Bezzera Ellisse – Power Up after a Rebuild

Here are my notes about powering up the Bezzera Ellisse for the first time.  The previous owner had said it was shooting steam everywhere, so I was prepared for faults.  What follows is just how I did it.  It is not a recommendation for you to follow.  Coffee machines can be very dangerous if not handled with care.

There are two probe connections on the top of the boiler.  The left hand one (viewed from the front) is the shortest, and is used to sense when to stop the pump.   The right hand one is longer, and when the water level reaches it, it will allow the heating element to turn on (the contactor will pull-in with a clunk).

First, I wanted to check these two circuits worked.

By applying an earth to the shorter probe, the pump would stop.

Lifting the right hand connection would inhibit the heater.

With this arrangement, I switched the power switch to position I.  The pump would not operate until the earth was removed, which is correct.

The element contactor would not pull in until an earth was applied to the right hand heater sense wire.

With both of these probe connections appearing to operate correctly, I replaced the connection to their normal positions, and placed the fill hose in a bowl of clean water.

Switching the power switch to position I results in the pump running and the inlet solenoid opening, both taking place after about 5 seconds.  Because the pump is not self priming, I used a 100mL syringe to fill the hose, and this was drawn into the pump body.  Then the coffee machine filled itself (takes about 10 minutes using this method).  I left the steam taps open in case of any overfilling.

When the contactor came in for the heater, I moved the water level sense probe over to the heater level probe.  In this way, I could check the pump stopped correctly, because I knew the water level was touching the longer probe.  I then restored the connection back to normal.  Note: the heating contactor comes in with the switch in position I, but the heater will not power until the switch is in position II.

When the boiler was full, and the fill pump and solenoid switched off, I fixed a thermometer to the side of the boiler and switched the main power switch to position II.

I opened both the steam taps, so no pressure would build up in the boiler and continued heating until the water was boiling.

When steam began to issue from the steam taps, I closed them and confirmed on a test gauge I had fitted to the top of the boiler, that the pressure was building up.  This had been fitted in place of the heater pressure switch, and was only being used to briefly confirm that the main pressure gauge was working properly.

Despite the gauge test gauge showing 0.5bar, the main gauge showed zero boiler pressure.   So, the first job is to let everything cool down, drain the boiler, and replace this gauge.

With everything cooled, and with the pipework disconnected from the gauge, no water came out.  I expected some flow, and after investigation loosening various joints, a blockage in the connection to the boiler was suspected.  To attempt to clear it, I filled a syringe with 100mL of neat descaler and connected it to the pressure gauge pipe connection.

With some effort, and carefully holding both the hose junctions in place, I managed to inject some descaler.  Then suddenly it all flowed in.  Listening near the boiler, I could hear some fizzing, so I left the descaler in place for 10 minutes or so.  The boiler will require draining and flushing before use.

By the way, the elbow facing downwards is a drain tap.  This has a blanking cap in place to prevent a massive steam outflow if this is inadvertently opened whilst the boiler is full of water over 100degC.

The pressure gauge now agrees with my test gauge (water entry has cause some temporary condensation which should clear over a day or so).

The machine was disconnected and allowed to cool before everything was put back to normal (probe wiring, pressure switch, etc) ready for further testing.

Here is a quick summary of the correct operation of the machine when you switch on:

1. Move the power switch from position 0 to position I.  The red neon by the switch lights.  If the water level is touching the lowest probe, the contactor is energised (but the heating element is not powered yet).  If the water level is not touching the upper probe, the inlet solenoid opens and the water pump operates (takes about 5 seconds to start).

Note, that if the boiler is empty, it may not fill in one go.  To prevent flooding if the level sensors fail (due to scale or circuit fault) the fill pump only operates for a limited time.  To make sure the boiler is filled, when the pump stops, switch the power switch to position 0 and then back to I, until the pump no longer operates.

The water level sensor operating the filling process has a time delay of approximately 3 seconds, to prevent the pump cycling on and of excessively.

2. Move the power switch from position I to position II.   Providing the water level is touching the lowest probe, and therefore the contactor is energised, then the main switch supplies power to the heater via the pressure switch and overheat thermostat.  The water heats until a pressure of 1bar is reached and the pressure switch opens.  This will be indicated on the front panel gauge.

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2 Responses to Bezzera Ellisse – Power Up after a Rebuild

  1. Sebasrian says:

    Do you have photo Bezzera Ellisse on pomp side ?
    It’s possible to send me on email ? I have machine in cartoon box. And I have one problem with pipe connection on pomp side. I wont to be sure.

    Thx you so much Sebastian from Poland

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