Is Anna dead? Ibertial L'Anna pressure issue

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Is Anna dead? Ibertial L'Anna pressure issue

Postby CakeBoy » Thu Feb 23, 2017 2:27 pm

I fear Anna is dead. What we know is she has an HX pressure fault. She has been totally stripped and rebuilt. In essence, she can sustain any pump pressure but, rather like a wind sock, will not build or retain excess pressure.

I think this has been occurring slowly over a prolonged period and we have been compensating, but, just after a descale in December, she started making a strange siphoning type schooshing noise from within until reaching HX pressure of 9 bar and was then just her usual self noise wise, but the coffee was changing a few seconds into the shot from viscose sweet syrup to watery yellow lemon juice, and oddly combining in the cup like marble cake opposites. The temperature drops during shots too as would be expected with a pressure loss.

It is clear that she cannot retain 9 bar intra shot in a restricted (coffee laden) basket, but she can retain 9 bar behind a blind basket or head manometer.

Everything has been changed, so pump, motor, solenoids, head, pipes, silicone tubes, flowmeter (!! :oops: ) non return valve and OPV can be ruled out. She has a pressure leak, quite likely from the HX unit itself, though a smoke test of the boiler was inconclusive, but not surprising as no pressure is involved and any hole would be very small in reality.

We know it's a pressure leak as, on reflection, she has not flashed her manual pour (right hand end) light for over pressure for as long as we can remember. I suspect the issue is longstanding but has just reached a point where the noise has appeared and flavour is directly impacted.

We changed the fluid-o-tech OPV and she immediately flashed over pressure with the closed circuit manometer in the head. Pleasingly, the needle flew to 9 bar, then after a couple of seconds crept up to the 12 bar setting of the OPV, which then bypassed the excess pressure perfectly. That happened once. I believe the addition of the brand new OPV assisted with the pressure issue but in going so simply increased the hole and left us back at square one.

The OPV was changed for a heavier grade CMA Astoria type and the same thing happened again, she worked once then seemingly the additional retained pressure increased the hole size. The pattern repeated with a really heavy grade Izzo OPV but this time she flashed over pressure but would not retain excess pressure. I suspect the hole is just too big now, wherever it might be. To be certain, the OPV was removed entirely to provide a truly closed circuit and she still would not retain the excess pressure.

It has to be a hole leaking pressure because she can sustain any throughput of any pressure right up to the pump maximum 12 bar, but she cannot retain excess and is clearly letting it out somewhere.

With hindsight, we had been getting a few surprisingly odd tasting coffees these past few months and I think she has been harder work, like driving a car in high winds, a bit of wrestling to keep control. It may even be quite longstanding and slow developing. Compensating by users may have masked the problem for a while. Either way, a new boiler just in case is not really cost effective.

Please may I ask any L'Anna owners, are you still able to achieve an over pressure light warning on your L'Anna and if so, does your pressure build up and then the OPV open, thus holding the pressure at the bypass setting, typically 12 bar?

Thanks so much, my apologies for the long winded explanation :)
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