Bought this coffee machine in July 2016. It's been descaled a couple of times, but as we live in a relatively soft water area, I don't pay that much attention.
There are a bunch of these machines which look pretty similar in a price range of €25 (Gifi) to €70. This one has a control board and 12V relay which turns off the heater after ~10 mins.
It had started producing little coffee. I descaled it and it was fine for a day, then a problem again. Having striped it, it seems scale had caught up in the narrow pipes in the control valve.
To strip it, you need to remove the control knob. This wont come off as it has a release lever you can't get to.
Remove the base. Triangle heads. Disconnect the blue and white wires to the heater. Remove the 4 screws way up inside.
Remove 2 screws under filler, and gently ease out the silicon seal.
Remove the 2 screws adjacent to the coffee holder
Wiggle the top bit, noting you cant remove it as the knob is in place. Remove 2 screws, 1 each side now visible below control knob.
The top piece and boiler are now free. Turn control knob until release lever (white) is visible inside black knob shaft. Press release and pull knob. I took some material off this so it holds ok, but can be removed with a good tug.
The boiler can be separated. Control part comes off revealing ceramic plates.
Took 3 hours with sulfamic acid (Casino descaler) to dissolve the scale. The boiler is aluminium and there was no noticeable change in the surface finish.
29/6/20 descaled. Filled with liquid twice and ran throigh. Left about 30 mins each time. Knob went very stiff, but ok once cooled.
31/7/20 stopped working. 21R safety resistor open circuit. Replaced with 22R 1/2W + 160mA fuse. Circuit part traced. Cap dropper + FWB, 5V + 12V rails. Looks like a pic - sanded top.
Generic mixer bought from Homebase in 2009.
Not massively different to the other mixer on this blog. In the pic below, the hot inlet to the block is on the right (left when mounted)
The cartridge as shown has cold on the RH mesh.
Taken apart as the temperature control seized up due to limescale and little use. There was plenty of grease in the LH threaded part which was moved around to lubricate as needed. Scale removed gently with a screwdriver and finished with emery cloth.
To get the temperature knob in the right place, set knurl to full hot and place grey part such that the 38C limit pin on knob sits just in front of the max temp grey part. When the knob is then rotated it will correctly stop at 38C. Then need to readjust the knurl, so that full cold forces the thermostatic piston to full cold. Partly remove the knob so that it freely turns and turn in the cold direction until you feel the resistance of hitting the piston. Make this point 20C. Then refit knob and turn towards full hot. When it stops, you'll find that by partly removing the knob, that full hot is ~1/8 turn.
If the last part, readjusting the knurl, is not carried out, the piston has nothing to push against, so will only do full hot.
Notes.
In fully cold, the piston is forced ~0.5mm before it hits the stop.
The piston is 5.5mm at ~16C, and extends to 7mm at ~45C
The control knob piston is 22mm at full cold, and extends to 26.5mm at full hot. moves ~2.5mm per 1/2 turn
Thermostatic capsule marked 5701 8H258
