Hi everyone ...

It's been a while since I was on here and had to set-up a new account.

I have an Isomac Millennium which I purchased new in 2002. In 2010 I replaced a lot of electrical components and re-wired a lot of the machine. A few months ago it stopped boiling water so I just replaced the heating element and while I was in there, I rebuilt the E-61 and replaced a few other small parts (valve stems etc.).

1) I fire it up. Pump seems to pump forever. Only seems to stop if I pull-up the E-61 lever. The ulka pump is working, though does sound a bit rough. I can feel suction on the end of the intake.

2) As soon as I dump water through the group, pressure gauge drops (as it should), but rapidly. Pump does not kick-in again. Water will emerge from the water wand, but the pump doesn't re-engage and eventually the water turns to steam.

3) If left on (pump off), the pressure gauge eventually drops to zero. I have to turn the machine off, then on, and the cycle (from "1" above) begins again.

I've burned about 3 days on this and spent a lot on parts. Any suggestions on what's going on here?

Thanks so much everyone. It's been a super reliable machine and I've been able to repair any problem, but this one is baffling me. I can't take anymore french press coffee.

Previous re-build thread from 2010 (in case you're interested): Vacuum Breaker Problem - Isomac Millenium

part 1) could be that you've reconnected the power to the brew switch incorrectly, ie the pump is on when the lever is down and off when the lever is up. There needs to be one wire connected to the common spade and one to the NO (normally open) spade, not the NC (normally closed) spade

Redpoint wrote:Pump seems to pump forever.

It might be the boiler's level probe not sensing water. If you leave the pump working, and open the steam wand, will it finally have water running out of it?

You can remove the probe to check for deposits. Or test with multimeter - the resistance (between the probe and the boiler) should decrease from "open line" with the dry boiler to low resistance once the water touches the probe. This, of course, is only after disconnecting the machine from power line (I am sure you know that )

It also might be boiler's fill solenoid stuck/burnt/not getting juice from the controller and the water is not actually going into the boiler.

I would check the probe first (just test it with multimeter). And then the boiler's fill solenoid to confirm that the boiler is filling in.

Redpoint wrote:2) As soon as I dump water through the group, pressure gauge drops (as it should), but rapidly.

Why would pressure in the steam boiler drop, if you run water through the group? Or did you mean you run some hot water out of the boiler (through the hot water (tea) tap)?

Redpoint wrote:Pump does not kick-in again. Water will emerge from the water wand, but the pump doesn't re-engage and eventually the water turns to steam.

One more reason to check the water level probe.

Redpoint wrote:A few months ago it stopped boiling water so I just replaced the heating element and while I was in there

Did it look like it was overheated? Reddish glowing colour? Like here: Is it possible to tell how my heating element failed from looking at it?

If so, then the problem is definitely with the water level. I would also disable the heating element (e.g. by disconnecting hi-limit thermostat) for the time being, while you are solving the problem, so that it would not be accidentally damaged (it will burn out very quickly, if not completely submerged in water) if there is not enough water in the boiler.

Teflon1064 wrote:part 1) could be that you've reconnected the power to the brew switch incorrectly, ie the pump is on when the lever is down and off when the lever is up. There needs to be one wire connected to the common spade and one to the NO (normally open) spade, not the NC (normally closed) spade

I did not replace/touch the brew switch so it should be operational.

tonythewonderful wrote:It might be the boiler's level probe not sensing water. If you leave the pump working, and open the steam wand, will it finally have water running out of it?

You can remove the probe to check for deposits. Or test with multimeter - the resistance (between the probe and the boiler) should decrease from "open line" with the dry boiler to low resistance once the water touches the probe. This, of course, is only after disconnecting the machine from power line (I am sure you know that )

It also might be boiler's fill solenoid stuck/burnt/not getting juice from the controller and the water is not actually going into the boiler.

I would check the probe first (just test it with multimeter). And then the boiler's fill solenoid to confirm that the boiler is filling in.

I thought it was the probe at first too. I removed the probe (yesterday) and installed another one. I honestly have no idea if either works as I do not own a multimeter. I can probably borrow one. Is the probe supposed to be able to slide up and down within the bushing?

I've now made a riveting video that illustrates the behaviour (now different than yesterday): take a look. You might want to fast forward here and there as I didn't cut the footage. Basically: the pump goes on, for a long time, a minuscule amount of water passes through the E61, and now it's not heating-up. This is different behaviour than yesterday, but very similar behaviour to what happened a few months ago when it wouldn't heat-up (the very behaviour that lead me to repairing it in the first place).

Redpoint wrote:I do not own a multimeter. I can probably borrow one.

Yes, please borrow one. Or buy some cheap one. You do not need any fancy-high-presicsion-gold-plated-clumps stuff. They all will be able to measure voltage and resistance, better if there is also a circuit tester, that is a buzzer that sounds when you have a closed line - will help to trace/check all the connections.
Without it you will be guessing and wasting time:

Redpoint wrote:I honestly have no idea if either works

And no one will be able to tell.

Redpoint wrote:Is the probe supposed to be able to slide up and down within the bushing?

Yes, this is to adjust it slightly, to have the heating element covered, and still head room for a nice dry steam.

Redpoint wrote:now it's not heating-up.

Oh, no!!! I think I might be too late with "disconnect the hi-limit thermostat". One more reason to borrow/buy a multimeter to test if the heating element is still alive. Since you are buying/changing/upgrading so many things in your machine, I do not understand how you were able to pull off all that without a multimeter.

Redpoint wrote:the pump goes on, for a long time, a minuscule amount of water passes through the E61

I'll check the video later today. For now, let's forget about the E61 group,and find out if any water goes into the boiler.

To avoid any further damage, I strongly recommend you get a multimeter, and disable the heating element before any further tests. Otherwise you might well buy a new machine - you have already changed/replaced/upgraded enough.

The video was somewhat helpful:

1. So, the pump does stop eventually after initial power on. I would check boiler fill solenoid. Can you hear it click when you switch the machine on? (it was not very clear on the video). Things to check: voltage on it's contacts, it's coil, if they are OK, then I would remove the solenoid to check that it's valve is not stuck.
2. The heater light (red on the right) was always off. Water level/PSTAT. There is a very slight hope the element itself is still alive.

3. Another possibility is that the pump is dying, and simply does not pump water effectively.

Check out this electrical schema, it might not be exactly as in your machine (e.g. you might not have the solid state relay, only pressurestat), but still: http://users.rcn.com/erics/Illustrations/IS_ELEC3.jpg

Anyway, if you want to continue, please get a multimeter - you will not be able to check any of these without one.

Thank you so much for your replies. Just got a multimeter 5 minutes ago.

Will let you know when I manage to tear apart the machine again.