What can cause a heating element to fail mid boil?

I have built the countertop Brutus system that jkarp has so graciously outlined here. Yesterday while brewing a stout, the element burnt out in the middle of the boil. I turned the PID down to 95 in manual mode and it quit on me. Luckily I could finish on the stove, but the boil was not as vigorous for the last 15 minutes as I would have liked.

There were a few bits of grain in the boil that snuck through from the mash. Could a bit of grain stuck to it causing a hot spot? Otherwise, I am clueless.

The element was black after I drained the kettle and the outer layer chipped off very easily exposing bright copper underneath. There was a little nick in the surface of the element where it appears to have burnt through.

I already had to replace the first one (my fault) and this is very frustrating. If I have to replace the element every time I brew, I'm not going to get much brewing done.

Holy smokes! Where'd this element come from?

There was no smoke.

Menards. I'm going to try the one at HD or ACE this week. It worked perfectly in all 3 of my test runs and auto tuning sessions.

lilbastage already taken?

smellysell said:

lilbastage already taken?

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PM sent. But, yeah, it's me.

Get the low density (physically larger) ones. Sometimes they can even handle dry firing!

Use an ohm meter to measure resistance between a screw terminal and ground. (Well, each terminal now that it's broke.) Maybe short to ground causing hot spot?

OhioBrewingTechnologies said:

Get the low density (physically larger) ones. Sometimes they can even handle dry firing!

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Unfortunately, low density 2KW @ 120V are nearly non-existent.

OhioBrewingTechnologies said:

Get the low density (physically larger) ones. Sometimes they can even handle dry firing!

Use an ohm meter to measure resistance between a screw terminal and ground. (Well, each terminal now that it's broke.) Maybe short to ground causing hot spot?

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I would, but I don't have access to 240v in the kitchen. I'm not sure I could run it at 120v and still get the power to boil that I need. Do they make 8000kw elements?

I'd do the test, but I really don't want to try to dig the screw terminals out of the epoxy just to figure it out.

Is it possible the wort scorched and coated the element causing the failure? There was no burnt taste or anything to the wort or even the black crust that flaked off (and it was very thin).

I've kept an eye open for 8KW 240V myself, but no luck. My out-of-the-ass guess is, this brand element didn't like the slightly acidic wort and corroded.

I don't the answer to your problem. But I remember seeing this earlier in another thread. Atleast you might be able to find something better. Hope it helps.


https://www.homebrewtalk.com/f51/rims-dummies-114997/index3.html

Look at post #21.

I suppose if I paid attention to the fact this was a brewtus system I wouldn't have suggested such a thing.

Was the element "puffed up" at all? Was it easier to bend or squish than normal?

OhioBrewingTechnologies said:

I suppose if I paid attention to the fact this was a brewtus system I wouldn't have suggested such a thing.

Was the element "puffed up" at all? Was it easier to bend or squish than normal?

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After all the black flaked off it left the very shiny copper and it was VERY easy to bend. It was not puffed up at all.

the_Roqk said:

I don't the answer to your problem. But I remember seeing this earlier in another thread. Atleast you might be able to find something better. Hope it helps.


https://www.homebrewtalk.com/f51/rims-dummies-114997/index3.html

Look at post #21.

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Thanks, I'll take a look.

Interesting. I have a different element with black junk all over it. Wondered what it is. It hasn't failed yet but I can't get it off with BKF, scrubbing, or any other reasonable means. So I see no copper. And it's no harder to bend than before.

I've failed a few elements on purpose and after the loud boom they are very easy to squeeze and bend. Maybe just...try a different brand.

If you're willing to build something, how about this. Each element gets 1000 watts, so you split the power evenly. (Hope the attachment works out....?)

I think these will work for diodes, but even the 16-amp version might be OK and it's half the price.
http://mouser.com/search/ProductDetail.aspx?qs=Gev%2bmEvV0iYKInyPofK/gw==

Better put them on a heatsink though.

OhioBrewingTechnologies said:

Interesting. I have a different element with black junk all over it. Wondered what it is. It hasn't failed yet but I can't get it off with BKF, scrubbing, or any other reasonable means. So I see no copper. And it's no harder to bend than before.

I've failed a few elements on purpose and after the loud boom they are very easy to squeeze and bend. Maybe just...try a different brand.

If you're willing to build something, how about this. Each element gets 1000 watts, so you split the power evenly. (Hope the attachment works out....?)

I think these will work for diodes, but even the 16-amp version might be OK and it's half the price.
http://mouser.com/search/ProductDetail.aspx?qs=Gev%2bmEvV0iYKInyPofK/gw==

Better put them on a heatsink though.

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I really appreciate the thought you put into that, but I'm afraid that's outside my comfort zone.

I guess I'll just try a different brand and cross my fingers. It's entirely feasible I just got a bad one. The first one burning out was totally my fault (I let it run dry), so it may have lasted me forever if I had paid better attention to what I was doing.

How about one of these for the Brutus 20? 6000 Watts at 208 V will give 2000 Watts at 120, and the watt density should be pretty low. These guys have a pretty good assortment of other heating elements too...

http://www.lockeplumbing.com/detail...60&r1=WHE-USS25C&r2=GRU-595916&r3=FEI-NL9-LED

I just replaced mine with a different brand. This one seems much better made. It's almost chrome plated in appearance. The other was just copper.

OhioBrewingTechnologies said:

How about one of these for the Brutus 20? 6000 Watts at 208 V will give 2000 Watts at 120, and the watt density should be pretty low. These guys have a pretty good assortment of other heating elements too...

http://www.lockeplumbing.com/detail...60&r1=WHE-USS25C&r2=GRU-595916&r3=FEI-NL9-LED

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6K @ 240 is 1.5K @ 120...

jkarp said:

6K @ 240 is 1.5K @ 120...

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Right, but he stated 6000W at 208VAC, which WOULD be 2000W at 120VAC

I am really surprised that an element failed like this. Grain bits wont matter, I dont think that will cause something like this to fail. There is a chance that it was simply a defective element, there is that chance.

If you have a 6000W 208VAC element, it would be 2000W at 120VAC and would suffice. Though, many people use HWD elements in boiling applications and have no issues at all, so I dont know that it will matter.

most likely what happened was that the thick stout wort allowed cavitation to occur around the hot element, basically it dry-fired underwater surrounded by a gas bubble causing a meltdown.

water heater elements are designed to operate under pressure, which elevates the boiling point of the liquid in contact with the element. without that pressure, the element can easily overheat, especially if it has low mass. a 2kw 120v element would fit that bill.....

The Pol said:

Right, but he stated 6000W at 208VAC, which WOULD be 2000W at 120VAC

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Whoops, I misread. 208V is 3-phase. That's...weird...

I'm pretty sure what they mean there is to put it across two of the three 120-Volt phases. That's where 208 comes from.

But for all we know it's the exact same element as their 120V 2000-Watt model.