Sunbeam EM6910 Repair pointers...

[Xanthine]

Yes, a couple of scoops of the powder in the double unpressurised filter with the disk in the bottom then run the backflush cycle - hold down single and double buttons and power up (from memory).
The machine automatically runs 5 or 6 backflushes and the last one is a long flush with the three-way open so it pushes a good amount of water through it.
It's also a good idea to soak the group handle, baskets & shower screens in a hot solution of the powder as this gets them really clean.

Anyway, let's hope you get lots more good coffees out of it now!

[Footleg]

Glad to hear you got it going.

I see you mentioned descaling the brew path but this is only effective for scale buildup in the thermoblock - it is better to use a 'detergent' tablet or powder to remove the coffee oils and fine grounds which clog the backflush pipework. Occasional fresh water backflushes between the chemical backflushes also help to keep things working.
I have found the Cafetto Espresso Clean powder to be very effective and more economical than the Sunbeam tablets.

Thanks, yeah, I do have some of that sort of stuff - "Premium Espresso Machine Cleaner" from "Clean Machine" apparently... You put a small amount in the blank then backwash. Guess I just need to use it and the descalers more! Although the water down here in Vic is pretty soft anyhow and there are no obvious signs of scale building up.

Using a Sunbeam descaling liquid, I followed the process of heating the machine up, power off (at mains!), disconnect steam heat connector, run the steam (on the kitchen hob under the extractor on max!) until the residual clears and it's pushing water, powered off for 20 mins, run clear... Might look at a vinegar based option also...

[LeroyC]

Glad to hear you got it going.

I see you mentioned descaling the brew path but this is only effective for scale buildup in the thermoblock - it is better to use a 'detergent' tablet or powder to remove the coffee oils and fine grounds which clog the backflush pipework. Occasional fresh water backflushes between the chemical backflushes also help to keep things working.
I have found the Cafetto Espresso Clean powder to be very effective and more economical than the Sunbeam tablets.

What he said. [emoji1303]

[Xanthine]

Glad to hear you got it going.

I see you mentioned descaling the brew path but this is only effective for scale buildup in the thermoblock - it is better to use a 'detergent' tablet or powder to remove the coffee oils and fine grounds which clog the backflush pipework. Occasional fresh water backflushes between the chemical backflushes also help to keep things working.
I have found the Cafetto Espresso Clean powder to be very effective and more economical than the Sunbeam tablets.

[rawill]

Great work Csers, another 6910, back up and running again.

[Footleg]

...ok - had some success. After removing some of the pipe work, it was clear that the short pipe, picture, was pretty seriously blocked.

To answer some of the other questions, no, there was nothing coming back down the drip tray after a brew or when back-washing with a blank.

So, it seems reasonable that if the solenoid is working, then the "blockage" is in the pipe BEFORE the t-junction. And yes, the pipe was blocked. Cleared it out and put it in some descaler, blew through it a little until it seemed to be running free.

Now, we seem to be back in business - the pressure gauge climbs, it "sneezes" back in to the tray and the puck is drier! Although the sneeze is not as strong as it used to be... Pump or more build up?

** SUCCESS **

Time for a major descale! Whilst I have the covers off, seems like a good time - will read up on the tips for descaling the steam and thermoblock.

Thanks again to this site and the folks on it for making DIY possible!

(PS - I hate putting the damn lid back on - the four screws that hold it are a pain - mine really seems to be a poor fit!)

[LeroyC]

So, covers are off... Looking at the solenoid value, per picture, one pin is the source 240v, the other, when not brewing, is also showing 240v. When a brew cycle starts, it dives to 0v (ish) and the solenoid clicks. So, on the surface of it, it looks functional, although no telling at this stage whether the valve is indeed moving.

Where is the rubber valve on the output @Chris? Per markup in picture?

Are you getting water into the drip tray after a shot or backflush? This would indicate the solenoid is working. If it’s flowing in there while the pump is running then it’s stuck open.

[Xanthine]

One terminal is connected directly to Active and the other terminal is switched to Neutral via a FET in the control board so the readings you got are probably correct.

If the 3way is leaking you should see a trickle of water into the back of the drip tray during the whole brew time and not just a 'sneeze' at the end when it releases the pressure in the group.

The brew pump over-pressure valve is in the "T" you have arrowed in your photo. From memory it is spring loaded and can be adjusted once the clear plastic tube has been removed, but should ideally be adjusted using a pressure gauge (not the one in the machine as this is likely to be very inaccurate)

There is an earlier post with photos of the pumps somewhere on the forum but it would take a bit of searching to find (sorry, not sure where).

Also, the pumps have an internal diode in series with the solenoid coil so can appear o/c when checked with and ohm-meter - best done on 'diode' setting.

[Footleg]

So, covers are off... Looking at the solenoid value, per picture, one pin is the source 240v, the other, when not brewing, is also showing 240v. When a brew cycle starts, it dives to 0v (ish) and the solenoid clicks. So, on the surface of it, it looks functional, although no telling at this stage whether the valve is indeed moving.

Where is the rubber valve on the output @Chris? Per markup in picture?

[Footleg]

Thanks very much - I think I'll try and open it up today and have a good look around...

[Chris]

Also symptoms of when the rubber valve on the output side of the pump is playing up - sticking or deformed.

[LeroyC]

Quite possibly the 3-way solenoid is stuffed. The pressure gauge line tees off right at the 3-way so it can sometimes indicate this is the issue. Unfortunately they’re a pretty low quality 3-way apparently. Do some testing to see if this is the case. Check to see if the 3-way valve is stuck open, blocked or stuck closed. Check the coil (ideally with a coil tester, but you’re just checking for continuity. With the machine unplugged of course). Some more learned members might have more insight so hopefully they chime in.

[Footleg]

Hi All, what an awesome thread...

Sadly, my EM6910 is in need of help again. With help from this site, I've done work inside before - declogging pipes when it wouldn't back flush properly, replacing the collar etc. But I fear more serious surgery is now required...

Essentially, whilst it's still producing shots, the pressure gauge isn't rising and the puck is much wetter than it used to be. Changing the grind doesn't make too much difference to either the gauge and the wet puck (nor does increasing the dosage), although it does affect the pour as it should.

Initially, I just assumed the pressure gauge itself was dud, or the pipes to it were blocked. But now I'm not so sure. Reading through most of the thread I'm wondering if it's the pump itself (common issue?) or the solenoid, or something else. Seems both of those parts are quite expensive given the age of the machine - but I'm not sure I can bring my wife round to a new one (although reports of a 7000 at $400 might make it over the line!!!).

Any guidance on further debugging would be appreciated.

Thanks in advance,

Anthony..

[Moph]

Crickey, can you taste the coffee

60mL double shot per glass using a 22g dose in a 20g VST basket ... the 225mL milk per glass stretches out to around 275mL, so that's a espresso:milk ratio of around 1:4.6 ... plenty strong enough for a larger morning brew. Total volume is around 330mL which is just a normal tall drinking glass.

For our evening lattes I use 250mL Bodum glasses so that's 60mL espresso to 180mL milk for a ratio of 1:3. I wouldn't want to go any stronger than that.

[Logga]

Crickey, can you taste the coffee