EM6910 Lights flashing wont go READY suspect steam boiler
Hi all, I have an em6910 I got 8 years ago, it's like the toyota hilux of coffee machines, it just never stops, although some things have stopped working over the years. But it does 2-3 coffees a day EVERY day for those 8 years.
Just last couple days, I have had a problem with it where the lights flash showing its heating up but they never go all green to show its in a ready state.
Read some posts on the forums here and did some diagnosis. The steam boiler is not heating up, its cold to the touch after being on for ages.
Ive read about thermostats and thermistors, thermofuses, NTC and I'm a bit confused, on where to start.
I am handy and have a multimeter. Correct me if I am wrong, I have checked the thermistor for the steam block (thats the little thermal resistor at the top of the thermoblock with the 2 little white wires that go back to the PCB, that tells it when its hot enough) Its measuring 80k resisitance when off and cold. The thermoblock itself for steam is cold to the touch when on for ages. The main boiler gets hot cause the group head is real hot.
I also measured the resistance for the "thermal fuse"? on the steam thermoblock and its 0ohm resistance, so I am assuming that means its working. (I also have an old em6900 which works for the most part, and its steam thermoblock gets hot. I checked its "thermal fuse" and its measuring the same so cant be the thermal fuse.)
Anyone know where to from here?
Measure the resistance of the steam element. Compare to the 6900.
At your own risk if the element is ok...
How about swap (on the main board) the wires for the brew and steam thermoblocks. Careful as this will defeat your thermisters and the elements will not turn off. So only power on for 30 sec or so.
If the steam has warmed and the brew hasnt after swapping the wires, then you have a board issue.
If the brew still heats and the steam still doesnt, you need to look more closely at the steam wiring.
^If this makes no sense and sounds stupid to you- then dont do it.
The steam wiring is pretty simple. The element has power supplied 100% of the time from the power lead ( power switch may interrupt...cant recall).
Power runs through the element into the thermal fuse (actually probably the opposite way round) then goes to the board. So the board switches the return....
Confirm what im telling you by looking at the wiring yourself.
Only mess around in there with the power off.
Compare the steam thermister with the 6900 or the brew thermister when cold.
Always plug into a rcd protected power supply. And test it
Thanks will give it a go when I get a chance.
Originally Posted by Jackster