Vibiemme Domobar Internal Photos non-Heatexchanger Version

This is a quick look at the internals of the Vibiemme Domobar espresso machine, the one with the single boiler which you heat up to about 90deC to make your espresso, and then switch it to steam and allow it to further heat up to 145decC for you to foam your milk.

I explain this, because there is also a version with a larger boiler and a heat-exchanger which allows the simultaneous brewing of coffee and steaming of milk.  I have some internal photos of this machine also and will post them shortly.

Okay, covers off.

Beneath the top cover is the water tank.  This sits on a sprung platform, and unless there is sufficient water in the tank it will not press down sufficiently on the micro-switch below the sprung platform.  The prevents the element from heating up and causes much frustration.

Here is the sprung platform removed and upturned to show the screw which presses on the micro-switch lever arm.

The micro-switch sits under the water tank and sprung platform.  Unfortunately, the lever arm can become bent, and this can make the machine think that the water tank is prematurely empty.

Here is a first view of the boiler, to help you get your bearings.

The group head is heated by thermo-syphonic action and has two copper tubes forming a circuit via the boiler.  With the boiler up to temperature, the heated water will flow through the group head without the need for any pump, and so keep the group at the perfect temperature for brewing.  The two pipes to the group connect to the boiler approximately half way down on either side.

The steam valve is fed from the centre tapping at the top of boiler, and is connected to the separate steam arm.  Within the boiler is a thermostat pocket, which accepts the vial from the capillary thermostat situated at the top right.  This sets the coffee brewing temperature and has an adjustment accessible from above..

There is also a bimetallic steam thermostat screwed to the top of the boiler, which opens at about 145degC.

The Vibiemme uses an Ulka EP5 water pump, which is able to provide up to 15 bar of pressure.  This is reduced with an Over Pressure Valve (OPV) to around 11bar, which bleeds water back to the water tank to reduce the system pressure.  It is recommended to reduce the brewing pressure to approximately 9 to 10 bar, but to do this it may be necessary to disassemble the OPV and cut a turn off the spring.

We hold stock of spare parts for the Vibiemme Domobar, including the element (1800W), brew capillary thermostat, shower screen, group gasket, Ulka EP5 pump, power switches, descaler cartridges, and bottomless portafilter.

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18 Responses to Vibiemme Domobar Internal Photos non-Heatexchanger Version

  1. Rosemary Passey says:

    I have enjoyed my much loved and cherished Vibiemme Domobar for the last 15 years. Unfortunately the silver (innox) weave hose has begun to leak. (30cm long 3/8 inch internal diameter of nut) I have tried in vain to find someone to repair or supply parts in rural France and have ordered a new hose which does not fit. Please could you advise me if you could supply a hose, or if not, if you could suggest where I might find one. My mornings are no longer the pleasure they used to be and my family is suffering.
    Thank you for your advice.
    Rosemary Passey

    • admin says:

      The hose should be fairly easy to obtain, especially in France where 3/8″ fittings are common and flexible braided hoses are used for connections to sink and basin taps.

      Personally, I would try a local DIY store with a plumbing section, or if then end sections of the hose are okay, I would cut out the bit in bad condition and use a pair of joints to fit in a new section of hose.

      Obviously you would need to be confident of the repair, as there are bare electrics present.

      Worth considering, if you can obtain some hose of the same diameter, is getting a hydraulic firm to refit your existing fittings onto the new section of hose. This may be more likely in rural France.

      The pump operating pressure is approx 15bar.

      On balance, with some searching, it should be possible to locate a suitable hose quite easily I would have thought.

      Perhaps you could use this type of hose, with flat washers:

      And two 1/2″ to 3/8″ brass reducers in the end:


  2. Peter says:

    I have a problem with my Vibiemme Domobar (single boiler , without heat exchanger): the thermostat located on the boiler needs to be replaced.
    It is written on it ELTH 261 T175K .
    Is it the one you are talking about as 145degC ?
    I was just wondering if at this temp the boiler wouldn’t blow up..

    Thank you very much,

  3. Emanuel says:

    thanks for the post, very interesting.
    I have the same machine of the pictures.
    Unfortunately, something happened and for some reasons the machine drop the pressure.
    I dismantled the pump and try opening the over pressure valve, but when I put it on again the pressure is still at 5 bar. Actually I don’t know if the problem is Ulka pump (which seems fine) or the pressure valve…Any suggestion?

    • admin says:


      The pump should be capable of 12 to 15bar. The overpressure valve opens at about 10 to 11bar and bleeds the excess pressure back to the tank.

      You will not be able to get good pressure from your rebuilt pump unless you have bled all the air out of the system.

      With a cold machine, switch on, the operate the coffee switch. Open the steam wand and let water run out of it until it flow smoothly without air bubbles.


  4. Gijs says:

    Hi Steve,

    Many thanks for the info – I am living in Cape Town and probably one of the few with this old Vibiemme Domobar who is central in our morning rituals!

    The heating element to my knowledge blew – multimeter measures couple hundred kOhms or prety much burnt? I assume it should be about 25O hms?

    So my question where can i get the parts. Also is it safe to insulate the boiler a bit to make it more “economical”



  5. Simon Dewar says:

    I have a problem with my ~ 10 year old Vibiemme Domobar (single boiler , without heat exchanger). It has become very noisy and suspect there is a problem with either the pump or the OPV. Do you know where I can get a replacement OPV in the UK. I’ve tried removing the spring and replacing which worked for a while but wonder if the piston is sticking ?

    Any help much appreciated

    • admin says:

      Hello Simon,

      I have not seen the type of OPV fitted tot he Vibiemme available, so you will need to adapt one.

      If you check ebay item 161429732010, this will do the job, but you will need to adapt it to fit with some 1/8 brass or stainless steel fittings.

      I will send you a PM about this.


  6. Oli says:

    Hi Steve ,
    i live in New Zealand and on my Domobar single boiler is the boiler corroded. Any idea where i can get a new one in this world? I had no luck in NZ so far .
    Thank you very much

  7. oli reuschel says:

    Hi Steve,
    the boiler has arrived, thank you very much.
    I just found out that the 2 cooper tubes to the group head are missing.
    Can i order those of you? and could you send them in an envelope that they fit in a letterbox ?

    Thank you very much

  8. Tan says:

    Hi Steve, may I know if VBM piccolo brew pressure can be adjusted? I think my current pressure of 11.5 bar is very high. Do you know any link on this forum that can guide me to adjust the pressure. Is it called the OPV, which is connected to the pump shown in your photo with a silicon tube connected to it with a big flatscrew head on top?

  9. Tan says:

    Oh sorry, I just saw your instruct “It is recommended to reduce the brewing pressure to approximately 9 to 10 bar, but to do this it may be necessary to disassemble the OPV and cut a turn off the spring”.

    Do you mean I have to remove the whole OPV and separate it from the pump? What do you mean by “cut a turn off the spring”?


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