Domestic Coil Leak

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leward
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Joined: Fri. Jul. 03, 2009 2:41 pm
Stove/Furnace Make: EFM 520
Stove/Furnace Model: 1

Post Tue. Dec. 07, 2010 7:46 pm

Hello All:
I've joined the legion of girly men, changing from a hand fired bituminous monster to an EFM-520 --Oh lazy days. However, I discovered tonight I have a leak around my domestic coil, and the manual isn't specific on that installation. My boiler was used, and had the "patch panel" added in the domestic area, so now, I have 1/2' studs where the new gasket, and domestic plate is installed. My leak is along one of the studs? When I removed the nut, the water sprayed out, at boiler pressure, so I hurriedly rolled an o ring down the stud, smeared some red rtv silicone on, and ran the nut down again. Seems to have stopped that leak, but should there be an o ring on every stud? should I pull the coil and try and figure out why the water came around the interior gasket? I wouldn't expect to have these studs to have made a water tight connection, so somehow the water got to the studs. Looked like a competent welding job, so I don't know where to look next. Other than that issue, I had no big problems other than the grunt work getting it installed. What to do?

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Rob R.
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Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Coal Size/Type: Lehigh Rice
Other Heating: Dad's 1953 EFM Highboy
Location: Chazy, NY

Post Tue. Dec. 07, 2010 8:52 pm

The water has to be leaking by the gasket, or leaking around that stud where it is mounted in the boiler. The second option requires pulling the coil to further investigate, so I would start by checking that your coil mounting nuts are properly tightened...or "snug". I don't know the torque spec, but it doesn't take much effort with a box wrench or rachet. You want to snug things up without tearing the gasket (a little bulge is acceptable).

If everything appears to be tight, and the gasket does not appear to be squished out or torn, the next step is to pull the coil and look things over.

Is the 520 your only source of heat?

leward
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Posts: 42
Joined: Fri. Jul. 03, 2009 2:41 pm
Stove/Furnace Make: EFM 520
Stove/Furnace Model: 1

Post Tue. Dec. 07, 2010 9:36 pm

it is our only heat, so down time has to be at a minimum with these temps. When I installed the coil, the area looked good, I put a thin film of red rtv, new gasket, thin film red rtv and then the coil. Just snugged it up. no problem for 2 months, and now a leak. When I went to try and snug it further, lots of leak, so that was when I mcguyvered it for a quick fix. I can't figure out how the water got around the gasket /rtv film, cause I let it dry for days before water was introduced??

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stoker-man
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Hand Fed Coal Boiler: 1981 efm wcb-24 in use 365 days a year
Coal Size/Type: Anthracite/Chestnut
Other Heating: Hearthstone wood stove
Location: Lehigh Valley, PA

Post Tue. Dec. 07, 2010 10:15 pm

You should not have used any sealant. It probably caused the gasket to creep. Also, if you overtightened the nuts, it probably caused the gasket to tear. I would start with nuts torqued to 10 ft. lbs. If the gasket bulges at the nut more than 1/16", you've gone too far. You can always increase evenly from there.

At this point, I think you have to install a new gasket.

leward
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Posts: 42
Joined: Fri. Jul. 03, 2009 2:41 pm
Stove/Furnace Make: EFM 520
Stove/Furnace Model: 1

Post Tue. Dec. 07, 2010 11:01 pm

no sealant? never would have suspected that. Well, now I know..

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