Jura coffee machine repairs

by roger · Published May 2021 · Updated Jul 2021

visitors this year: 437

… how to service or replace the brewing unit on a Jura coffee machine and other fixes.

It might be assumed that if you can afford the BMW of coffee machines, you can afford someone who can fix it. You might instead be someone who likes coffee a lot but you’re keen to avoid those costs.
I hope that the following discoveries might save someone the weeks I spent dismantling a Jura coffee machine. It sat in my workshop like a car to be restored. It then gained a new ‘engine’ for £100 – which is less than £1200 for a new machine. If I’d understood it better I might have reduced that to £5 (for new O ring seals).
Since this post was first published on my other site in 2013 it had been referred to 20,000 times – or 2500 times a year or 7 times a day

Basics: which is better value, a bean to cup machine or a pod machine?

Short answer: if you drink 6000 cups of coffee (or 3 cups a day for 5 years) the cost of owning either machine is the same. Thereafter using a bean to cup machine instead of a pod machine will cost £150 less per year. My break-even point of 6000 cups of coffee arises from these costs:

A coffee pod machine, such as a Nespresso or Tassimo machine was bought for £50. The coffee pods cost about £0.25p each. Therefore 6000 cups of coffee have cost me £1550

My bean-to-cup machine, such as a Jura F90 cost £900. The coffee beans cost £10 per kilo and if 11g is used per cup, each coffee costs £0.11. Therefore 6000 cups will cost £1560

Basics: the cost of ownership is not nothing

If the Jura F90 isn’t a machine you throw away you will have some costs due to accidents, neglect or age. I buy spares from https://juraproducts.uk/spare-parts

Machine new £800
Replace brew unit £80 – I might have just replaced the ‘O’ ring seals at £5
Replace cracked water tank £12 – I now use a jug to refill the water tank.
Replace broken metal frother arm and other small parts £15
Replace thermoblock, I and F connectors and membrane regulator £67

My Jura coffee selector touch panel is unresponsive or erratic

After dismantling and reassembling my Jura F90 (below), the machine would spring to life at random and make coffees resulting in a mess on the counter. The touch screen was unresponsive at times. This may have been a problem I caused but now it’s fixed. The touch-screen coffee selector works better when cleaned and left to dry. A German forum post suggested that steam can get behind the touch panel and it recommended that you put plastic film (or card or shirt collar packing film) horizontally beneath the touch panel and so isolate it from the steam from the coffee dispensing area. This has worked well for me since.

Coffee bean grinder problems: the grinder can be serviced easily

You don’t have to take the grinder to pieces to service it. Some youtube 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 section of dismantling below). You’ll see the coffee bean hopper held in place by two vertical screws. Approach them gently with a torx screwdriver bit else you’ll break the screw’s fixing point.

Note the position of the consumer grinding adjuster as you obviously want to replace everything as it was. Hoover excess beans. Lift the hopper clear of the body. 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 do some more cleaning up. If you just want to clean up, don’t loosen the central grinding wheel. Instead see this video, where the Saeco (another brand) has a similar grinder. As I said earlier, don’t over tighten the two torx hopper screws after reassembling.
https://www.youtube.com/watch?v=5M5WmOYzTAU

Plumbing problems: the Jura F90 coffee machine is leaking

My Jura F90 machine leaked and messed up the wood worktop beneath it. Most of this water damage was due to emptying the grounds and regular removal of a full drip tray. But there were other reasons.

There was a leak from the internal plumbing.
There was a leak from the brewing unit (see Malfunction 8 below)

Inside the unit various teflon tubes transport water from place to place so if you suspect the internal plumbing there’s some dismantling to do. A section below explains how to remove the side panel on the coffee grinder side to access the pump and tubes. The tubes are teflon/plastic and held in place by a wire clip. Scale around a connection might suggest a leak. Remove a wire clip and withdraw the tube and its brass collar. Inside the connection there’s a tiny ‘o’ ring seal. You can replace or re-seat this ‘o’ ring. Some ‘o’ rings (in a spares kit) are the same size but e.g. intended for high temperatures. Push the teflon tube and its collar back in firmly and lock it with the wire clip.

After 11 years and 16,000 cups the leaking from my 2004 Jura F90 was getting serious. I contacted UK Jura spares (below) to replace the ‘o’ rings in numerous connections. These are all 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. I also replaced the membrane regulator unit (after the pump at the front bottom of the machine) which I heard is notorious for leaking. The parts I bought had been modified from the originals on the machine but the spares dept helpfully provided what I needed.

Basics: using the Jura Impressa F90 daily

This model sits in the middle of the Jura range. The middle of the Jura range compares to the top of everyone else’s ranges! The F90 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 the grounds need to be emptied. What you experience is not entirely spoofed intelligence and it works well.

The ‘Empty grounds’; ‘Descale’ and Clean machine’ messages derive from counters which guess the needs.
The ‘Tray Missing’ message comes from a microswitch.
The ‘Fill Beans’ message appears if no coffee powder arrives in the brewing unit – the sensor is probably in the grinder.
The ‘Fill water’ message is triggered by a microswitch facing the tank and/or a sensor in the plumbing.

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.

When you see the message ‘Machine Scaled’ you respond by removing the water tank and turning on the machine by holding the Maint. button. What you must do to descale the machine appears on the display. I use all sorts of kettle scalers. 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.

Problem: Jura coffee machine brewing unit 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; the electronic garnishing (display; control programme and buttons) will differ.

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 dentist’s mirror would be handy here. Do not indiscriminately squirt cleaning liquids inside as this can get into the wrong places. Instead use a toothbrush; dry it and then vacuum.
The encoding unit could also be at fault. This isn’t too expensive and is easy enough to replace.

What can go wrong in the Jura 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 Jura 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 and buy a new brewing unit for £70 – £100. The coffee delivery nozzle at the top of the new brewing unit may be different but I could swap the old top end cap on my old unit for the top 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).

Dismantling a Jura coffee machine

I’d recommend you read the following with the additional help of Partsguru who have Youtube tutorials at 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 (but not 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. At the time I haven’t tried any the UK spares dept who today would get my first call.

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 drivers; 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 panels. Empty the 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 with regular screws. 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 a likely causes of leaks.

Removing the brewing unit from a Jura coffee machine

Removing the brewing is lengthy job akin to a removing a car engine. There is no need to force anything. When you’re inside 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 a 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 – do that

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 rinse 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 for small items and typical of buying from overseas. The upside is that the site has pictorial guides to dismantle the Jura as a pdf that 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