I have saeco incanto deluxe coffee machine,ventilate msg appears

Check the end of the steam nozzle, make sure it is not blocked. If not then with the knob open for hot water cycle push in on the knob if that works then the tap rod assemble or the steam valve needs to be replaced.

I have saeco incanto deluxe coffee machine, the ventilate message appears. i have tried to load the circuit, hot water message is displayed but no hot water/steam flows out of nozzle, then it tells me to close knob and then ventilate msg appears again

I had the same problem, ventilate message would come on when turned the machine on, no matter how many times I turned the knob to hot water & steam through nothing would happen except could hear the pump running - was about to throw it away, then figured had nothing to lose and looked inside the machine for a blockage.
I looked all over the net and could not find an answer or youtube vid to show how to fix - closest one was something in german on a similar machine!
its not a very easy task, there are loads of little bits packed tight in there. my hands were too big for some places so I had my daughter help hold couple tiny bits to help
essentially I took each main part out and ran some water through it with a syringe until i found the blockage, which turned out to be gunk in a hose next to heater unit.
did it like this:
you'll need some small phillips and torx screwdrivers, allen keys small spanners - 8mm 10mm and 11mm and some needle nose pliers. (if you are prepared you could replace some o-ring seals while you are in there!)
i got my phone to take lots of photos as I went to remember what cable attaches to what
1. power unplug at wall
2. took back cover off and disconnected the magnetic water level sensor and the water intake line.
3. take black plastic drip piece out from bottom right with two screws
4. undo phillips screw bottom of bean hopper and remove, undo torx screws holidng roof on, undo torx screws on the screen/button surround. gently lift roof off, remove the earth wire with pliers and pull the heater power connection to free the roof.
4. unscrewed heater unit (the thing in the hard foam casing) from the boiler, undid the little clip on the end of the hose going to the steam valve and pull out - take care not to lose the o-ring. other end connects to the boiler
5 on the front side removed the drip tray and brew unit, then using an allen key undo three allen screws that hold the boiler in place.
6 back in the back side, GENTLY wriggled the boiler free, and taking care to get LOADS of photos of what wire went where, using pliers pulled wire connectors.
7 once boiler is free, removed the plastic vent part that was sticking out the front into the brew unit and the hoses disconnect from that. the heater is now free and checked to see if water would go through it.
- on my machine this is where the blockage was, so using spanners undid the hose connections from the end - once the nut is loosened off, you can see the little brass ring fixed to the plastic hose, use flat edges of pliers to wiggle the hoses out.
my blockage was in the end of the hose, so I stripped a piece of electric cable, and gently fed it down the hose from both ends and broke up the gunk until it was free, then flushed the tube.
8 repeated the rinse and remove hoses process once the boiler unit was free, so at this point has ensured that flow was good through each component.
(the ventilate command comes up cos no water is flowing, little bits of coffee etc can get in the system and block it at various points)
9. little round flow meter at the bottom of unit twists free, and checked & cleaned this for gunk also
10. put the machine back together in the reverse order, carefully ensuring that every wire and every hose was properly connected to the same places - be careful to take lots of photos as you go if you are doing the same.
11. switched on and voila everything worked as before!
12. ran through full rinse cycle
13. make some coffee!!
seems like ventilate error is something these machines are prone to - something will be blocked. in my case the machine wasn't very old and was in good nick - about 2000 coffees and regularly descaled. if you did this and didn't find obvious block in a hose then could be a different part is blocked or broken and you'd need to source a replacement part?
so satisfying to have fixed it!!
good luck!!!

You may want to give this a try:

http://www.fixya.com/support/t2675737-ventilate_shows_nothing_works

Oh, it was my first coffee machine. I started drinking coffee every day because of it. Now I have a Keurig coffee maker, and coffee pots are way better for me than instant coffee. If you're interested, you can click here to visit the website that I use all the time to buy the best coffee, and I'm sure that you won't be disappointed.