I am having pressure at the group head problems on my (10-11 year old) Techno.
Pressure gauge on machine measures pressure at the exit from the pump head - not at the group head.
Pump is rotary.
Gauge measures 0 bar when water inlet off. 3 bar when water inlet on.
When using either blind filter for backflushing OR basket with coffee in max pressure on gauge is 3-4 bar.
Adjusting pressure valve (on pump) makes no difference to pressure reading on pressure gauge.
Three way valve on solenoid releases after every shot.
Backflush works as normal - can see suds coming back up out of drain in drip tray and hear valve release.
Group head clean. Shower screen clean. Plate removed - all holes clean.
Water debit on a shot normal/as programmed.
Minimal/no crema on coffee.
When pouring a shot it is either (depending on grind): dripping slowly (brown/blonde) or running fast and blonde.
No in between.
Any ideas much appreciated.
Pressure gauge on machine measures pressure at the exit from the pump head - not at the group head.
Pump is rotary.
Gauge measures 0 bar when water inlet off. 3 bar when water inlet on.
When using either blind filter for backflushing OR basket with coffee in max pressure on gauge is 3-4 bar.
Adjusting pressure valve (on pump) makes no difference to pressure reading on pressure gauge.
Three way valve on solenoid releases after every shot.
Backflush works as normal - can see suds coming back up out of drain in drip tray and hear valve release.
Group head clean. Shower screen clean. Plate removed - all holes clean.
Water debit on a shot normal/as programmed.
Minimal/no crema on coffee.
When pouring a shot it is either (depending on grind): dripping slowly (brown/blonde) or running fast and blonde.
No in between.
Any ideas much appreciated.

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