Well, it started with the pump running too long, intermittently. At the same time, the pressure wasn't dumping when the lever was lowered at the end of an extraction.

I've been trawling through the great information on this site, and so far have:
-disassembled and de-scaled the group head (very cruddy). Now re-assembled, seems to work fine....
-removed the water level probe, cleaned, replaced, tested. Needs replacing, but works.
-disassembled and de-scaled the OPV, all freed up (again, very cruddy).
-disassembled and de-scaled the Parker solenoid and its associated connections (Part 22 & 23 here: http://espressocare.com/images/Parts%20...awing3.jpg
It wasn't noticeably cruddy.

It's now worse. Pump runs continuously when switched to 1, the boiler is not filling at all. Water runs back into the feeder tank, pressure is developing as normal on the pump gauge, water will flow from the group head if the lever is raised. So I'm guessing the Parker solenoid? Any other suggestion, especially on how to diagnose the issue further will be very welcome. I think I can find a solenoid locally, but most other parts will have to come on a slow boat from New Zealand!

I'm off to bed as it's 1 a.m. here, but will be on deck again in about 5 hours....

If you can brew with normal pressure, then the pump is good.. obviously. Use a voltmeter to be sure that the solenoid is getting voltage when the boiler fill is initiated. If it is, then the solenoid is stuck closed or burned out. Also, DO NOT SWITCH THE MACHINE to POSITION 2! You risk burning out the heating element.

Thanks Randy. Will give that a go and replace the solenoid if it is getting voltage.

Cheers, Tom

...additionally, you should be able to hear or (if you can do it safely) feel it click. Even a thin wood dowel held against it should transmit the "click-clack" of it opening and closing.

Any chance it is something as simple as air getting into the feed tube and the pump needing to be primed?

jkoll42

The original post stated:

DonTom wrote:It's now worse. Pump runs continuously when switched to 1, the boiler is not filling at all. Water runs back into the feeder tank, pressure is developing as normal on the pump gauge, water will flow from the group head if the lever is raised.....

I assumed that since the pump had enough pressure to open the OPV then it was probably working correctly. When the boiler is cold the anti-vacuum valve is (or should be) open, so the pump should not have to work very hard at all to fill the boiler. At least that was my assumption.

We are talking about a heating exchange unit correct?
air doesn't enter the system or I should say if it does the vibrating pump air breeder valve will expel it,

now 2 possible place to look at:
I'm assuming already that while the machine is trying to fill (you hear the pump running)
you DO NOT see the water level going down
(is getting turned around from the breeder valve/by pass correct?)
if so
check that the one way valve is not stuck close and lastly focus on the inlet solenoid valve as already mentioned by Randy

Thanks for all the suggestions guys. Have not had time today to attend to it: also need to buy a volt meter before I go hunt for a new solenoid. However, the solenoid does seem to go "click", so will look at the one way valve tonight.

Just to further clarify the current situation: the pump develops pressure, the water returns to the filler tank via the return tube. If I raise the lever to brew cycle position, water flows as normal through the grouphead.

Stefano, I'm feeling stupid. Which is the one way valve you're referring to? (best to give me the number on this diagram: http://espressocare.com/images/Parts%20...awing3.jpg ) By the way, is this from your company? Very useful, except I can't find a an index to put names to the numbers in this diagram...

And don't worry, I'm not switching the heating element on while these symptoms persist.

Believe it or not, I'm really enjoying the process (my wife is missing her flat whites however). I worked for a few years as a professional barista in Auckland, New Zealand, but never really got involved with the maintenance beyond back-flushing. I like to tinker, and intend to get into roasting beans and rebuilding machines further, with a eye to getting into roasting/distributing professionally in a few years.

FIXED! After getting sidetracked by the solenoid (which I found was fine), I did the (should have been) obvious, and looked for blockages.
The line from the solenoid valve and the right angle joint that mounts the inlet to the boiler was totally blocked with scale, barely a pinprick sized hole left for the water to flow in.
Now pickled in vinegar, cleared with a plaque scraper and re-installed. Waiting for the machine to heat up, be flushed, and start making the good stuff again.
Will be ordering some de-scaling chemicals, if they is to be found in this part of the world!

If there was that much scale on that pipe, the rest of the machine will be in need of similar service. This should be done before other failure points, like the heating element, are affected.