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.

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?

kanoyu wrote: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

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.

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?

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.

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.

kanoyu wrote:- 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

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

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.