Well, something is clearly still wrong here. It's idling around 195F, but peak temperature on a flush is only around 205F. I'm going to see if raising boiler pressure affects it at all.

Edits: Shots are pulling in the 202-204 range, so maybe everything is fine and it's just behaving a little different?

I suspect your descaling efforts have improved the thermosiphon circulation. The fact that your boiler pressure and steaming seem to be normal, per your comment (I have zero issues with boiler pressure and the steam/hot water acts normally when run.) indicates that your steam boiler temperature (directly related to steam boiler pressure) was normal. Certainly the steam boiler was had limescale, but the specific problem you had was almost certainly lack of normal thermosiphon flow to maintain the grouphead temperature, which would more likely be caused by limescale in the HX or in the orifices enterring and leaving the upper and lower water ports to the E61.

New, odd behavior. The machine after power on rises to the correct temperature and idles for a while at around 205F. However, if left on idle for a longer amount of time, it starts to plummet. The machine has been on for 2-3 hours and has fallen to 150F. Any ideas on what may cause this?

In the event that someone else with a similar issue bumps into this thread, I'm going to continue to document my progress here.

I opened the machine, as some of the other threads where an HX machine hit appropriate temperature at the grouphead, but then the temperature fell, pointed to a potential issue of a leak in the connections.

Found a leak immediately:
I'm working now on how to address the leak, but hopefully this is the end of my issues.

A couple pictures for reference:

I noted a drip coming from the grouphead, which was an indicator of a potential leak:



Here's a non-video of where the leak appears to be (not sure how it could matriculate to the front of the machine, but one issue at a time I suppose:




I also noticed some water here:



Not sure what this is, either, but documenting for potential issues.

Removed the fitting, cleaned the area, replaced the fitting and the leak went away. And now the grouphead is peaking at 120F temperature. I think I'm going to send it out for repairs.

OP, did you ever figure out a root cause for the low tempera rate and a corrective action?

Nope! I gave up and found a local tech.

CrystalRed wrote:OP, did you ever figure out a root cause for the low tempera rate and a corrective action?

With a leak like that at the upper HX connection...
The problem is that heat exchanger leaks. Steam quickly displaces and replaces the liquid water in the upper parts of the thermosiphon loop. The remaining liquid water, much heavier than the steam, can not climb up to leave through the upper HX port so the thermosiphoning action stops.

Sorry for misleading you with my belief that it was calcium related. I didn't expect an external leak like that.

No worries. I found a local tech who took it in because they wanted E-61 experience. They took the whole thing apart and it was used as a teaching tool in an SCA class. They had it for a few weeks and apologized and comped the service. Couldn't be more pleased with how it shook out.