate this post is quite old, but you're the only one referring to the optical sensor on the unit and wonder if you can help...
My F50 (now nearly 10 years old) doesn't seem to be able to bring the brewing unit to the 'home' position - it locks the nylon cog in the top position and keeps pushing, causing all sorts of horrid noises as the gears slip.
Is there a way to test the encoder (e.g. with a multimeter)? It's not an expensive part to replace, but shipping costs double the price...

KD said...

Hi, thanks for sharing so much info on your site. I have a jura F90, it's about 9 years old and is saying fill system, water portion. When I do it just does nothing? What do I need to do to fix please? Your advice is greatly appreciated. Thanks ��

Ro G said...

Problems with the water works - I've updated the post

To E:
It's guesswork for me to say whether your seals are stuck or the encoder is duff. See edit of my post showing where to buy your parts in the UK.

Jeremy and Diana said...

I realize this is an older post, but I'm having an issue with my Jura Capresso Ena 3. It is about 10 years old and we love it.

Recently the coffee has gotten very weak...like undrinkably weak. I opened up the machine and cleaned the brew group, but to no avail. The pucks seem either to be partially dry or loose and wet. What should I be looking for? What could be causing this? Any advice you give will be greatly appreciated!

Ro G said...

To Jeremy and Diana https://www.blogger.com/profile/11860572690388253109

Let's think about
"the coffee has gotten very weak...like undrinkably weak"

I can see the mystery in this problem. Let's presume the temperature of the coffee is good. Also that the mechanism pushing the 'puck' sounds like its working ok.

You can watch to see if enough coffee grounds are used (maybe clean up grinder)
You can check to see if there's leakage from brewing chamber seals (the waste tray fills up)
You can remove a side panel to see that all pipe connections are sound (open and replace O rings).
If you need spare parts in the UK, go to Jura UK as they are helpful and most of all charge reasonable postage.