I have an 8 year old Andreja Premium that I love and can make consistently good espresso once or twice a morning I use Eric's digital thermometer adapter in the E-61 group. In June I turned the machine on in the morning as usual and several hours later the grouphead temperature was only in the 180's when it is normally 210-211. When I did a cooling flush there was no water dance and I could quickly pass my hand through the stream without being scalded - so I assumed that the actual temperature was about what the thermometer said. I turned it off and back on the next morning with the same result. I took it in to my local shop (Espresso Wrench) and they changed my pressure stat after I convinced them that I knew the water was not hot enough. They thought maybe something was wrong with the thermometer, it I don't think anybody was brave enough to stick their hand in the stream

About a month later the same thing happened and out of desperation I drained some water from the hot water wand and the steam wand and the temperature slowly went back to 211.

Same thing happened this morning with the same recovery result after emptying some water from the wands.

The only thing I can think of is something like a vapor lock in the syphon. I do not regularly make cappuccinos or Americanos so I neglect my steam wand and hot water wand and flushing them seems to solve the problem.

Has anybody else experienced something like this? Would a vapor lock be possible or is there another explanation?

Jim

Usually, that's a sign of a slight leak in the thermosyphon water circuit - somewhere.

In my case, on my Anita (which has a lot of similarity) it was the bottom fitting of the heat-exchanger on the boiler. The HX fittings seem to be the weak point of the Quickmill design. Over the years, my top fitting leaked and then the bottom one. Fixing the bottom one was quite an exercise of tearing down the machine nearly completely. But the fix itself is pretty easy: Remove the large hex fitting, wrap it with several layers of teflon tape to seal it. Then the task of putting it all back together again.

I think if you open it up and examine the fittings and plumbing carefully, you'll probably find the tell-tale signs of a slow leak at one of the HX fittings.

I would guess you have a problem with the boiler's anti-vacuum valve.
My MCAL, that has no av valve, behaves the same way. The gauge reads full pressure until you release the "false pressure" (open steam wand) at which point the reading drops by half (ish) and it slowly creeps back up to where is should be (for real this time).
What reading do you get from the steam manometer when you open the wand?

Probably not an issue with the boiler. If there's steam pressure in the boiler, it is fine.

If the e61 is going cool, it means the water level has dropped in the e61-to-heat-exchanger water circuit and it is no longer circulating water. The symptom is exactly what the OP described, after several hours, the e61 brewhead is inexplicably cool. You can probably even touch the top nut on it without burning your hand.

I've seen it twice over the years with my Anita - which shares exactly the same water circuit with the Andreja. The leak was really slow. It would take hours for it to show the problem.

Pull the cover off the machine, look over the large fittings on the top and bottom of the boiler which lead to the brewhead. Dime to donuts, you'll fine a trail showing where it is leaking. If it gets bad enough, you might see some water just trickle if you put a blind filter in and activate the pump.

The top fitting is fairly easy to fix. The bottom one is a bear. The bottom fitting is the same one the big bolt is screwed into from the bottom panel of the machine.

nuketopia wrote:Probably not an issue with the boiler. If there's steam pressure in the boiler, it is fine.

You're likely right, but...

Can someone please explain false pressure?

How are vacuum breaker valves supposed to work?

It's not clear whether the op's machine is getting to full temp then losing heat, or if it's cold until the wands are cracked open.

The fact that steam/hot water needs to be cracked open to get to full heat says vacuum breaker to me. Maybe it's staying closed. Scaled up?

Either way the op has some stuff to work with now, and I'm looking forward to hearing what the resolution is!

ecuew wrote:I would guess you have a problem with the boiler's anti-vacuum valve.
My MCAL, that has no av valve, behaves the same way. The gauge reads full pressure until you release the "false pressure" (open steam wand) at which point the reading drops by half (ish) and it slowly creeps back up to where is should be (for real this time).
What reading do you get from the steam manometer when you open the wand?

My boiler pressure is 1.3 - drops to 1.05 wen I open the steam wand and then quickly returns to 1.3. Mine sounds different and certainly has lots of pressure. Next time the grouphead goes cool I'll try to check the boiler pressure. Thanks!

nuketopia wrote:Usually, that's a sign of a slight leak in the thermosyphon water circuit - somewhere.

....

I think if you open it up and examine the fittings and plumbing carefully, you'll probably find the tell-tale signs of a slow leak at one of the HX fittings.

Thanks, I'll open it up and take a look. I am a little reluctant since it only happens once a month or so and I'm not very handy. I'll report back with what I find.

Yup - on the Adreja and Anita, the HX (brew water) circuit is isolated from the steam boiler circuit by a diverter valve and a check valve. When he cracks open the water or steam wand, it usually activates the water pump to replenish the boiler. This will also recharge the HX/brewhead water circuit with fresh water at the same time.

Another experiment is upon finding the brewhead cool, is to just activate the brewing handle on the brew group and run some water like you were flushing it. You'll probably notice that within a few minutes, the temperature will start to return to normal in the brew group.

I get not everyone is mechanically inclined. Be careful when taking the cover off the machine - be sure to unplug it first!!! Take your time and be careful not to scratch the finish.