EM6910 blocked solenoid valve after descale
I descale fairly frequently with the last time being a week.
I have been realising that my backflushes aren't effective as the solenoid valve seems to be blocked and nothing is coming into the drip tray. I have followed a guide on how to backflush correctly.
Anyone have any thoughts on how to fix this?
I descaled with Sunbeam Descaler.
Thanks very much.
Rather than using de-scaler I think you should be backflushing with cleaning tablets or Cafetto.
Also, are you getting a pressure reading on the gauge as this will give a clue as to where the blockage is.
Another possibility is that the solenoid coil has failed.
A bit more detailed info would help to localise the problem.
Thanks for your reply.
So I am using liquid descaler in the water tank and when I clean the group head, backflushing, I am using cleaning granules (not sure of the brand).
Yes, the pressure can get nearly to the red when backflushing. I can make good coffee, etc, no issues there.
I put the group head through another cleaning cycle today as per the manual with cleaning granules and pressure was fine but not once in the process did any water come out of the valve into the drip tray. I assume that during that process there should be some kind of flushing into the tray through the solenoid valve.
Hope that makes sense!
Well, it sounds like you are doing all the right things there!
OK - just one more question. When you turn the machine on and it is heating up from cold does any water or steam trickle into the back of the tray?
From memory the solenoid valve is open at this time and residual water in the thermoblock(s) expands as it is being heated. A trickle from here would indicate that the solenoid valve is OK. If this is not happening it could be blocked.
When backflushing there is normally a noticeable sneeze of water into the tray as soon as the pump stops. Also, the last flush of the programmed backflush cycles is a continuous flush for a couple of seconds with the solenoid valve open and there is an obvious flow of water into the tray.
Thanks again for your help!
No, no water into the tray through the valve for those two examples.
So it sounds like it is blocked. Would it need to go for a service or do you think I would be able to take it apart and unblock?
Also, how bad is it to be blocked in the way it is? I mean, it still makes good coffee, etc.
Depends on your DIY ability. I took one apart and it had a blockage in a small copper pipe connection, small diameter with two or three 90 degree bends, only 3 or 4 cm long. Once I clears this the pressure releases out to the drop tray as it should. I can't recall where the gauge feed is I relation to this pipe.
The "T" for the pressure gauge is directly adjacent to the solenoid valve so the valve looks to be a good candidate for the blockage.
Tommyp - you could just keep using the machine as it is. Just don't release the group handle immediately after pulling a shot otherwise you might get showered with coffee and grounds.
It's a bit of a fiddly job to remove the valve so I wouldn't like to advise one way or the other. If you keep using it the way it is and still doing regular backflushes you may get lucky and it could clear itself. (Then again, the blockage could become worse and your pressure gauge stops!) So I guess the ultimate decision is up to you and you would need to take into account the age and condition of the machine. Sorry I can't be more help than that. If you were somewhere nearby I would be happy to have a look at it for you.
Artman and Trev,
Thanks for your help.
I had a look at the back of the machine and decided not to go further as I don't want to start undoing stuff and not being able to put it back together. The plan now will be to backflush regularly and hopefully it unblocks itself. Trev, I am in Tamworth so quite far from you I think.
Thanks again and fingers crossed it unblocks itself!
Good move if you aren't that way able. It's not hard to take apart but fiddly. Keep up with the chemical back flushing, if it's just crud blocking it it should budge eventually.