New user here, came across this forum trying to figure out an issue with my Lelit Elizabeth and it seems there is a lot of technical knowledge here.
I have a Lelit Elizabeth and I decided to try pre-infusion. I adjusted it to 3 seconds in the hidden service menu, and 10s in the quick access LCC menu and when I run a shot the pressure gauge hardly moves at all. Something wrong with it? The pump kicks in for 3 sec as it should, but then nothing happens on the gauge (it barely gets to .5 bar) for the next 7 seconds. Machine is second hand, so no warranty.
I know the gauge works as it shows pressure when I do a regular shot. I know the steam boiler works too since I can steam milk. I tried pushing the boiler temp at 140°C and it made no difference.
Also, the EVS setting is set to 1, and the boiler is on in the LCC menu.
So I opened it. I watched several videos from Lelit insider and understood that the solenoid valve close to the group head has two functions:
- it opens when the steam boiler needs fresh water.
- it opens during steam pre-infusion.
So essentially, water can travel both ways through the hoses. The solenoid must work as the machine refills the boiler when needed. I ran tests with the top off and I can see water travelling to the boiler. During preinfusion, I couldn’t quite see water travelling the other way round, but it’s more about pressure being applied to the water than water actually travelling.
I measured the voltage at the solenoid during pre-infusion and it’s behaving as in the videos mentioned above. I have 230volts at the solenoid during the whole pre-infusion phase. So I can rule out an electrical/electronic bug.
So who are the potential culprits?
- a faulty/clogged solenoid valve? which doesn’t open enough? Water could refill because the pump pressure can sustain 10+ bars, but the 2-2.5 bars from the steam boiler can’t pass the blockage?
- faulty steam boiler? It works flawlessly at the steam wand, but it’s not using the same port to provide pre-infusion. My knowledge of coffee boilers is too lean to know if there are one way valves inside them or something that could cause the issue.
Happy to hear your thoughts. Who could be another culprit? The 3-way solenoid valve? It works during coffee extraction though.