Boiler Flange, Gasket or sealant?

[m***@yahoo.com]

I have an oil-fired boiler for heating my home. This one is welded
steel. There is a large flange (about 9" in diameter & secured by 6
bolts) where the controls & immersion coil go into the water jacket.
It is currently sealed by the original gasket which is now leaking a
bit. I bought the standard red 1/4" thick gasket matetial with plans
to cut out a new one & replace it, but I have to wonder if there isn't
a better, cheaper way.

Can I simply seal this flange with high-temperature RTV (also known as
Silicone Rubber). The Black stuff is rated for about 600 degrees.
Any thoughts?

Mike N.

[Noon-Air]

Post by m***@yahoo.com
I have an oil-fired boiler for heating my home. This one is welded
steel. There is a large flange (about 9" in diameter & secured by 6
bolts) where the controls & immersion coil go into the water jacket.
It is currently sealed by the original gasket which is now leaking a
bit. I bought the standard red 1/4" thick gasket matetial with plans
to cut out a new one & replace it, but I have to wonder if there isn't
a better, cheaper way.

Do you want it cheap?? or do you want it right??

Post by m***@yahoo.com
Can I simply seal this flange with high-temperature RTV (also known as
Silicone Rubber). The Black stuff is rated for about 600 degrees.
Any thoughts?

Yup, quit while your ahead, call a *competent* tech that has the correct
gasket out of the proper material, and the correct sealer. Have you thought
about what you gonna do if your repair leaves you worse off than when you
started?? wrong gasket?? worse leaks?? broken bolts?? cracked flange??
flange corroded beyond acceptable limits??
FWIW, RTV is not a good thing on *ANY* steam system.

[Tekkie®]

posted for all of us...

Post by m***@yahoo.com
I have an oil-fired boiler for heating my home. This one is welded
steel. There is a large flange (about 9" in diameter & secured by 6
bolts) where the controls & immersion coil go into the water jacket.
It is currently sealed by the original gasket which is now leaking a
bit. I bought the standard red 1/4" thick gasket matetial with plans
to cut out a new one & replace it, but I have to wonder if there isn't
a better, cheaper way.
Can I simply seal this flange with high-temperature RTV (also known as
Silicone Rubber). The Black stuff is rated for about 600 degrees.
Any thoughts?
Mike N.

Call the nice person that services your boiler (if you get it serviced).
This job can be a real pain in the rear to fix and do it now while they are not
backed up stem to stern with service calls and it's not real cold and snowy and
messed up. It might be painful to pry a few bucks from your purse but think of
the satisfaction you will have when you watch the poor person struggle with it
to fix it and you can put wooly socks on your feet propped on the barfolounger
with your loved ones surrounding you with warm tidings of the holiday season
and winter instead of flames and hot spit emanating from both your spouse and
boiler in equal amounts because you patched it with rubber cement.

[m***@yahoo.com]

Gents,

How about some information rather than just lecture..... Is there
something wrong with High-Temp RTV? If so, what it is it that is
wrong? It works in automotive applications at higher temperatures and
similar pressure.

For what it's worth; I have a supply of the "correct" gasket
material. I also see that the same material installed about 10 years
ago in other small flanges on my system, is now rock hard. So, I
suspect the classic material is not ideal either.

Mike

[Noon-Air]

Post by m***@yahoo.com
Gents,
How about some information rather than just lecture..... Is there
something wrong with High-Temp RTV? If so, what it is it that is
wrong? It works in automotive applications at higher temperatures and
similar pressure.
For what it's worth; I have a supply of the "correct" gasket
material. I also see that the same material installed about 10 years
ago in other small flanges on my system, is now rock hard. So, I
suspect the classic material is not ideal either.
Mike

Pardon me Mr Tightwad, but as I said before RTV is *NOT* designed for nor is
it intended for use on a boiler.
Try this
http://www.lawsonproducts.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10001&storeId=10001&productId=53822&catpath=All+Products%2F%2F%2F%2FUserSearch%3DANTISEIZE
The gasket material itself is not supposed to last forever either.

[m***@yahoo.com]

Post by Noon-Air
Pardon me Mr Tightwad, but as I said before RTV is *NOT* designed for nor is
it intended for use on a boiler.

Noon-Air,

I don't particularly care for your derogatory tone or the childish
name calling.

In addition, you appear to be not-very-well-infomed as in the mean
time I found a reference in a Carrier Manual on servicing their cast
boiler. Carrier instructs.... "Reseal seams between adjacent sections
as necessary with 400°F RTV"

Mike

[m***@yahoo.com]

Noon-Air,

One more thing... You had best get in touch with Weil-Mclain also &
let them know that "RTV is *NOT* designed for nor is it intended for
use on a boiler."

It seems they are unaware of this fact. Damn those stupid
manufacturers....They call for & recommend it to seal boiler sections
too. In this case they cal for "RTV silicone sealant (Dow Corning 700
or 732 )"

Mike

[Dowdy167]

replying to Noon-Air, Dowdy167 wrote:
So why does my new Utica boiler have rtv on every seam and cover?

--
for full context, visit https://www.homeownershub.com/hvac/boiler-flange-gasket-or-sealant-29417-.htm

[Tekkie®]

Dowdy167 posted for all of us...

Post by Dowdy167
So why does my new Utica boiler have rtv on every seam and cover?
--
for full context, visit https://www.homeownershub.com/hvac/boiler-flange-gasket-or-sealant-29417-.htm

Uhh Dowdy, I believe Noon-Air has passed away. Get a real newsreader and
find out what is being discussed on the newsgroup: alt.home.repair

[Scott Lurndal]

Post by Tekkie®
Dowdy167 posted for all of us...

Post by Dowdy167
So why does my new Utica boiler have rtv on every seam and cover?
--
for full context, visit https://www.homeownershub.com/hvac/boiler-flange-gasket-or-sealant-29417-.htm

Uhh Dowdy, I believe Noon-Air has passed away. Get a real newsreader and
find out what is being discussed on the newsgroup: alt.home.repair

alt.home.repair is a total cesspool. Avoid if at all possible.

[m***@yahoo.com]

Post by Tekkie®
Dowdy167 posted for all of us...

Post by Dowdy167
So why does my new Utica boiler have rtv on every seam and cover?
--
for full context, visit https://www.homeownershub.com/hvac/boiler-flange-gasket-or-sealant-29417-.htm

Uhh Dowdy, I believe Noon-Air has passed away. Get a real newsreader and
find out what is being discussed on the newsgroup: alt.home.repair
--
Tekkie

People replying to years old thread crack me up. I didn't know Steve has passed. I know Milligan and the Mormon have. Anyone else?

[PaxPerPoten]

Post by m***@yahoo.com

Post by Tekkie®
Dowdy167 posted for all of us...

Post by Dowdy167
So why does my new Utica boiler have rtv on every seam and cover?
--
for full context, visit https://www.homeownershub.com/hvac/boiler-flange-gasket-or-sealant-29417-.htm

Uhh Dowdy, I believe Noon-Air has passed away. Get a real newsreader and
find out what is being discussed on the newsgroup: alt.home.repair
--
Tekkie

People replying to years old thread crack me up. I didn't know Steve has passed. I know Milligan and the Mormon have. Anyone else?

A bunch!

[-zero]

Post by m***@yahoo.com
I have an oil-fired boiler for heating my home. This one is welded
steel. There is a large flange (about 9" in diameter & secured by 6
bolts) where the controls & immersion coil go into the water jacket.
It is currently sealed by the original gasket which is now leaking a
bit. I bought the standard red 1/4" thick gasket matetial with plans
to cut out a new one & replace it, but I have to wonder if there isn't
a better, cheaper way.

No. There's nothing long and painful about replacing a gasket.
Use a Flexitallic if applicable.

Post by m***@yahoo.com
Can I simply seal this flange with high-temperature RTV (also known as
Silicone Rubber). The Black stuff is rated for about 600 degrees.
Any thoughts?

No one will stop you. Why don't you just do it then?
You came here asking, didn't like what
you heard, and are now "telling" how it could be done?
Nice...

It may not leak right away. Does that mean it's fixed? It is not
the correct or acceptable way to repair your leak,
nor is it safe. Considering "how" it will fail as a blow-out
instead of a small leak as gaskets are anticipated to
do, should they fail.

If you called a repair company out, and this is how
they "fixed" your boiler, you would be told how you
got screwed, and the tech should be fired. End of story,
do it right. Don't take this the wrong way, but you do not
appear to be qualified for tackling this particular
repair properly.

-zero

Post by m***@yahoo.com
Mike N.

[m***@yahoo.com]

Actually I got to the bottom of the issue by digging into the
manufacturer's info available (but pretty buried) on the web.

1.) RTV is the recommended material to re-seal boiler sections.
Manufacturers recommend it in locations where the seal is not at a
serviceable location. RTV has longer life & less degradation with
temperature than the gasket material (which is Buna S). But it has
disadvantages too.....

2.) There is a cure time, so the boiler can't be promptly fired up.
In addition, it not easy to take apart later. So it is not ideal for
a seal which has to be broken for service in the future.

In my case, the flange mounts an immersion coil. The coil is meant to
be serviceable, so naturally they use a gasket to allow disassembly.

I don't use the coil any longer, I'm actually going to discard it &
plug the ports.

With the coil discarded, this flange never needs to come off again.
So, I think I'll use the sealant that manufacturers recommend on their
non-serviceable joints (like boiler sections).

Mike

p.s. Thanks for your gracious & professional exchange of information

[Bubba]

Post by m***@yahoo.com
Actually I got to the bottom of the issue by digging into the
manufacturer's info available (but pretty buried) on the web.
1.) RTV is the recommended material to re-seal boiler sections.
Manufacturers recommend it in locations where the seal is not at a
serviceable location. RTV has longer life & less degradation with
temperature than the gasket material (which is Buna S). But it has
disadvantages too.....
2.) There is a cure time, so the boiler can't be promptly fired up.
In addition, it not easy to take apart later. So it is not ideal for
a seal which has to be broken for service in the future.
In my case, the flange mounts an immersion coil. The coil is meant to
be serviceable, so naturally they use a gasket to allow disassembly.
I don't use the coil any longer, I'm actually going to discard it &
plug the ports.
With the coil discarded, this flange never needs to come off again.
So, I think I'll use the sealant that manufacturers recommend on their
non-serviceable joints (like boiler sections).
Mike
p.s. Thanks for your gracious & professional exchange of information

Like most of us in here really thought you were even going to
listen................haaaaaaaa.
Oh, by the way, in a boiler.........never say "Never". Its only a
matter of "when".
Are you an EE?
Bubba

[DIMwit]

Post by m***@yahoo.com
I have an oil-fired boiler for heating my home. This one is welded
steel. There is a large flange (about 9" in diameter & secured by 6
bolts) where the controls & immersion coil go into the water jacket.
It is currently sealed by the original gasket which is now leaking a
bit. I bought the standard red 1/4" thick gasket matetial with plans
to cut out a new one & replace it, but I have to wonder if there isn't
a better, cheaper way.
Can I simply seal this flange with high-temperature RTV (also known as
Silicone Rubber). The Black stuff is rated for about 600 degrees.
Any thoughts?
Mike N.

In addition to everything everybody else said, be prepared to have to drill
out and replace at least one of those bolts that will probably break when
you try to unscrew them to remove the domestic water coil. That's why nooner
referred you to the anti seize product you should use on the new bolts when
you put them in.

This not a fun job and if you are going to do it yourself, this is not the
best time of the year to have your boiler disassembled and unable to put
back together in a timely manner.

On the other hand if you enjoy complete frustration, this will be an
enjoyable job. Piece o' cake.

Make sure you are likkered up when you do this, as it helps you laugh at
yourself.