Ever since I bought my Rocket Giotto I have been annoyed with the need and amount of flushing involved.
My pressurestat are set at 0.9-1,1 bar, which gave me an idle temperature of 98-100 degrees Celsius. I flushed about 1,5 oz before every shot. Not only did I use a lot of water, I also spend a lot of time doing it.
So I bought a thermosyphon restrictor.
A small piece of brass, designed to reduce the water flow to the group head, and lower the temperature. Very simple, inexpensive and relatively simple to install.
After installing it, my machine idles at 88-90 degrees Celsius - and I now flush UP in temperature. Just like a dual boiler. My flush time is 2 seconds. I think the upgrade has been awarding in a very big way.
First of take of the top.
Remove the tank, sides and rear.
It's a lot easier when the work space is as big as possible.
Locate the pipe, coming from the boiler to the brev head and take it of.
The restrictor is suppose to fit inside the 90 degree bend on the boiler.
Make sure the inside of the bend is clean, if there's a bit of scale on the walls, the restrictor won't fit.
Even though my walls were clean, the restrictor didn't fit. I had to grind it a bit. You should be able to push it inside, but still have a tight fit, so that it doesn't tilt inside.
Install the restrictor with the small end in the bend.
Remount the pipe, lube the ends a bit with food grade lubrication, and be gentle with the tightening.
Turn on your machine and activate the water, do a couple is bachflushes to make sure it doesn't leak anywhere.
When you are certain everything is sealed properly, let the machine heat for 30 minutes.
When it's heated install your pressurestat at 0,9 when it's at the lowest. That way you should end up with a "cold nose" !
With the low pressurestat setting, my steam power went down a little. To compensate for that, I removed the silicone hose inside the steamwand. Basically the silicone hose make sure the metal doesn't heat when steaming, providing you with a no burn steam wand. But at the same time it makes a lot of resistance in the steam.
The easy way is to take of the steam tip, and just pull hard in the hose.
The better way is to take it all apart and lube everything at the same time.
Disassemble the wand from the machine, be careful with the spring.
Take of the ball joint and remove the hose.
Assemble everything in the same order, but lube the Ball joint and spring with food grade lubrication.
Now your wand will rotate flawlessly and still deliver a lot of steam.
But remember its hot now !
As mentioned this is a profitable modification to any HX machine that idles at high temperature. So get going and do the mod.
Enjoy
