Siemens eq 300 TI351509DE no coffee

Hello,

I am at my wit's end.
When I start the machine no water runs through the brewing unit but everything goes directly into the drip tray.

What has been tested so far:
- water goes up to after the heater
- hose from - I call it times - distributor to the brewing unit is new incl coupling
- brewing unit seems to be in order
- motor above seems to be in order

When switching on comes out about only 2 drops where the brewing unit draws its water.

What else could I check as a layman?

Hello,

A couple of weeks ago I bought a Siemens EQ.300 second-hand for a penny and a half, just to have a backup unit here at Camp Krusty (these kids like coffee man!).

The machine was pristine on the outside, only the milk frother tube was missing. But of course, it was not working. When I switched it on the whole LED light festival came in.

Since this was my first encounter with this model (I'm the proud owner and maintainer of several other Siemens machines but all of them are the big brother EQ6 series). Boy, does it make a difference, I know this machine is way cheaper but the brewing unit is at a whole different level compared to the models that have it on the side.

My first issue was to find the correct position to install the brewing unit. To do that I started removing the brewer's drive unit on top (well, of course, first you have to remove the covers but that's pretty easy for this model compared to others I've seen).

The drive unit doubles as the directional valve, and it's actually the part that controls where the water goes, either to the tray or to the heater. When you open the drive unit, the gears will probably pop up but don't worry, the initial position is indicated for the two gears that need to be aligned (note the holes on the bottom and top side of the unit's cover). After you open it, you will see the ball-shaped valves, but I doubt the problem is there (if you start by opening the drive unit as I did, of course, take advantage to take a look and clean the valves but they look very robust). To be honest it took me more than three hours to figure out this dammed part but once you understand it, it all makes quite a lot of sense.

In the meantime, while I was trying to figure out the drive I removed the pump and open it up. It was good as new but for some strange reason the solenoid shells were not in the right position (there are two metal shells and one shorter made of plastic). If in your machine the water is flowing to the drip tray I guess your pump is good. If you have the time you can check it out anyway, you'll find many videos on YT about it. In my experience, some units do tend to fail, but after many coffees served (8-10k is what I've seen but I guess it depends because the critical parts are made of plastic).

Next, I decide to take out and test the PCB but there was nothing to be learned there (other than it is very good quality and it has the mighty ST32F100X microcontroller, an old friend of mine. Be careful if you disconnect cabling, some connectors are a bit stubborn and you might break them (in particular the one going to the control panel on the front). At some point, I even cracked open that panel as well, only to find another mcu to take care of the buttons and funny enough a connector for a small display. After a while of playing with the drive and trying to understand the right position of the brewing unit, I was really tempted to fetch a screen to try to debug what was going on (it is way easier when you have a screen and those glorious service menus that you find in other models). The only solution I found was trial and error brewing coffees with the door open (bypassing the door's contact with my finger). If you do that, do not brew caffe crema if you don't want to have the machine spitting steam all over your face).

The last thing I did was removed and cleaned the heater (yeah, why not? It was the only thing remaining in place). Surprisingly enough, the inside of the heater was clogged with lime so I guess the previous owner never cared to calc and clean it, use a filter, or even use good water. That might be your problem as well if your machine is older than a couple of years or you use it very frequently.

Finally, when the time came to put everything together I realized I forgot to recalibrate the tightness of the grinder, and the first coffee I brewed was carrying huge grains. So I had to open it up again (sigh).

Long story short, my machine works like clockwork now. I still have to receive the frother to be able to prepare my beloved lattes but other than that...

I have to say that even though the quality of the machine is not the same compared to more expensive models, I am very happy with the taste of the coffee. And now that I am familiar with the machine I think the only weak part is actually the brewing unit, the rest is of similar quality or even the same parts. For the repair, you do miss the screen, it's like being blindfolded.

I hope you find out what's wrong with your machine. If you need further details, do ask and I will try to help you.

Regards,

Marcos

Hello again,

I forgot to mention something that might be important. After I was done with my machine I noticed it kept asking to calc'and clean (note this particular machine came from a place with very hard water and I suspect the previous owner never calc'and cleaned it).

So I relented and decided to do the cycle. But I had run out of cleaning tables, so it took a week before I could do it, and all the while I was using my machine twice or more per day and working perfectly fine.

When I finally did the calc'and clean all seemed well but the next morning no coffee came out of the nozzle, all water ended up in the tray together with the (very dry) coffee powder. I tried two more times before I switched to my main machine (an EQ 6).

One thing I noticed when I did the cycle was that the cleaning table went more or less intact to the residue compartment on the tray, which was weird.

I thought the problem might be related to the brewing unit so I took it out and thoroughly cleaned it, but to no avail; still no water coming through the nozzles.

I did not want to take everything apart again, so I decided to take a chance and I did another cycle (but this time with no cleaning table and no descaling solution, just tap water). The cycle seemed to work just fine, with half a litter of water going to the tray in its first stage and another half through the nozzle. After that, the machine started brewing coffee normally and it's been working fine ever since.

So heads up: before getting busy taking everything apart you might want to try calc'and cleaning a couple of times...

Good luck.

Regards,

Marcos