Hello, The last few times I've put the machine into cleaning mode I've noticed, after once I've inserted the cleaning tablet, the first phase , the pump pushes enough water through to the nozzle, but then when it goes to the short bursts for 8mins or isn't enough pressure to push it through the piston and it just comes through into the drip tray from the spring valve at the side of the distribution unit and it doesn't clean it properly as a result.
I completely overhauled the machine today, replaced the piston seals and decaled the mesh on the upper and lower pistons and they look absolutely fine, including the little rubber pressure Gromit on the top piston.
I then got to the distribution gears and disembled this, the ceramic plates look perfect and there's no scale.
I removed the little drain spring valve at the side of the distribution valve and again this was clean and the valve moves freely.
Put it back together and it still does the same. The machine is about 5 years old, so ideally I don't really want to replace everything to diagnose the problem. I'm guessing it's either that spring valve (not sure if you can buy this on its own) or whether the piston isn't allowing the water through freely enough (which I don't think is the issue).
It makes coffee absolutely fine when the pump runs long enough to push it through the brew piston, although there is more water than I would expect in the drip tray after.