Ease of service is one factor that distinguishes the commercial espresso machine from the home or 'prosumer' espresso machine. Commercial machines are also assembled with heavier parts, sturdier fittings and more modular design. When your business depends on one piece of equipment, that machine has to be reliable. It must also be easily and quickly repaired in the event of a failure.
I have busted knuckles, sliced fingers and scraped the skin off my hands trying to work on some of the 'prosumer' machines. Vibiemme stepped up to the plate on the Domobar Super design. No gyrations are required for a basic teardown and replacement of failing parts. The entire outer casing comes off in under two minutes. The outer shell is held on with 6 large slotted screws, three on either side. You simply unscrew them and lift the shell off the machine.
You have side access to the inner workings once the shell is removed. Inside the machine is an inner housing that separates the water reservoir from the boiler and electronics. That is easily removed by unscrewing two stainless steel Phillips head screws located on top of the inner cover and two small Phillips head screws located at the rear, bottom of the machine. Once removed the inner housing tilts back and lifts off the chassis.
All the internal workings are easily accessible once the cover is removed. Dominating the inside of the machine is the large copper boiler. Across the top of the boiler (moving left to right) is the vacuum breaker and a three-way fitting that supplies the steam wand, boiler pressure gauge and pressurestat. Located in the top center of the boiler is the upper thermosyphon line. To the right of that is the boiler pressure relief valve which is set at 1.8 bar and then the water level sensor probe. Under the boiler is the lower thermosyphon line and heat exchanger inlet.
The boiler is supported by a large U-bracket that is brazed to the front and rear portion of the boiler's underside. That bracket is then screwed to the frame providing ample support. That support relieves tension on the thermosyphon lines, which adds to longevity and reduces the risk of strain-related leaks.
The Parker pressurestat sits high in the frame. This unit does not use a solid state relay (SSR), rather it directly controls the heating element via contacts that close when the pressure in the boiler drops. The Parker pressurestat is rated for 25 amps at 300 volts. The contacts close with an audible click. It is far from being noisy, but noticeable in a quiet room. But if you were looking for a super-quiet espresso machine, you would not be purchasing a vibratory pump driven machine.
Vibiemme has made adjusting the pressurestat very easy. Removing the cup warmer tray from the top of the machine reveals a small black plug atop the inner metal housing. Simply lift the plug off and insert a slotted screwdriver into the adjustment screw. The adjustment on the Parker pressurestat is very wide. Unlike most of the smaller pressurestats, a full revolution of the adjustment makes a small change in the boiler pressure. That makes fine tuning the pressure much easier.
The pressurestat on my machine has a 0.13 bar deadband, which is on par with other pressurestats of this type. Another noteworthy feature is the pressurestat support bracket. While some machines rely on the pressurestat tubing for support, the Vibiemme Domobar Super uses a heavy piece of zinc plated steel. The mount is screwed to the base of the frame and extends up the right side of the machine. The pressurestat is mounted to the steel bar, relieving undue strain on the copper line and fitting. The mounting bracket is clearly visible on the right side of the machine.
The 41 watt ULKA vibratory pump is mounted on the left side of the frame. The pump is completely rubber mounted to dampen vibration.
The OPV (Over Pressure Valve) is located in rear of the machine. For those of you new to the espresso machine world, the OPV controls brew pressure by venting excess pressure from the pump and returning the water back to the water reservoir. The Vibiemme has one of the heaviest OPV's I have seen. Once the outer shell is removed, you can access the adjusting screw through an opening under the water reservoir. The angle is a bit awkward but still usable. It would be easier to access if the opening was cut a half inch lower. To adjust the OPV, turn the screw counterclockwise to lower and clockwise to increase.
In the extreme rear corner of the frame is the Gicar controller box. The controller is attached to a small riser to elevate it above the floor of the machine. That will keep it away from water spills in the frame. The controller is then strapped to the socket to prevent it from coming loose. The location of the box puts it as far away from the heat of the boiler as possible. It also sits near vents in the base of the frame to provide further cooling.
The right side of the machine contains most of the wiring. The heating element inserts through the right side of the boiler. The water tap is on the right side and is mounted above the heating element. That prevents the boiler water level being accidentally lowered below the heating element. The Parker boiler-fill solenoid and its boiler-supply line is also located on the right of the boiler.
Hiding behind the pressurestat mount is the boiler over-temperature breaker. It is easier to access than it looks in the photo. Gone are the days of struggling to find a replacement for a blown thermal fuse. If the Super's breaker trips, you can easily push the red button to reset it.
The three-way power switch is massive by home espresso machine standards. It is protected from overhead spills by a stainless steel shelf. The switch itself is encased with a silicone cover. That should provide more than adequate protection from the occasional drip and spill. I have worked on commercial multi-group machines and recognize its commercial quality.
All of the electrical connections are made with fully-insulated crimp connectors. I gave all the connectors a wiggle to see if anything was loose. All the connectors were firmly locked onto the spade fittings.
The machine is well put together and very sturdy. All the fittings appear to have a hefty wrap of Teflon tape and are firmly secured. There were no signs of leaky fittings inside the machine. The wiring is a little cluttered but routed away from heat sources and secured with nylon ties. Almost every part on the machine can be easily accessed and changed within minutes.