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Default immersion heater seal

guess my last post wont be read due to the title i gave it, but i really do
have a leaky wet flange.....

the immersion heater flange on the motorhomes calorifier,

old seal was a thin O ring, new seal is a waxed gasket the width of the
entire flange seating area, still leaks, but not as much,

what would be the recomended sealant to use on the flange? i'll avoid boss
white as i might want to take it appart sometime in the future,
i could use silicone sealant, but i'd rather not if something better is
recomended,

there's tru blu, which mentions it's for flange mating surfaces, and it's
recomended for joints subject to vibration, which is the case in a
motorhome.

or would liquid ptfe be better? i'll wrap some ptfe tape around the threads,
even tho i know the seal is the flange it's self, but it seems recomended to
help getting the thing undone at a later date,

Basicaly it'll have to be something i can get from toolstation, as that's
where i'm going tommorow,

they do a washer that looks like it's a fiber type, would one of those be
better? assuming toolstations washers are fibre??

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Default immersion heater seal


"Gazz" wrote in message ...
guess my last post wont be read due to the title i gave it, but i really
do have a leaky wet flange.....

the immersion heater flange on the motorhomes calorifier,

old seal was a thin O ring, new seal is a waxed gasket the width of the
entire flange seating area, still leaks, but not as much,

what would be the recomended sealant to use on the flange? i'll avoid boss
white as i might want to take it appart sometime in the future,
i could use silicone sealant, but i'd rather not if something better is
recomended,


Had the same problem on a domestic immersion tank where the paper gasket
alone simply wouldn't seal it. Maybe the flange was distorted somehow. A
smear of ordinary clear silicone on both sides of the gasket sorted it. Make
sure to let it cure overnight before filling with water again though.
--
Dave Baker


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Default immersion heater seal

On Mar 29, 2:16*am, "Dave Baker" wrote:
"Gazz" wrote in ...
guess my last post wont be read due to the title i gave it, but i really
do have a leaky wet flange.....


the immersion heater flange on the motorhomes calorifier,


old seal was a thin O ring, new seal is a waxed gasket the width of the
entire flange seating area, still leaks, but not as much,


what would be the recomended sealant to use on the flange? i'll avoid boss
white as i might want to take it appart sometime in the future,
i could use silicone sealant, but i'd rather not if something better is
recomended,


Had the same problem on a domestic immersion tank where the paper gasket
alone simply wouldn't seal it. Maybe the flange was distorted somehow. A
smear of ordinary clear silicone on both sides of the gasket sorted it. Make
sure to let it cure overnight before filling with water again though.


That's what I'd reach for. Get the soft stuff and its very easy to cut
or break later. High modulus? I can never remember which is which.


NT
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Default immersion heater seal

On Mar 29, 1:47*am, "Gazz" wrote:
guess my last post wont be read due to the title i gave it, but i really do
have a leaky wet flange.....

the immersion heater flange on the motorhomes calorifier,

old seal was a thin O ring, new seal is a waxed gasket the width of the
entire flange seating area, still leaks, but not as much,

what would be the recomended sealant to use on the flange? i'll avoid boss
white as i might want to take it appart sometime in the future,
i could use silicone sealant, but i'd rather not if something better is
recomended,

there's tru blu, which mentions it's for flange mating surfaces, and it's
recomended for joints subject to vibration, which is the case in a
motorhome.

or would liquid ptfe be better? i'll wrap some ptfe tape around the threads,
even tho i know the seal is the flange it's self, but it seems recomended to
help getting the thing undone at a later date,

Basicaly it'll have to be something i can get from toolstation, as that's
where i'm going tommorow,

they do a washer that looks like it's a fiber type, would one of those be
better? assuming toolstations washers are fibre??


Use Loctite 55 sealing cord:

http://www.screwfix.com/prods/42142/...-Seal-Cord-50m

It's like a thick, heavy, waxy PTFE tape made into a cord (in fact a
bit like a "heavy dental floss").

Has been recommended many times on here, and I've used it to seal an
immersion heater with an 8 metre pressure head. Worked perfectly,
first time.
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Default immersion heater seal

On Tue, 29 Mar 2011 01:47:32 +0100, Gazz wrote:

old seal was a thin O ring, new seal is a waxed gasket the width of the
entire flange seating area, still leaks, but not as much,

what would be the recomended sealant to use on the flange?


Fernox LSX. Silicone will no doubt work but how easy it will be to
break the joint again later is another matter. Getting immersions out
can be a barstweard of a job with just corrosion let alone an
effective glue in the joint...

they do a washer that looks like it's a fiber type, would one of those
be better?


As the thin(?), relatively hard(?), waxed gasket hasn't sealed that
suggests some distorion or damage to the flange, either or both
sides. A thicker, softer, fibre washer will conform better to the
distortion and thus stand more chance of sealing. Fibre washers also
"selfseal" as they expand when they get wet.

--
Cheers
Dave.





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well, none of those suggestion will work, the damn thing was left full of
water over winter, how i dont know as i drain the system down and blow the
pipes thru with compressed air, could have a non return valve stuck i guess
and it backfilled or something, but either way, the damn thing has expanded
and cracked the solder joints.

i can see 3 or 4 cracks in the immersion heater flange solder ring, and it
deffo leaks out of some of them as i scraped the insulation off around
there,
but the whole tank has expanded enough to crack the insulation, and the seam
shows signs of external cracks,

apparantly it's a folded and silver soldered join there,

bod know if it can be fixed, the insulation will need stripping off for
sure, then i guess every fitting and all seams re-soldered, and
re-insulated,

it's about £350 for a new calorifier, which i can not afford anyway, so
looks like im screwed good and proper.

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On Tue, 29 Mar 2011 01:47:32 +0100, Gazz wrote:

they do a washer that looks like it's a fiber type, would one of those
be better? assuming toolstations washers are fibre??


I've no idea how motorhome immersion heater fittings compare with those
on domestic hot water cylinder immersion heaters, but on the latter I use
a *lot* of PTFE tape wound round the thread and built up heavily onto the
shoulder so that, as the heater is tightened, the PTFE adds to the fibre
washer in sealing the face of the heater flange to the flange on the
cylinder boss.


--
John Stumbles -- http://yaph.co.uk

Many hands make light work. Too many cooks spoil the broth.
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"YAPH" wrote in message
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On Tue, 29 Mar 2011 01:47:32 +0100, Gazz wrote:

they do a washer that looks like it's a fiber type, would one of those
be better? assuming toolstations washers are fibre??


I've no idea how motorhome immersion heater fittings compare with those
on domestic hot water cylinder immersion heaters, but on the latter I use
a *lot* of PTFE tape wound round the thread and built up heavily onto the
shoulder so that, as the heater is tightened, the PTFE adds to the fibre
washer in sealing the face of the heater flange to the flange on the
cylinder boss.


same as a home one, it's really a boat item, very few motorhomes use the
type of heating system i have fitted to mine, more usefull if you move the
van every day, as you heat the water for free using the waste engine heat,

it's basicaly a mini hot water cylinder, but an unvented one, however it
seems the copper it a lot thicker than a domestic cylinder, to take the
stresses of being full of water and in a moving vehicle/boat at the same
time as being heated to 85 to 90 degrees C.

But alas the sealing surface wasnt the cause of the leak, a wrap of ptfe
tape around the threads, a new fibre washer and some tru blu sealant (which
seems very much like blue hylomar used on engines) and i had the heater to
flange sealed nicely,

then i was able to find the true source of the leak, cylinder had been left
full of water over winter, frozen, bulged, and cracked the apparantly silver
soldered joins,

as it's a pressure vessle i cant get it repaired and re-certified, so need a
new un, nice start to the season,

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