# Sage DTP fault



## Gary5709 (Oct 25, 2016)

I've had my DTP for a good 2 1/2 years now and its been a great machine. Its now having a problem. Every time I make a coffee on removing the portafilter there is an explosion of coffee everywhere like there is a huge pressure build up that causes this as it feels like theres a pop when undoing it releasing the pressure and causing the coffee to explode everywhere. The switch also feels very stiff now either to brew or steam and my coffee is not extracting properly when I brew giving awful tasting coffee.

Any ideas what could be causing this as I'm not really sure apart from maybe the seal in the group head but on looking it all seems fine.

Thanks in advance


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## adam85 (Feb 16, 2018)

I've only had mine a short while - so there will probably be someone with wiser words - but I have noticed this incident on mine also.

However, the only time it ever caused a problem, was when I was filling the Portafilter way more than I should have - above the Sage trimmer tool, etc.

Once I had figured this out, and not ground the beans too fine, it never seemed to happen again...

I'm sure, given you've had the machine for a while, this may not be the cause of problem - but thought I would mention


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## PPapa (Oct 24, 2015)

Are you hitting your target weight and time, still?

If you are choking the machine with too much or too fine coffee, that's reasonable that there will be pressure build up.

I am suspecting OPV valve might be acting up, but I cannot see how that affects the taste.


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## MWJB (Feb 28, 2012)

PPapa said:


> Are you hitting your target weight and time, still?
> 
> If you are choking the machine with too much or too fine coffee, that's reasonable that there will be pressure build up.
> 
> I am suspecting OPV valve might be acting up, but I cannot see how that affects the taste.


There's no OPV. The brew switch is on/off, so if it can be started & stopped at target weight, it's not affecting coffee taste as @PPapa says.

Sounds like too much coffee/too fine a grind. @Gary5709 get some 0.1 g or 0.01g jewellery scales and keep to the same weight in the basket (10g for the single, 18g for the double).


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## M_H_S (Jun 6, 2018)

Try different coffees and different dosages and report back.

Eg. I get that at times with darker roasts.

Also try leaving the pf in for longer so the water is drained by the solanoid.

This is the most likely reason that you are taking the pf off immediately after likely overdosing or and grinding too fine.


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## jonnycooper29 (Apr 11, 2018)

I occasionally get this, but if I change the grind/dose, I'll be changing the flavour for the sake of fixing the problem. I don't see the point in dialling in to the flavour I want, then changing it due to some splutter when taking the pf off!

However, i found that if you leave the pf in place, drink your coffee, then go take it off, it should be absolutely fine! I guess it can take a minute or so for the pressure to dissipate..


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## Gary5709 (Oct 25, 2016)

Thanks for the replies.

I've not changed anything from the way I've always brewed my coffee and having been doing it now for a good few years I know how to change my grind/dose etc to make necessary adjustments. Please don't take that sentence as being snotty towards the comments you've made as thats not what is intended at all just that I've tried all the usual stuff but it still keeps happening. Leaving the portafilter in for a while after does stop it happening but that shouldn't be whats needed as it was never an issue up to now. When it happens the coffee brewed comes out very bubbly, is very bitter and has no crema which is very unlike my usual results. My doses are coming out correct weight in/out wise which is why the whole thing is puzzling


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## PPapa (Oct 24, 2015)

I really think a video of your shot preparation and the pour would help a ton.


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## DAH (Nov 3, 2018)

This is just a guess, and it can't hurt, so I'd suggest a descale if you haven't done one recently. Seems to be a good place to start If other things aren't resolving it....


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## ajohn (Sep 23, 2017)

I believe there is an OPV but no three way valve.







Actually sure there is an opv and suspect it's set at 15bar just like the BE.

Sounds to me that as it's a more recent problem you may need to do some serious back flushing. That though assumes some route through the machine is blocked and more associated with a 3 way valve.

That leaves the puck itself. Probably seriously overfilling. You don't mention the quantity of coffee or the shot time you are using however over filling isn't as simple as it may seem. I used the single on the BE a lot with a certain bean and struggled with obtaining the strength of drink I wanted. Too much coffee actually weakened the drink. The reason for this is that the grounds must have some space to expand, if that is restricted the pressure just builds up. The effect as far as flow with time is concerned is a little like grinding finer except the actual flow rate will initially be higher slowing as the grinds expand. In your case a lot of water is probably going out of the OPV valve into the drip tray.

Grinding finer and finer is more likely to leave a wetter puck but I'd be surprised if the pressure still didn't relieve itself through the puck in seconds rather than the time it takes to drink a drink but I've only used machines that have a 3 way.

It would be easy for you to see if it is overfilling. Just razor your current dose off and see what happens. You'll probably get a lot more coffee out in what ever time you use which can be fixed by grinding finer. Tuning for taste is tedious as there is a large range that might suite. Ratio wise say from 1.5 to over 3 and time from say 20 to 40 secs maybe more. Also the dose which can be adjusted within limits on any basket.

I generally used the BE with slightly overfilled baskets as it allowed me to tweak the dose of grinds via it's grinder timer and keep it constant. Eventually I just started with razored pucks to get the grind more or less correct. Then increased the dose by small amounts, 0.2g on the single until the puck stuck to the shower screen than added another 0.2g which stopped that from happening.







With hindsight as I can't work this way on the DB this way of filling the baskets helped obtain consistency. I've had to use other methods of achieving that on the DB.

John

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## ajohn (Sep 23, 2017)

Gary5709 said:


> Thanks for the replies.
> 
> I've not changed anything from the way I've always brewed my coffee and having been doing it now for a good few years I know how to change my grind/dose etc to make necessary adjustments. Please don't take that sentence as being snotty towards the comments you've made as thats not what is intended at all just that I've tried all the usual stuff but it still keeps happening. Leaving the portafilter in for a while after does stop it happening but that shouldn't be whats needed as it was never an issue up to now. When it happens the coffee brewed comes out very bubbly, is very bitter and has no crema which is very unlike my usual results. My doses are coming out correct weight in/out wise which is why the whole thing is puzzling


Bubbly has cropped up before. Really scratched my head on why this might happen until I had it. Air trapped in the puck. Another cause might be air in the water added some how as it's taken out of the tank. Might be time to take the lid off and see if there is any signs of that when a shot is pulled. Maybe this can happen from the tank to the pump. Hard to see how it could happen after the pump but ...............

If I thought I had a scale problem as a one off I would buy some Durgol and run it through the machine as slowly as I could via hot water or take things apart and do it manually using sulphamic acid. Not a good idea to have that contact aluminium, brass fittings not sure. The tubes in the termcoil are stainless.

John

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John

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## dmreeceuk (Apr 18, 2018)

I got exactly the same when for some reason my grinder changed calibration. I was choking the basket. Bitter bubbly coffee with no crema and splatter when I took the portafilter off. I really think your choking the machine with either too much coffee, too much tamp or too fine a grind. I found that you get to a point where you go finer and get lots of crema but bitter coffee then if you grind finer still, the crema disappears. I think it just stalls the flow.


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## ajohn (Sep 23, 2017)

I had a nose around on spares for the DTP. Just an OPV valve and nothing else. The BE gives people a flow meter and a 3 way valve. There are parts lists about for all of the machines - USA spares suppliers.

Under tamping can also cause grief. Some beans clumps to varying degrees and if the tamping doesn't more than swamp that flow through the puck wont be even. Some people stir the grinds up. I get fluffy grounds so don't as just doing that can make some beans clump worse than how they came out of the grinder.

People do all sorts but I decided to stick with the old 15 - 17kg. Early on I bought a calibrated tamper intending to turn it down to fit Sage's small baskets but never did. When I switched to the DB thought I might as well use it. I'm pretty sold on them now along with a levelling tool.







I'm not keen on spending money and expected to sell or throw away the levelling tool but it compresses and firms up the grinds enough to ensure that tamping is square to the basket.

John

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## Iris (Oct 29, 2018)

Have you tried giving the baskets a really good clean, incase any of the little holes are blocked? would also suggest a good descale and backflush.


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## Gary5709 (Oct 25, 2016)

Thanks for the comments. Still having the problem and have now noticed that the pre infusion time has started to shorten by about 2-3 seconds. Always starts pouring at 12s but now the coffee seems to be starting earlier. Whether this has any significance I don't know but if anyone has any ideas it would be appreciated. A major concern is that the switch has become very stiff now to turn either to brew or steam settings so I'm not sure if there is a fault going on there or its a sign that something is going to go wrong very soon.


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## M_H_S (Jun 6, 2018)

Sorry to hear you're still having trouble with it. Not easy to resolve but some additional observations for you:

1. The stiffness of the dial i have noticed is when the machine is not primed for use. So e.g. if i turn it when the machine is off or heating up it will be stiff. This means the machine itself thinks it is not at the right temp possibly. You could check water output with a thermometer to confirm.

2. If the pf has all this pressure it could be to do with whatever mechanism the DTP uses to drain the excess water. Even though it doesn't do this that well without a solanoid, it still does it somehow. Perhaps you could check this by removing the tray and putting something under the drainage output at the back to see if there is excess water once you stop pulling the shot.

3. The fact that your shots dont taste as good logically means one or more of the parameters is off i.e. temp or pressure.

4. 12 second down to 10 second preinfusion I am not sure about as i had thought DTPs are preprogrommed for 10 sec preinfusion but never really checked.


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## Iris (Oct 29, 2018)

have you tried descaling and backflushing? first real thing to do when you are having problems a good clean/descale. It might fix things.


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## Gary5709 (Oct 25, 2016)

Thanks for more of your feedback.

Machine has had a full descale and still having the same issue. Not sure what everyone else here does but I've always been a steam first, brew second guy. I have tried switching this method and brewing first and the explosive results have then stopped. The problem then that still happens is that when steaming is done the dial becomes very stiff as I described. This makes me think that something is wrong with the temp somehow as the machine is obviously steaming at a higher temp and cools down to brewing temp again.

The pre-infusion issue seems to be getting worse as I'm getting coffee starting to pour at 7-8s which is way sooner than usual. Grind and dose wise I am still staying the same as usual so that variable can't be the issue. Brewing first seems to be giving me a good result taste wise with good crema but still the output is being affected due to the short pre-infusion time as so I am having to grind finer to compensate which I shouldn't have to be doing. Please correct me if I'm wrong on that point but usually with a too coarse grind I still don't see any output till the 10-12s mark just get a much faster flow and therefore an over extraction in the usual time 25-30s ish.

Any feedback would be appreciated again as I still can't seem to figure out whats going on.


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## Oldone25 (Jan 3, 2018)

Hi,

I get a similar effect but to a lesser extent when using my current supply of Monsooned Malabar beans.

I brew and leave the portafilter in place for another 10 seconds and all is fine, I don't know what is different with this particular bean as I haven't seen this with other beans, however, I will be trying another batch from my roaster shortly.


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