Newbie alert: my CT1 arrived a few days ago, and it's very much the first lever machine I've ever used. I've taken plenty notes from this thread and the initial review / summary threads, watched my fair share of videos.. still a bit stuck. Is there a trick that I am missing to get the valve to open reliably?

When the machine is heating up lifting the lever doesn't do anything so I suspect there's a thermostat involved that does not allow water to flow from the group until a certain temperature is reached. At temperature (>80C) raising the lever without a basket in place releases water so it's easy to warm up a cup. However, with the filled basket in place I can't get the process to work reliable. Raise the lever, wait for a few seconds, pull down -- and no resistance / no water. Repeat, nothing. Third round works as expected. Rinse, repeat, same problem. It seems to be working more reliably when I raise the lever quickly but with n=10 that could be pure coincidence.

What, uhm, am I missing?

The valve should always open when you pull up the lever and the machine is warm. When it's cold the rubber can be harder and it won't open as easy.

That's very strange. Regardless of whether my machine is on or off, hot or cold if I lift the lever it will open the piston valve and let water pass through. When you lift the lever you should notice two stages. Stage 1 is lifting it until you meet a slight resistance. This is opening the valve. Stage 2 is lifting past he resistance. This is raising the piston up. If you aren't noticing that stage 1 then it seems like you should take the piston out and see if you can determine why it's stuck.

I had an email exchange with Wouter and just received this as part of my email from him today, may be helpful:

"You can have a look if the center valve opens directly when you start raising the lever..
Check by removing the filter holder, now very gently lift the lever just a bit, the center valve should open and water should start to flow down directly. if it doesn't the piston moves up with it preventing it from opening. To prevent this you can lift the lever a bit more quickly, give it a little upward knock at the start(to open the valve), then raise up slowly all the way.

Ones the machine is used for 1/2 months the rubbers will wear in a bit and the center valve will open more smoothly."

Is Wouter's design meant to eliminate (as much as possible) creating a vacuum on the lever raise. so as not too introduce air, which might disturb the puck?

The piston has a central hole that allows water to pass through the piston. A plug attached to the lever arm seals this opening against a soft oring seal. The first action in lifting the lever arm raises this plug without moving the piston itself. Without the portafilter in place water will flow through this opening and into the drip tray, so it's hard to imagine any air being pulled into the chamber with the portafilter in place.

IMAWriter wrote:Is Wouter's design meant to eliminate (as much as possible) creating a vacuum on the lever raise. so as not too introduce air, which might disturb the puck?

I believe that's correct. I don't think it completely eliminates all possibility of air in the group, especially if you lift the lever too quickly, but cracked pucks and the like are a non-issue. I think the piston design and the point you're bringing up plays a big role in why I find it to be such a forgiving machine.

one1speed wrote:I had an email exchange with Wouter and just received this as part of my email from him today, may be helpful:

"You can have a look if the center valve opens directly when you start raising the lever..
Check by removing the filter holder, now very gently lift the lever just a bit, the center valve should open and water should start to flow down directly. if it doesn't the piston moves up with it preventing it from opening. To prevent this you can lift the lever a bit more quickly, give it a little upward knock at the start(to open the valve), then raise up slowly all the way.

Ones the machine is used for 1/2 months the rubbers will wear in a bit and the center valve will open more smoothly."

I've received a similar email from Wouter minutes after I posted the original question. A slight tap during the initial lift seems to be working just fine -- I should have made the connection between the temperature and the valve based on earlier comments.

Anyone has tried different pre infusion times/pressures yet? I have a Colombian SO here right now where i had great results with 25sec pre infusion followed by around 30sec pull for 40g.

For ethiopians i so far stuck with the recommended 8seconds.
Have not tried annything else yet

A minor bump in the road with my CT-1, now resolved, but I thought I'd share the solution here for reference:

A couple of days ago, the machine stopped heating. White light would come on, red light never came on, group never got warm. I figured it was the over temperature protection switch, and emailed Wouter for assistance. Within 24 hours, I got his reply, with pictures, to solve the problem. It did indeed solve the problem, and here is his reply:

"To reset the overheat protector: (I have included 2 photo's)
First unplug!
You open the back of the brew group (the electric box). Remove the 2 screws (one above and one under the box)

At the back of the box behind the bottom off the group you see a round white switch with a black knob in the middle.. You press it in to reset. (you should here a click)

Now the machine should work again."

I had been experimenting with higher temps, had actually cranked the knob up to high, but had NOT changed the temp control knob with the set screw. I'll go back and check the water temps with a thermometer, at different temp adjustment dial locations. I'm normally just leaving it on for a few minutes in the morning, and I did have it on longer for a few days, so I may need to dial down the temp if I'm going to leave it on longer than usual.

Mainly, I just wanted you guys to have a reference for the easy solution if this happened to you.