# Fracino Cherub pump problem?



## gwapenut (Nov 5, 2011)

My Fracino Cherub has started behaving strnagely when backflushing or encountering too much resistance while brewing.

I've attached a short video, but basically you can hear the loud pump noise at the start, and then when it meets too much resistance the loud noise stops completely and is just replaced by a barely audible quiet him. At this exact point when the noise changes, perhaps 5mm of water discharges into the tank through the OPV tube - just for a split second.

When it happens during brewing, ie there is resistance but unlike backflushing it's not completely blocked, then the noise might fluctuate between normal loud pump noise and quiet "not pumping" noise. The voltage remains steady at 240V however loud or quiet the machine is.

Am I right in thinking the pump is on its way out?

View attachment VID_20210412_161331.mp4


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## DavecUK (Aug 6, 2013)

> When it happens during brewing, ie there is resistance but unlike backflushing it's not completely blocked, then the noise might fluctuate between normal loud pump noise and quiet "not pumping" noise.
> 
> Am I right in thinking the pump is on its way out?


 @gwapenut It depends on a few things:



how old is the machine...?


you're in a very hard water area, what do you use in your machine?


Those two things dictate whether the pump is old and knackered, or whether you need to do a good descale. Looking at the vent tube there seems to be scale on it unless that's a trick of the light artifact


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## gwapenut (Nov 5, 2011)

The machine is about 8 years old, but I replaced the pump (with an Ulka EX5 from ebay) 2 years ago and the braided hose 1 year ago. If I replace the pump again, I'll probably get it from Fracino this time.

I only ever use Ashbeck water in my machine, but here's the thing - the very first time it happpened was yesterday when I tried to backflush as part of the annual descaling.

I've had 2 coffees out of it today, and it did cross my mind whether a piece of scale had lodged somewhere, but the behaviour doesn't seem to be as fully blocked as when that happened on my Gaggia classic many years ago.


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## gwapenut (Nov 5, 2011)

If it was scale, where do you think it might have built up or dislodge to, to give this kind of behaviour? The OPV and pump are both on the fresh water side of the machine, aren't they?


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## DavecUK (Aug 6, 2013)

gwapenut said:


> If it was scale, where do you think it might have built up or dislodge to, to give this kind of behaviour? The OPV and pump are both on the fresh water side of the machine, aren't they?


 Yes, but you can still get scale...the number of times I've read threads where someones in Norfolk, uses tapwater and never descaled in 3 years...but they don't mention that when they ask what's wrong.

For your machine, I don't know it should be OK, possibly you got a bad pump, something in the water tank got sucked up and blocked it..dunno.


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## ajohn (Sep 23, 2017)

The pumps can stall. I've being doing it on purpose. With a puck in pressure reaches a point and the pumps stops. As it's a puck and the output is dripping rather slowly the pressure ion the puck drops. This may cause it to to pulse again. I've reduced the pump power during in infusion.

So if a pump wears out this could happen. Not sure how your machine is piped but it might be worth opening up your solenoids and checking for sludge in them. There are general instructions about cleaning espresso machine solenoids on the web. Many can be done in exactly the same way. Also check the back flush exhaust path.

Just another point that may only apply to my machine - it looks like a thorough backflush is a good idea before descaling.


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## gwapenut (Nov 5, 2011)

Thanks for the tip on backflushing before descaling, that makes sense but had never occurred to me!

Interesting about the pumps being able to stall, googling with that as a search term has yielded a lot more help.


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## gwapenut (Nov 5, 2011)

As I suspected, a new pump has solved the issue.


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## DavecUK (Aug 6, 2013)

@gwapenut that pump didn't last long, was it new or used from eBay?


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