Bosco heating element leak has me stumped...

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#1: Post by sheedapistawl »

Hello friends!

Dealing with a leak in my Bosco and for some reason I cannot seam to resolve it :(

I had an element gasket leak, it rusted the bottom frame a bit as well.

Photos of the element and seating:

The boiler gasket looking a bit ??? At the moment it seems to be fine so I'm inclined not to deal with that (also since I do not currently have a boiler gasket...)

And I think the corrosion at the ground terminal is a wet cup dripping there from the top (cleaned up, don't hunk it's another issue?).

Post cleanup:

Some other photos:

I removed the rust with 150 and 400 grit sandpaper.
Taped down the entire area, rustoleum over the formerly rusty bit to seal. Removed the element and put in the new gasket, at no pressure this is the leak and at high pressure it's a LOT faster.


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#2: Post by JohnB. »

Can't snug up the element cover a little tighter? Was the sealing surface on either cover pitted or damaged at all? I've had good luck with that type of seal on my Speedster. Never required any sealer.

Team HB

#3: Post by ira »

I can think of a few possibilities.

You are not tightening it enough. (I assume unlikely, but how are you tightening it?)
One of the gasket surfaces it scratched.
There is a pinhole in the brass casting.

I would get a magnifying glass and a good light and examine that area of the boiler closely. I'd also consider pulling the end of the boiler off to fix that other leak around the bolt.

sheedapistawl (original poster)

#4: Post by sheedapistawl (original poster) »

Thank you for the response!

I don't currently see any leak around the bolt. There is some different metal contact corrosion but overall seems fine.

I torqued the element quite hard I thought by gripping that big nut (inside which you see those contact terminals) with a big Knipex. I torqued it until the whole boiler moved slightly. That said when I removed it it was shockingly easy to untorque.

Some more photos of the seating.

Any way to get the seating on the lid smooth? I used 140 or 400 grit sand paper maybe that causes an issuer? Maybe I do 400->1000->2000?

I also don't see the gasket sit centered when it is torqued maybe there is a way to center it on the seat , gravity pulls it a bit down and there is play

Team HB

#5: Post by ira »

Big socket and impact is likely the only way you'll get it tight enough and the proper way to remove it.


#6: Post by mikel »

Hi Riz,
One thought would be tightening through multiple heat/cold cycles. I usually tighten after cold, but you could try unplugging after hot cycle, and then tightening a little while warm.

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#7: Post by mrgnomer »

The limited experience I have with boiler elements is that they're screwed in with either thread sealant and/or a lot of torque. My boiler needed an impact wrench to unscrew the element which implied loctite or high torque installation.

You could try thread sealant or more torque to stop the leak. The threads of your element look like plastic. If they are I'd be careful with the torque. If you can find factory specs they could give you the torque recommendation for the boiler element.

The gasket looks similar to the teflon mushroom top one on an e61 group which works well when new to seal but over time stretches out from heat and compression.
LMWDP #116
professionals do it for the pay, amateurs do it for the love

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#8: Post by mrgnomer »

Looked closer. Threads look more like black iron pipe.

Those threads are typically tapered and crush together when tightened. If they're the source of the leak further tightening usually stops the leak.
LMWDP #116
professionals do it for the pay, amateurs do it for the love

Team HB

#9: Post by ira »

that does not seal on the threads, it seals on the Teflon gasket. Teflon is rather hard and requires a significant amount to tightening to get it to seal. Without pulling the boiler out and building a suitable clamp to hold the boiler without damage, an impact wrench is pretty much the only answer.

sheedapistawl (original poster)

#10: Post by sheedapistawl (original poster) »

Plan to message bosco as well, thank you all for weighing in!

I am inclined to try more torque with my 12" knipex, covered with insulation tape on the teeth to prevent marring, and hand on boiler to brace to not cause any stress elsewhere while torquing, and then t try hot / cold cycles of tightening until leak goes away.

Thoughts on sanding off the oxidation layer on the lid where the gasket seats? Was thinking light wet sanding 150,400,1000, 2000.