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VBM Domobar Super pump issues...

RiderRider
edited January 1970 in Espresso Machines
Morning Cremas,

In September we needed our pressurestat replaced as it had started leaking.

The tech replaced the original with a Sirai one, not the same as before but all was okay.

Over the past week or so the machine had developed an odd problem.

When extracting, the pump starts, goes through preinfusion, then takes off but when it gets to 8 bar it basically  backs off to near idle and the pressure then begins to drop. Needless to say the extraction is slowed and average.

Shut it off and pull the lever again and the pump is at super low level. Leave it for a while and then it will kick on as per normal but again go through the same routine outlined above.

This morning went to purge the grouphead and was at least 45 seconds to 60 seconds before any water came out........

Anyone got a lead on where the problem lies?

Faulty pressurestat?

Blockage?

Cheers

Rider
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Comments

  • LacehimLacehim
    It's not your pressurestat because it regulates boiler pressure (ie how hot your water gets).  Sounds to me like a blockage or scale build up, faulty pump or OPV issues. Did you get it serviced fully while the pressurestat was being replaced? If your not into pulling it apart to find the issue, I would get it back to your service tech for a full look over. :)  The more you try to troubleshoot it by using it, the more damage you could be doing. Let us know how you go. :)
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  • RiderRider
    Cheers Rang the tech people yesterday, they said they would talk to a tech and get back to me. So far I have heard approximately nothing  :( One of their techs lives nearby. Suggested he drop in and I can show him.......... See what happens...... Oh yeah and when I scaced it last night, water temp is 85........  nice one......
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  • RiderRider
    By the way I don't think it is a blockage, as when the group handle is not on, the pump operates normally and water flows freely. It only wigs out as it hits 8 bar......
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  • RiderRider
    Well 3 coffees this morning and it worked perfectly. Forgot to mention I did caffetto the crap out of it Thursday..... Maybe something finally dislodged? After cellar door today it will get another huge caffetto-ing this evening.....
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  • Brett HBrett H
    Great that it is working properly this morning.  I would be inclined to run it as normal now rather than poke it with the caffetto stick.  I've had issues when I've been over zealous with cleaning agents.  Just a thought but so glad you're up and running!
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  • RiderRider
    Thanks Brett And now it gets interesting... Yesterday, machine on @ 5.20 am. 1st coffee, 6.05 am - worked fine. 2nd coffee, 9.15 am - pump backs away at 8 bar. Today, machine on @ 7.00 am. 3 coffees within an hour starting @ 8.10 am - worked fine. Machine left on, Coffee at 3.30 pm - pump backs away at 8 bar. Machine turned off and allowed to cool somewhat, Turned on @ 5.30 pm. Scace test @ 6.15 pm - pump worked fine. The pattern would obviously suggest overheating of internal parts yes? Cheers for any help Rider who still can't understand why the pressurestat they put in it produces <85 C
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  • LacehimLacehim
    on 1384759597:
    who still can't understand why the pressurestat they put in it produces <85 C
    The pressurestat is adjustable. ;)  If you don't like it, turn it up (just make sure the machine is off before you do it!) Seriously, would you drive a car around that kept stalling or cutting out when you got to 80kph?  No.  Get it to someone that can fix it and get it running smooth especially seeing as Christmas is coming! ;)
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  • RiderRider
    Well aware that you can adjust it. Had previously adjusted the original to provide correct temperature and pressure as I own a Scace 2 device. The new pressurestat is not OEM so when you take the top off and the loose mushroom out of the heat cover, the adjustment screw is not visible....... As I mentioned, thanks heaps for that Mr Coffee Tech..... now I have to dismantle part of my machine to make a simple adjustment. That in itself has been found out during the process of trying to understand why the pump keeps oscillating. I will get to the pressurestat in time. My main concern is the pump and the intermittent oscillating and trying to corner the reasons why. From the information I have provided I would hope you can understand that I am a bit tentative in dropping the machine back to them and was only hoping for a small end of tunnel light from the brains trust of the forum. Rider
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  • RiderRider
    Further to my inquisitiveness on timings, I have left the machine on and will do another Scace test around 10.00 pm to see if the run time (machine on) is the issue. Can report back if anyone feels like they can add or help. Thanks in advance Rider ....who endures crap internet and had the above reply sorted hours ago.......
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  • Brett HBrett H
    It sounds like it might also be the pump: http://ulkapumprepair.blogspot.com.au/2008/10/original-website-page.html It is possible also that your service guys have done you a disservice.... Can you Thame it to a different repairer for a second opinion?
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  • Brett HBrett H
    Or... Could it be a power issue: rectifying diode on the pump unit.  I remember reading about that on the Interweb! 
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  • RiderRider
    Hey Brett, Delayed use this evening and the pump worked fine.... Go figure.... Murphy's Law. Still showing low temp, which does concern me as boiler pressure is where it should be but temp is low compared to OEM pressurestat. Thanks heaps for the article, but with the price of pumps ($60 odd bucks) I think I'll plug and play. As mentioned above I am kind of averse to going back to the tech, other than to get a pressurestat that suits the machine, at his cost if I can make that happen. They are going to get an interesting email from me....... Thanks again for the reply and the link, you have been very helpful. Cheers Rider
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  • RiderRider
    Oh sorry mate, And on your question of a different repairer...... No, we moved from Sydney to the Hunter Valley around 4 months ago. Lots (and I mean lots) of bonuses....... This is one of the downsides..... :(
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  • Brett HBrett H
    Well then...  The Hunter eh  :thumb: There should be some great Syrah and aged Semillon to take the edge off!! Keep us posted!
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  • Koffee_KosmoKoffee_Kosmo
    I am a former Novacasrtian  and the greater hunter region resident Family still live there  KK
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  • RiderRider
    Haha, thanks you two... Well the Coffee Tech actually rang me back today (well the receptionist did) and after 6 days the result was - "I have spoken to a couple of people and they have said you need to bring the machine in for a bench test"..... 6 fruiting days for that?????? I think if I need to get anything done I will drive to Sydney and back twice and still be able to chop a few days off the overall. The pressurestat took over 2 weeks so no, never again. Moving on, it has been fine recently. In the dark recesses of my mind I think this has mostly (always) happened at low reservoir levels. I have been wondering if the has been too much tube in the reservoir therefore pushing the opening higher........ We have been keeping an eye on that and all is fine so far. Yesterday I took the reservoir out and rinsed it and the start up noise was strikingly similar to that of my problem - i.e. water starvation...... So on a lighter note, yes Brett, there is a good Syrah or three up our way. Of late there seems to be a push toward younger Semillon. A lot of vineyards not doing a malalactic fermentation and therefore leaving the green apple/cirtus young vibrancy to the wine. Personally I think this is good thing as the Semillons went a bit extreme for a while, just like the oak in the chardonnay. At cellar door it nearly seems trendy to not like chardonnay - humorous...... You can still find or create a great aged Semillon as that is what Semillon does. Vibrant when young, suffers a personality disorder in the middle years and then comes out a bit like us.... Aged, mature and well rounded.... :laugh: If you are in the area there is accommodation for you two gentlemen, just let us know. Cheers Rider
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  • Brett HBrett H
    What a kind offer mate! Many thanks!  I reckon ditch the current mob and contact Neil Atwood to see if he knows any good Techs or Jet Black are in Cremorne.  It's 6 hours return but if you plead your case they may book it in to look at it on the spot for you.  Obviously give them plenty of lead time.  All the best mate!
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  • RiderRider
    Final installment..... I hope  :) A week later and all is fine. It would appear that when they worked on the machine originally (pressurestat) they shoved the two tubes so far into the reservoir that they did a U-turn at the base and had the ends sticking half way up the reservoir, therefore causing water starvation to the pump before the low water switch kicked in. Positioning the tubes correctly at the base of the reservoir and we have not had a problem since... Definitely a different technician with future problems. Rider
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  • hiphiphararhiphipharar
    on 1385421979:
    Definitely a different technician with future problems.
    Glad you got it sorted. Sounds like you are becoming that future technician. On the other hand, I hope there are no further problems.
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  • LacehimLacehim
    Glad you got it sorted too.  Keep asking around in the mean time and you might find another place that services machine, should you ever need it.  I find asking local cafes can be quite useful. :)
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