E61 Salvatore troubles with low brew water temperature?

[kanoyu]

Under the following circumstances, the grouphead temperature (as measured by EricS's grouphead tc device) and brew water (as measured by a Scace device) on my E61 heat exchanger Salvatore begins dropping, ultimately stabilizing at around 129 DegF:

- long flush (to about 205 on grouphead tc device)
- following second shot after long flush (above)

If I just pull one shot after the long flush, do a wiggle rinse, and a backflush, the temps seem to rise back up to 212 very quickly. If I pull two shots, I really have to be quick or the temps start to drop and I have one heck of a time getting them to rise again.

This isn't just a grouphead issue. When grouphead temp was 129 DegF this morning, I used the Scace to measure brew water temps, which were as follows:

0 sec: 128.7
5 secs: 134.5
10 secs: 138.9
15 secs: 141.8
20 secs: 145.4
25 secs: 148.9

pstat (Sirai) is at 0.95 to 1.15. The machine has been doing this as long as I can tell (since I've been using the Scace and then grouphead tc devices).

Once the temp has hit bottom (129 DegF), I can flush 4-6 oz to get it rising again. If it is on its way down, there is very little I can do other than flush 2 oz at 20-30 second intervals. The water from the boiler (via the hot water spout and the steam wand) is boiling/steaming.

My questions are:
Is this 'normal' for an E61 heat exchanger?
If so, are there any 'workarounds' that you know of?

Finally, I'm not particularly mechanically inclined (installing the grouphead tc device in a covered E61 was about the extent of my comfort zone), but if you have any ideas/suggestions, I'd appreciate it/them.

Thanks.

[cannonfodder]

I sounds like you have a sticky pstat and it is not kicking in but you should notice that with a big drop in the boiler pressure gauge. It could also be a side effect of some severe scaling in the boiler and grouphead. When was the last time you descaled the machine?

[HB]

My questions are: Is this 'normal' for an E61 heat exchanger?

Not at all. I agree with Dave, sounds like scale buildup. For reference, the pictures below show a clean and two not so clean E61 "mushrooms":


No scale buildup


See Sputtering e61 & HX scale build-up - Cured! for more details

[erics]

It is absolutely NOT NORMAL. Group temp as measured by the thermocouple in the adaptor is typically ~ 212 F after a 45 minute warmup.

There is no quick workaround to this but there may be a very quick fix. My fingers are crossed.

It seems to me as though you have a hit & miss situation with the pressurestat contacts. Salvatore (I believe) has always used Sirai pstats which have three sets of contacts but only one set is used. See below pic which is borrowed from a recent CoffeeGeek post & thanks to this forum's moderator, Jeff S., for tipping me off to the post. The link to the CG post is here - the OP from CG has done anyone looking at Salvatore machines a big service.

http://www.coffeegeek.com/forums/...so/machines/290882



With the machine unplugged, remove the cover and you should easily notice the pstat. The pstat cover is simply held in place by the screw in the middle just above the yellow pressure adjustment screw cover. Remove the cover and simply(?) move the wires to the set of contacts next to the existing wired pair.

Much easier than installing the adaptor.

[jesawdy]

I am also curious, does your HX design (all that brass business on top of the boiler) look like the one in the pic above, or different?

The deadband you see on the Pstat is typical (not tight, but typical) and would indicate to me that the pstat is working.

Either your heater is not heating well (and Eric's idea of checking the Pstat and contacts is a good idea) but it is obviously heating some, or your thermosyphon loop is not syphoning/looping. The loop could be clogged by scale in the loop, the group or the HX. I have to say that I am not struck with a "wow, that looks efficient" feeling when I look at the thermosyphon loop on the Salvatore, but I would think it should work.

One last idea... I do not see a vacuum breaker on the Salvatore from the pics recently posted on CG, so you might have false pressure in the boiler and you are not truly to temp.... Are you leaving the machine on? Do you relieve false pressure in the boiler via the steam wand on startup? Do you have a vacuum breaker valve in yours?

[cafeIKE]

I had a similar problem on the Vibiemme, but it is due to thermosyphon stall :

On the Solis SL-90 I would run a small cleaning flush of a second or two after each shot after removing the PF.
When I got the Vibiemme, I continued the practise.

If the cleaning flush is longer than about 4 or 5 seconds, there is no thermosyphon stall. Less than that and the thermosyphon stops. The water in the boiler is still about 250°F, but the thermosyphon inlet temperature can drop to below 180°F from the normal 230°F.

[kanoyu]

Wow! Thank you all for your quick replies and suggestions. My first reactions are:

- after about 45 minutes after startup, grouphead temp is 212, and rises to 215-17 or so in early stages of the flush
- my machine is not (yet) plumbed in and I have been using Crystal Geyser since day 1 (about a year ago)--water is really hard here in my neck of SoCal
- I have not descaled, but clearly that is my first order of business (a process that will challenge my capacities, for the boiler, anyway)
- I am reluctant to think that the pstat is the problem because, even when brew water/head temps are low, I get plenty of steam and sputtering/steaming water from the respective hot water/steam wands. Activating these wands does nothing to raise the temperature of the group head or brew water.
- my set-up is exactly as pictured in Eric's post
- I'm pretty sure my Salvatore does not have a vacuum breaker, but, per instructions, I turn the machine on with the steam wand open and close it when it starts to sputter (and I'm constantly opening the steam wand during my 'routine').
- I can't comment on the efficiency of the thermosyphon, but I suspect that this maybe a problem. Whether it is a design problem or a scaling problem, I won't (begin to) know until I descale
- I am still befuddled that I now know how to make the machine cool down and how to keep it hot. I can't prevent it from cooling without using a lot of water or adjusting my timing, which is the most frustrating (since I have to do A LOT of work to make an espresso if I want one 5-10 minutes into the cooling process). I DO need to descale, but the predictablility of the heating/cooling suggests to me that I'm missing something else....

Anyway, thank you ALL for your help and suggestions.

[cafeIKE]

- I have not descaled, but clearly that is my first order of business (a process that will challenge my capacities, for the boiler, anyway)

This may help
Simplified HX Descale

[jesawdy]

Before you descale, I do think it would be prudent to pull the "mushroom" as suggested. As you can see in the picture below (from E61 Group Espresso Machine: Detailed Interior Schematics), the "mushroom" (labeled Upper Sleeve Assembly in the picture) sits near the grouphead HX inlet/oulet and would affect the thermosyphon loop if scaled heavily like some pictured earlier. I think it would be helpful to know what this part looks like before you descale.


E61 cross section - Drawing from Verna Design, Inc., annotations from EricS

[kanoyu]

So if/when I pull the 'mushroom', does the rest of the grouphead collapse into a heap of parts? Or can I (attempt to) remove it and then just put it back in? I am assuming, only from the pictures, that all I need is a big wrench. What else might I need?

Sorry for what are obviously newbie questions, but I'd rather ask now than when I have the machine in pieces all over the kitchen counter and floor.

Thanks again.

[jesawdy]

I don't think so... looks like you need a 36mm wrench per here:

Park Tools USA makes a 36 mm closed-head wrench (PARK HCW-4) for working on bicycle cranks and bottom brackets that fits perfectly on the large nut attached to the E61 'mushroom' of my Andreja.

http://www.parktool.com/products/...?cat=25&item=HCW-4 (I have no connection to Park Tools, other than using their tools on my mountain bikes.)

You need to loosen the larger of the two fittings seen on top of the grouphead in the pic below, the top one gives access to the gicleur and filter screen.


Salvatore E61 grouphead, top

I think you'll just pull it straight out after loosening.... You may wish to protect the chrome with some masking tape.

I'll let someone that has done this already chime in, please. (no E61 here)

[miKe mcKoffee]

I think you'll just pull it straight out after loosening.... You may wish to protect the chrome with some masking tape.

I'll let someone that has done this already chime in, please. (no E61 here)

Yes unscrew lowest large nut counter-clockwise, then lifts right out straight up. (No, the remaing group doesn't fall apart. ) I don't have a fixed or adjustable box wrench large enough so have used channel lock plyers no problem, covering the teeth grips with a couple layers of electrical tape first to protect the chrome.

Be very careful with the white nylon(?) gasket! You may or may not be able to re-use it without a leak afterwards, especially during machine warm-up.

[erics]

Another option would be to find a "friend" who has an old Volkswagen repair shop - 36 mm is the size of the axle nut and flywheel nut for the older air cooled bugs.

I believe it to be a very good idea to R & R this "mushroom" piece regardless of any other outcome. HOWEVER, before you remove the mushroom, remove the smaller nut (22 mm) which will expose the gicleur screen. It will also reveal the little gicleur which is firmly screwed into the mushroom.

Using two paper towels over the chrome should also suffice to prevent any scratches but as your group is semi-concealed, it is not AS critical. Soaking all these parts in white vinegar overnight will remove most scale.



I still think it is a pstat problem (hit & miss) and there again, it would simply be good practice, regardless, to move the wires over to a "new" set of contacts.

I would tell you to measure the water flow from an empty PF but the last time I advised someone to measure something, he took a maul to his PF & basket -

I simply don't have any idea what you would do -

If you want these tools, email me off line and I'll send them for postage.

[jesawdy]

Another option would be to find a "friend" who has an old Volkswagen repair shop - 36 mm is the size of the axle nut and flywheel nut for the older air cooled bugs.

Ha! I have run across something else like this in the past..... AutoZone or the like probably sell the 36mm socket individually, I got mine that way years ago... the only big socket I own. Guess I'm ready when I get an E61.

[mgwolf]

Hi. Lots of good suggestions. If all else fails, you could certainly call Salvatore. I've heard they have excellent support and their machine is warranted for 6 years, I believe. Michael

[espressme]

Hi. Lots of good suggestions. If all else fails, you could certainly call Salvatore. I've heard they have excellent support and their machine is warranted for 6 years, I believe. Michael

my 1¢
Wendy and Salvatore are more than happy to help anyone that comes as a student and respects their machine. Be able to call back when you call as they are often very busy. Wendy does the emailing but Salvatore will often write back with an answer. Leave a well formed question if they are, and they will get back to you. I've had very good experience with them.
Sincerely
richard / espressme
My Craig's List Salvatore is in a line for a rebuild at home. With genuine Salvatore parts and information "Salvatore" has furnished at a reasonable cost!

[HB]

I had a similar problem on the Vibiemme, but it is due to thermosyphon stall...

Would you elaborate? I've never heard of a "thermosyphon stall."

[kanoyu]

Again, thank you all for your help. This is by far the longest post that I have initiated. I certainly hope that others can also learn from all that is being revealed here.

So I think I have this straight:

First, use 22 mm wrench to remove the small nut on top (to expose the gliceur screen).
Second, use a 36 mm wrench to loosen the lower of the larger nuts and remove the 'mushroom.' (Is that one nut that moves together, or is one a locking nut?)
Third, soak 'mushroom' overnight in white vinegar.
Fourth, reassemble.
Fifth, move wires to 'new' set of contacts on pstat.
Sixth, descale HX (and boiler).
Seventh, pray everything will work better than before.

BTW, I have contacted Salvatore a number of time since purchasing my machine last spring. The first was to get some more guidance on flushing and the second to ask if Mr. Salvatore would install Eric's tc grouphead device. Help was limited, and I was told I would void the warranty by adjusting the pstat and/or installing the tc device. Since I have done both, I now know I'm pretty much on my own.

[cafeIKE]

I had a similar problem on the Vibiemme, but it is due to thermosyphon stall...

Would you elaborate? I've never heard of a "thermosyphon stall."

Dan,
First, let me take this opportunity to thank you for a great forum. Grazie mille!

Perhaps the term is inexact, but as you can see in the graph, the temperature in the thermosyphon drops like a stone. The first time I experienced it, the espresso was so sour, it was unbelievable. Perhaps the most sour in almost 4 decades.

As sour equates to low temps, and the machine was new, the boiler pressure was ~1bar, the Parker was clacking every 150 seconds, 10 on, 140 off, there is almost unlimited steam and the external boiler temperature remained constant about 245°F, I added a TC to the thermosyphon inlet and outlet of the group. The graph posted is but one example of the symptom.

After much consternation, several false starts and help, I happened upon the idea that the only thing that could cause the temperature of the group to drop when the boiler was at temperature was the thermosyphon flow was "stalled." No hot water flow is replacing the heat lost due to radiation from group.

My 'guess' at the cause:
When a short cleaning flush is run, the upper chamber of the group drains into the empty pre-infusion chamber. If the pump runs for only a very few seconds, the upper chamber the does not refill. As there is no drag of the flow exiting the thermosyphon, the thermosyphon enters a resonant state and stalls. No less a luminary than Michael Teahan concurs.

I recently added Eric's TC/TM adapter set and have confirmed that it is possible to cause the group temperature to drop as in the graph at will by running a short cleaning flush after pulling a shot.

The next test is to leave the puck in the PF and run a short cleaning flush just before pulling the shot.

Note : the Vibiemme has a flow restrictor in the upper thermosyphon tube. Before I discovered the root cause, I was prepared to adjust the diameter of the orifice and /or thermosyphon injection point. The point is now moot.

[HB]

First, let me take this opportunity to thank you for a great forum. Grazie mille!

You're very welcome. Truth be told, most of the time I'm having so much fun, it's surely illegal in some states.

My 'guess' at the cause:
When a short cleaning flush is run, the upper chamber of the group drains into the empty pre-infusion chamber. If the pump runs for only a very few seconds, the upper chamber the does not refill. As there is no drag of the flow exiting the thermosyphon, the thermosyphon enters a resonant state and stalls. No less a luminary than Michael Teahan concurs.

Hmm-m. The interior of the upper chamber drains, but the exterior "sleeve" of water that makes up the thermosyphon can't:



The only exit from the thermosyphon loop is through those four tiny holes leading to the gicleur (yellow) between the outer and inner sections of the upper chamber ("mushroom"). Perhaps the pump is somehow introducing air into the thermosyphon? A large enough "bubble" could stop the natural circulation from re-establishing itself.