# Sage DB, preinfusion not always starting the pump?



## burmanm (Dec 14, 2017)

So I guess something is going out, but I can't figure out what. So, around half the time the preinfusion stage does not start the pump and instead basically only flushes what's in the grouphead. But everything works fine the moment the timer reaches the full pressure. This can be repeated by pushing the manual button also, the moment I stop pushing the button the pump starts and everything is fine. I can hear something when the pump should be running with smaller pressure, but I can't really tell what that sound is (it's very quiet). Could be anything from coil whine.

So why isn't the pump functioning correctly with


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## ajohn (Sep 23, 2017)

You could try going into the semi hidden menu and using the first option to reset to defaults.

I don't understand what you mean by only flushes the group head. The flow wont be very high when the pump is at infusion pressure. All it's doing actually is running at lower speed. It's vibrating piston pump so no starting capacitor etc. The pump might be worn out.

John

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## burmanm (Dec 14, 2017)

ajohn said:


> I don't understand what you mean by only flushes the group head. The flow wont be very high when the pump is at infusion pressure. All it's doing actually is running at lower speed. It's vibrating piston pump so no starting capacitor etc. The pump might be worn out.


There's some water left in the pipes/grouphead I guess and that basically is then let out. But that's it, no more water is pushed (no matter how long it runs). There's a small humming sound coming now that I listened to it more carefully today, so it's doing something, just not pushing water on those occasions. So only works with full power. Although, if it were completely worn out, why is it still keeping the proper pressure (~10 bar)?

But yea, might be time to search for a new pump (must be the fastest water pump to wear out though).


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## ajohn (Sep 23, 2017)

If you do need to replace the pump this may help, old model but probably not changed that much as far as where the bits are.

https://spark.adobe.com/video/sOItplRWjXpvZ








Obviously knowledgiable as he knows that smoke is what makes electronics boxes work as they don't any more once it gets out.

In case mine ever did the same thing I had a nose about on the web. Found 2 reports of the same problem. Breville suggested upping the infusion pressure to 75% but both machines went back for repair. Some sort of firmware upgrade is mentioned as being a culprit as well. Problem really is that unless some one who diy'd it away is found it's not possible to find out what causes it.

It seems pumps can be repaired following wear - dismantle and replace an O ring.

Could be some sort of blockage. Maybe several back flushes and a good descale might help. The "so you think sage descaler is expensive" thread gives and illustration of how effective one particular make is. It's more aimed at thermoblock machines but these have pumps etc as well so may not do any harm - hard to say. 2 ordinary descales on the trot might be an alternative. Also some descalers are more efficient than others - Sage's contain sulphamic acid. That has put me off using pulycaf descaler and several others don't contain it either. I'm a bit cheesed off with what Sage charge for theirs now. Circa 3 quid + a packet with stuff in them that costs pence.

John

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