week 3+ with S1; grounding wire issue

[jbb]

as some of you have been following, I've been working on an older V1 trying to get it up and running. Had it put together with a new pump, descaled boilers, even lubricated the ball joint on the steam wand (that was a big improvement). But now there is a new problem.

After assembling, during the leak test I noticed a hissing/popping spittle type of sound from the top of the steam boiler. The sound is only present during a boiler heating cycle. If I place a small drip of water on the boiler lid it produces a similar sound. So I thought it might be the vacuum breaker valve not seating properly, and I removed and disassembled it. the o ring maybe had a slight compression on one side, but overall didn't look too bad. So I lubricated the o ring and reinstalled. if i push and release the valve when the boiler is under pressure it seems to snap shut correctly. In any event, messing around with the vacuum breaker valve did not make the popping noise go away.

in the course of trying to figure out what else it might be I noticed that one of the green and yellow grounding wires attached to the boiler had a blackened section. Below is a picture and a blow up of the top of steam boiler that I took prior to disassembling the boiler for the descale; the arrow points towards the problematic wire. In this photo, the insulation looks perhaps a bit discolored. So this problem, or at least an early stage of it, may have existed before disassembly. Whether the wire is causally related to the hissing/popping sound or not is unclear, at least to me.

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Here is a shot of the wire after removal. It seems as if there may be two places where the insulation has been damaged (arrows)? So, my question is whether this is just that the wire has been placed too close to the boiler lid, leading to overheating the insulation? Or is it indicative of a more serious electrical problem?

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Thanks for any diagnosis/advice. As I have come to be in the habit of saying, your help is so greatly appreciated. This site is definitely a value added part of going with an S1.

[slo]

The insulation wire is just discolored by the heat from the boiler. These are not spark marks.

For the sound, my Vivaldi always hisses and spits when heating up. Just before the vacuum breaker shuts. This is normal. This wll results in some of the water drops to evaporate but I have never heard any sounds from those.

[jbb]

Thanks for your response. Sounds like the spittle sound is just part of the boiler's breathing cycle. I guess for some reason I did not notice it before.

I rearranged the grounding wires as shown to minimize exposure to the boiler. The damaged wire definitely does not feel as supple as the other one.

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I guess the issue for me is, given that it feels different, can I simply reconnect as shown and proceed with safety, or should I do something more extensive to repair or replace?

Just as a fun picture, I pulled my Silvia's boiler for maintenance during these repairs. Here's a side by side comparison of the Silvia and Vivaldi's boilers.

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[Endo]

Good job. I like seeing all the photos too.

Just take that Artazza cup off the top! It's making me nervous.

[jbb]

Just take that Artazza cup off the top! It's making me nervous.

What, out here in SoCA? Kids are always calm and sedate; must be something in the air. And the ground-steady as a rock!

[slo]

I guess the issue for me is, given that it feels different, can I simply reconnect as shown and proceed with safety, or should I do something more extensive to repair or replace?

Personally, I would just move on. The only problem with baked insulation is that it may crack and crumble eventually. If the wire does not come in contact with a live source (it is a ground) there is no issue.

[jbb]

The only problem with baked insulation is that it may crack and crumble eventually. If the wire does not come in contact with a live source (it is a ground) there is no issue.

Thanks Slo. That's reassuring for me.

Before wrapping her back up, last night decided to do some temp readings and check the heating cycle with the new insulation. given that the wire had been in the same place before descaling/insulating the boiler (including cleaning scale off the temp probe), I was also wondering why it might be starting to get cooked now. so inserted a tc probe below the terminal of the damaged wire and monitored temp over 5 heating cycles. graph is below; unfortunately don't have similar data from before the descale/insulation project.

at this location temp range pretty tight between 116-118 C.
Average time heater was on; 11.8 sec +/- about a sec.
Average time between heater cycles; 2 min 42 sec +/- about 2 sec. I think that's in the ball park of what others have reported after insulating the boiler.
Ambient temp 18 C
Cup holder temp about 40 C.

So, out of curiosity, is that what people would expect to see in terms of the actual temp on top of the boiler? Any reason to think that cleaning/insulating would change how hot the boiler runs or how temp is distributed within the boiler? seems unlikely i guess; internal temp should be set, lid temp should not be more hot, just overall rate of heat transfer from the boiler slowed.