# Problems with my Gaggia Classic pump



## djallen70 (Nov 14, 2015)

Hi guys, I'm new to the forum!

I bought a second-hand Gaggia Classic a few weeks ago, which was working fine for the first couple of weeks. About a week ago water would stop coming through the grouphead, which seemed to be triggered by trying to backflush the system (which I had done successfully once before) or when putting additional pressure on the system (e.g. When making a ristretto). In both cases, the pump noise would go very quiet and water would stop coming out of the group head except in very small occasional drops. Water/steam was coming out of the steam wand as normal.

After reading up around grouphead problems, I took the showerhead and holding plate off and cleaned them and descaled the machine (previous owners said they'd done this every 6 months, so was expecting some build up). On a couple of occasions I got the water flowing normally out of the grouphead again, and managed to pull a shot using coffee ground far coarser than usual. However, as soon as I tried my usual grind (for a regular double espresso) same happened - pump went quiet and water stopped flowing through the grouphead.

I next took the solenoid out to give it a proper citric acid soak and clean, and it appeared to be in good nick, with water flowing freely through it. In addition, I can clearly hear the "click" when I turn the coffee switch on, suggesting the solenoid is working fine. It had left me with dry pucks when the machine was working, so I'm assuming there's no problem there. I done anything to the OPV as yet. Now the solenoid is back in, there is hardly anything flowing through the system, not even through the steam wand.

I also took the outflow tube from the pump off and pushed water through it, which flowed out of the steam wand with little resistance. Does this rule out a blockage down the line? Lastly, I ran the pump without the outflow tube attached, and got the same quiet hum and just a dribble out of it. Video link:






My question is, is the problem clearly with the pump, and does it just need replacing? Or could the problem be elsewhere? I'm a complete newbie, so any advice would much appreciated. Cheers.


----------



## timmyjj21 (May 10, 2015)

Sounds like you have a done good diagnostics. Usually poor flow out the head is due to the solenoid, also indicated by water coming out the steam wand fine, but now it looks like you have a jammed valve In the pump, probably due to the descale dislodging a bit somewhere. I'd assume you have a red Ukla pump and there are a few guides on stripping them.

http://ulkapumprepair.blogspot.co.uk/2008/10/original-website-page.html?m=1

It's probably a jammed internal valve. The quite sound is due to water pressure reducing the vibration.


----------



## Jumbo Ratty (Jan 12, 2015)

Id still say its the solenoid. Backflushing seemed to trigger it. Suggesting to me it is the problem.

When you backflushed it was you using only water or the correct backflushing powder like urnex cafiza?


----------



## timmyjj21 (May 10, 2015)

Jumbo Ratty said:


> Id still say its the solenoid. Backflushing seemed to trigger it. Suggesting to me it is the problem.
> 
> When you backflushed it was you using only water or the correct backflushing powder like urnex cafiza?


Not according to the video. The pump isn't moving any water. Agree that it was originally solenoid, but this is different now


----------



## djallen70 (Nov 14, 2015)

Thank you for you replies, I really appreciate the input.

So I stopped and cleaned the pump according to the link timmyjj21 sent and it's worked like a charm. The pump is working vigorously again and water is coming out happily through the grouphead. The solenoid is working as water is coming down into the drip tray after I've pulled a shot, however I haven't tried backflushing yet and have been using a coarser grind than usual to avoid triggering the problem again with too much pressure.

I'm awaiting the delivery of a Mazzer mini, which I'm hoping to dial in with no issues from my Gaggia. Thanks for your help so far, hopefully I won't need to appeal to you again!


----------



## djallen70 (Nov 14, 2015)

Jumbo Ratty said:


> Id still say its the solenoid. Backflushing seemed to trigger it. Suggesting to me it is the problem.
> 
> When you backflushed it was you using only water or the correct backflushing powder like urnex cafiza?


Thanks for your thoughts on this. Pump is working, although I'm not ruling out solenoid issues. It seems to be working okay for now, although haven't put the system under much extra pressure. When I back flushed before I used cafiza, and it worked fine.


----------



## John Albert (Oct 4, 2020)

I have a similar problem but my pump seems to be a sealed unit so I have ordered a new one, my questions is can I get descaler into the old pump to try to save it and keep as a spare? Gaggia Classic 2003.

Bye for now John


----------



## HDAV (Dec 28, 2012)

John Albert said:


> I have a similar problem but my pump seems to be a sealed unit so I have ordered a new one, my questions is can I get descaler into the old pump to try to save it and keep as a spare? Gaggia Classic 2003.
> 
> Bye for now John


 The pump on a 2003 should be serviceable (unless it's been changed before?) put some pictures up of the old pump to aid diagnosis.


----------



## DavecUK (Aug 6, 2013)

I think for the sake of £13.68, it's not really worth it.....

https://www.amazon.co.uk/Ulka-EP5-Water-Pump-German/dp/B003MS6E20/ref=pd_day0_79_3/258-5443373-9577041?_encoding=UTF8&pd_rd_i=B003MS6E20&pd_rd_r=d6ab50bc-0cee-42b7-b7c6-2dcf2af90234&pd_rd_w=8SLEH&pd_rd_wg=KwhZ7&pf_rd_p=82bea144-0110-40ad-957f-5614a5716224&pf_rd_r=0P7SA7PPQA6QWRERR22B&psc=1&refRID=0P7SA7PPQA6QWRERR22B


----------

