Re: Quick basic advice on a dripping gas 40-gal hot-water heater

[[email protected]]

Good point. We should remove the anode every year so that it *can* be
removed when it comes time to replace it with a similarly sized one.

One thing we still need to do is attach the drainage pipe from the
Temperature & Pressure valve to near the floor in case of an overflow.http://www.flickr.com/photos/donnaohl/2274211119/

Is the drain pipe mandatory (can we just leave it off)?

It seems to me a drain pipe *should* be mandatory because you don't want
hot water spewing forth at eye level. However, due to configuration
changes, even with the taller tank, the old drainage tube is too long and
too close to the tank so we can't just screw the old one in. We have to
modify it somehow to make it shorter and move it away from the wood base.

QUESTION:
How many inches ABOVE the garage floor should it end?http://farm3.static.flickr.com/2030/2273228265_01c9df0f48_m.jpg

If we can end ABOVE the 18 inch wooden platform, that would be easier.
If we have to end six or so inches above the garage cement floor, that
would necessitate an elbow to get past the wooden base but it seems a
horizontal line can clog causing a safety hazard.

I googled but did not find any specs as to HOW MANY INCHES above either the
floor or better yet, the wooden platform, that a drain pipe must terminate..

Can someone recommend a solution?

Thanks
Donna

new plastic [pipe and fitting will repace the drain line easily.......
no biggie

replace the galvanized all of it before it leaks and causes mold ,
structural damage or a flood.

it will fix all flow issues and make your home more valuable

 

[Donna Ohl, Grady Volunteer Coordinator]

new plastic [pipe and fitting will repace the drain line easily.......
no biggie

This implies we can't use plastic for the discharge tube:
http://www.usinspect.com/WaterHeaters/HWaterTPRVDischargeTube.asp

Here's what it says ... (catch that last counter-intuitive line!)...
Donna

A discharge tube is a tube or pipe that is attached to the TPR valve that
directs the superheated water down to the floor and away from anyone in the
discharge area to prevent scalding or burning.

The pipe itself must be made of a material that is rated for both high
temperature and pressure, which includes most rigid wall copper or iron.
Also, the size of the pipe must match the opening size of the TPR valve
discharge (usually ¾ inch).

The tube must terminate no more than 6 inches from the floor or be directed
to the exterior of the home.

If the discharge tube is routed to the exterior, the pipe must discharge 6
to 24 inches from grade, with a downward slope to prevent the pipe from
clogging or forming a trap. Blocked discharge tubes will prevent the
superheated water from discharging and will burst.

Though counterintuitive, it is often recommended that the discharge tube
terminate next to the water heater so that any malfunction of the water
heater will be more readily noticed.

 

[Donna Ohl, Grady Volunteer Coordinator]

The tube must terminate no more than 6 inches from the floor or be directed

to the exterior of the home.

Notice this one says six to twelve inches above the floor:
http://www.factsfacts.com/MyHomeRepair/PressureRelief.htm

And, again, note the restrictions on the materials.

The discharge tube overflow pipe "must be made of a material that's rated
for both high temperature and pressure. This includes most rigid wall
copper, iron and, in most places, chlorinated polyvinylchloride (CPVC
plastic not regular PVC) pipe. The pipe size must match the opening size
of the TPR valve discharge (usually ¾ inch). It must terminate 6"-12"
above the floor, and the end cannot be threaded or have a fitting which
permits connecting a plug or cap."

 

[Bob M.]

2. Even Superman couldn't would have a tough time removing mine ...
http://farm3.static.flickr.com/2033/2274085498_52c3b7d618.jpg?v=0

Given it took a pipe wrench plus a huge cheater bar to remove the anode
with the water heater removed and blocked on the ground ... and given that

On your new heater, take the anode out and wrap the threads once with teflon
tape or anti-seize compound. Much easier to remove the next time; still
provides protection too.

 

[James Sweet]

On your new heater, take the anode out and wrap the threads once with
teflon tape or anti-seize compound. Much easier to remove the next time;
still provides protection too.

Doesn't it still need to be grounded to the tank?

I remember from boats that the sacrificial anode needs a good solid ground
connection to the engine or transmission block.

 

[[email protected]]

Doesn't it still need to be grounded to the tank?

I remember from boats that the sacrificial anode needs a good solid ground
connection to the engine or transmission block.

yes it does,,,,,,,,,,,, no metal to metal contact no protection.....

geez i just replace the tank when it fails, it gets me a more efficent
unit every 10 years or so.

disturbing the anode and messing with the tank can generate a leak and
early tank replacement.........

 

[Bob M.]

Doesn't it still need to be grounded to the tank?

I remember from boats that the sacrificial anode needs a good solid ground
connection to the engine or transmission block.

Yes, and it is even with a layer of teflon tape. Can be easily tested with
a meter. If someone's really concerned, use anti-seize compound available
at auto parts places. It's used for spark plugs.

 

[Donna Ohl, Grady Volunteer Coordinator]

yes it does,,,,,,,,,,,, no metal to metal contact no protection.....

In addition to the prior quoted article from Rheem which says to use Teflon
tape on the sacrificial anode, these guys on the plumbing forum ran an
experiment by wrapping 20 layers of Teflon tape around a threaded coupling
and then measuring the electrical resistance:
http://www.plbg.com/forum/read.php?1,285316

Here's what they say about it.
Donna

"I just put about 20 layers of teflon tape on each end of a nipple and
tightened one into female galv an one end into female copper. I then used a
multimeter to measure the resistance from one fitting to the other, through
the two teflon-tape joints. The resistance was less than a tenth of an ohm
(i.e. short circuit).

When I did the same across a dielectric union, I got about 2 mega-ohms
(i.e. there's just a tiny bit of conduction through the water, but the
metals aren't touching)

So the business about teflon tape being just as good as a dielectric union
is complete nonsense. The threads just cut through the teflon. It may work
in some cases, but it won't work in others and should not be recommended.

What's amazing to me is that there are all these "old plumbers' tales" out
there, so people are arguing about whether brass or teflon or stainless are
good or bad. Shouldn't this be scientifically determined? I realize that
corrosion happens over many years, but still, there must be ways of
measuring corrosion in the lab. It shouldn't be a matter of opinion or
first-person stories (anecdotal evidence)."

 

[Donna Ohl, Grady Volunteer Coordinator]

Water expands when heated... Older systems allow that pressure to go back into
the supply line towards the street. newer systems have check valves.

Hi Rick,

I was wondering why BOTH the hot water outlet and the cold-water inlet had
check valves built into the respective dialectric nipples provided in the
top of the new tank!

Are you saying the hot-water check valve prevents hot water from leaking up
the pipe for efficiency reasons; while the cold-water check valve prevents
hot water from leaking backward into the supply line?

If the pressure is 150 psi inside the tank, what is the pressure the hot
water is coming out? Is it at 150 psi while the cold water remains at 80
psi? I find that hard to believe, empirically.

Donna

 

[Donna Ohl, Grady Volunteer Coordinator]

Yes, and it is even with a layer of teflon tape. Can be easily tested with
a meter. If someone's really concerned, use anti-seize compound available
at auto parts places. It's used for spark plugs.

I think "grounded" might not be the right word; but the anode must be
"connected" electrically to the tank as a requirement for its purpose.

I do remember in my research last week (oh so long ago) one article where
guys tested it with an ohmmeter and found that Teflon tape didn't hurt the
anodic action.

Here's one article that says distinctly to use Teflon on the anode:
http://www.inspectorsjournal.com/forum/topic.asp?TOPIC_ID=2431

There it says:
"Remove the old anode rod with a 1 and 1/16 inch six-sided wrench or
socket. Do NOT use a 12-point wrench or socket or you will strip the head
of the anode. Get at least a 24-inch cheater bar. I keep a piece of 3/4
inch black iron pipe in the garage just for this purpose. Place the cheater
pipe over the socket handle. Have someone hold the water heater while you
slowly break the seal. Once broken, the anode removes quite easily."

It goes on to talk about the Teflon:
"Replace with a new anode rod. It is a 3/4-inch National Pipe Thread (NPT)
part. You may find one at any plumbing house or home store. Use pipe sealer
or Teflon tape to seal the threads. Snug it down tightly. Remember the
water heater builds up 150 PSI of pressure inside the tank."

BTW, where does the 150 psi come from?
I thought incoming water was about 80 psi.
Does just the fact we're heating the water raise the pressure?
Why? It's only 120 degrees (merely hot); not 212 degrees (boiling).

Does the pressure of the hot water rise to 120 psi while the pressure of
the cold water remains at 80 psi?

 

[Rick Blaine]

BTW, where does the 150 psi come from?
I thought incoming water was about 80 psi.
Does just the fact we're heating the water raise the pressure?
Why? It's only 120 degrees (merely hot); not 212 degrees (boiling).

Does the pressure of the hot water rise to 120 psi while the pressure of
the cold water remains at 80 psi?

Water expands when heated... Older systems allow that pressure to go back into
the supply line towards the street. newer systems have check valves.

 

[Edwin Pawlowski]

If the pressure is 150 psi inside the tank, what is the pressure the hot
water is coming out? Is it at 150 psi while the cold water remains at 80
psi? I find that hard to believe, empirically.

Donna

It is whatever it is until you open a valve and it will be no more than the
cold water behind it. Static pressure is probably not much more than the
dynamic anyway given the low temperature. Water does not compress well so
it is very easy to relieve pressure so there will be no dramatic "poof" when
you open the tap.

If, however, the gas ran wild and made steam you could have much more
pressure and a violent release.

 

[Donna Ohl, Grady Volunteer Coordinator]

I remember from boats that the sacrificial anode needs a good solid ground
connection to the engine or transmission block.

Hi James,

Many articles I find on replacing the sacrificial anode discuss the use of
Teflon tape to prevent leaks. Apparently the threads cut right through the
tape to make plenty of metal to metal contact in the steel tank.

For example, "This Old House"
http://www.thisoldhouse.com/toh/video/0,,20047047,00.html
shows a video of a destroyed sacrificial anode (just like mine) and a
passivated (covered in Calcium deposits) sacrificial anode. They replaced
it with both a three-foot-eight-inch straight anode and a three-link
sausage-shaped collapsible anode (for tight spaces). Both had Teflon tape
in the threads!

In addition, this article was written by a housing specialist and was
reviewed by three PH.D.s and the EPA - and it clearly says to use Teflon
tape on the sacrificial WH anode for replacement:
http://www.fcs.uga.edu/ext/pubs/hace/HACE-E-60-05.pdf
They say:
"Wrap the threads of the new rod in Teflon tape."

This article by John Wood Heaters also says to use Teflon tape:
http://www.johnwoodwaterheaters.com/support/techsupport.html
They say:
"Wrap threads of the anode with plumber¢s tape or use pipe dope approved
for use with potable water, and install the (new) anode into tank and
tighten."

This very informative series of articles are some of the best I've seen
explaining sacrificial anodes for water heaters and other topics.
http://216.250.104.54/default.cfm?PageId=42306
It covers lots of interesting topics, including how to bend anodes to fit
them in tight spaces but unfortunately, it doesn't cover the Teflon issue.

 

[Donna Ohl, Grady Volunteer Coordinator]

How can it be that replacing a drain valve in a full tank leaks not water?

I still feel badly that I didn't replace the plastic drain valve with the
brass ball valve because I was afraid the plastic was not removable (that's
what Sears salespeople said anyway, instilling FUD in my mind).

I was subsequently reading how to replace the plastic drain valve after the
fact and they all seem to say it won't leak if I do so with a full tank.

Huh?

How can removing the drain valve at the bottom of a full water heater not
leak 50 gallons of water?

I already saw, first hand, what happens when that drain valve
http://www.flickr.com/photos/donnaohl/2274079114/
snaps off
http://www.flickr.com/photos/donnaohl/2273262545/
spewing 40 gallons of hot water in my garage
http://www.flickr.com/photos/donnaohl/2273262535/

Can someone clarify this statement from, say:
http://216.250.104.54/default.cfm?PageId=41781 (see excerpt below).

Donna


Maintenance Tip #21 Drain valves
Drain valves usually come when you buy them from a manufacturer. They used
to be brass. You should install a 3/4 ball valve on your water heater.
The plastic ones are prone to leaking. To install a brass ball valve, turn
the gas or electricity off and open a hot tap inside the house. If you
have a cone-shaped valve, unscrew it counterclockwise six turns or so and
pull it out at the same time. Now turn it clockwise while continuing to
pull and it will come out. Wrap Teflon on the nipple that is exposed on
the water heater. Attach the ball valve now. If you have a plastic drain
valve that looks like a hose bib, unscrew it by turning the entire valve
itself.
A little water may come out while you're installing a new valve, but not
much at all. Wear gloves to avoid getting scalded.

 

[Gene S. Berkowitz]

Yes, and it is even with a layer of teflon tape. Can be easily tested with
a meter. If someone's really concerned, use anti-seize compound available
at auto parts places. It's used for spark plugs.

Automotive anti-seize compounds should not be used for potable water
connections, due to the presence of petroleum distillates and metals
such as nickel or molybdenum.

--Gene

 

[Nate Nagel]

How can it be that replacing a drain valve in a full tank leaks not water?

I still feel badly that I didn't replace the plastic drain valve with the
brass ball valve because I was afraid the plastic was not removable (that's
what Sears salespeople said anyway, instilling FUD in my mind).

I was subsequently reading how to replace the plastic drain valve after the
fact and they all seem to say it won't leak if I do so with a full tank.

Huh?

How can removing the drain valve at the bottom of a full water heater not
leak 50 gallons of water?

I already saw, first hand, what happens when that drain valve
http://www.flickr.com/photos/donnaohl/2274079114/
snaps off
http://www.flickr.com/photos/donnaohl/2273262545/
spewing 40 gallons of hot water in my garage
http://www.flickr.com/photos/donnaohl/2273262535/

Can someone clarify this statement from, say:
http://216.250.104.54/default.cfm?PageId=41781 (see excerpt below).

Donna


Maintenance Tip #21 Drain valves
Drain valves usually come when you buy them from a manufacturer. They used
to be brass. You should install a 3/4 ball valve on your water heater.
The plastic ones are prone to leaking. To install a brass ball valve, turn
the gas or electricity off and open a hot tap inside the house. If you
have a cone-shaped valve, unscrew it counterclockwise six turns or so and
pull it out at the same time. Now turn it clockwise while continuing to
pull and it will come out. Wrap Teflon on the nipple that is exposed on
the water heater. Attach the ball valve now. If you have a plastic drain
valve that looks like a hose bib, unscrew it by turning the entire valve
itself.
A little water may come out while you're installing a new valve, but not
much at all. Wear gloves to avoid getting scalded.

Their idea of "a little" water is "about 5-10 gallons." I would drain
the tank prior to replacing. I did just this on two heaters in my
basement last year and I was unable to completely drain them (the WH
drains are lower than any drain in the house) I had a mess to clean up
after each one, and lots of sediment came spewing out too. It was
especially fun as both were so close to the floor (wh's not on stands)
that I had to leave the new valves open while starting the threads.
Assembling the whole mess on the bench and installing the garden hose
cap is highly recommended.

There will be less water coming out than you experienced with your old
tank because of the vacuum of having all the valves in the house shut,
but it'll still come out eventually.

nate

 

[[email protected]]

Donna Ohl, Grady Volunteer Coordinator wrote:










Their idea of "a little" water is "about 5-10 gallons."  I would drain
the tank prior to replacing.  I did just this on two heaters in my
basement last year and I was unable to completely drain them (the WH
drains are lower than any drain in the house) I had a mess to clean up
after each one, and lots of sediment came spewing out too.  It was
especially fun as both were so close to the floor (wh's not on stands)
that I had to leave the new valves open while starting the threads.
Assembling the whole mess on the bench and installing the garden hose
cap is highly recommended.

There will be less water coming out than you experienced with your old
tank because of the vacuum of having all the valves in the house shut,
but it'll still come out eventually.

nate

Also, before draining the tank to remove sediment or to work on it,
it's a good idea to shut the gas off a long time before you're going
to do the work. That way, you can use up most of the hot water in
the tank through normal use, instead of wasting it.

 

[[email protected]]

Donna Ohl, Grady Volunteer Coordinator wrote:










Their idea of "a little" water is "about 5-10 gallons." �I would drain
the tank prior to replacing. �I did just this on two heaters in my
basement last year and I was unable to completely drain them (the WH
drains are lower than any drain in the house) I had a mess to clean up
after each one, and lots of sediment came spewing out too. �It was
especially fun as both were so close to the floor (wh's not on stands)
that I had to leave the new valves open while starting the threads.
Assembling the whole mess on the bench and installing the garden hose
cap is highly recommended.

There will be less water coming out than you experienced with your old
tank because of the vacuum of having all the valves in the house shut,
but it'll still come out eventually.

nate

leave all the faucets OFF while changing valves.

the plastic valves are fine if they get just ONE use, to drain the
tank at end of use.......

 

[Donna Ohl, Grady Volunteer Coordinator]

If you are talking about the galvanized nipples with blue plastic flaps that go
between the heater at the cold/hot ports, those are thermal breaks - not check
valves. They reduce the heat loss from the tank into the pipes when the water is
not being used.

A check valve is significantly larger than a nipple and would typically only be
be found after the main valve and before the heater.

Hi Rick,
Oh. That changes things. I'll check with the literature. We thought the hot
had a heat check valve inside the nipple. It had a black rubber center
which the cold nipple didn't have.

Due to the fact there was little room, and we thought the heat-loss valve
was already there, we didn't put in a flap valve and we used a straight
stainless steel flexible pipe.

If what you say is correct, then we may need to replace the stainless steel
flexible pipe with an S-shaped copper flex tube plus a dialectric union.

One question that still confuses me is the BRASS on the ends of some of the
stainless steel and copper pipes. Can we pub BRASS to galvanized or must we
alwyas use a dialectric union. (I ask because the stainless steel pipe had
brass on the end yet it was advertised for iron to iron).

Donna

 

[Rick Blaine]

I was wondering why BOTH the hot water outlet and the cold-water inlet had
check valves built into the respective dialectric nipples provided in the
top of the new tank!

If you are talking about the galvanized nipples with blue plastic flaps that go
between the heater at the cold/hot ports, those are thermal breaks - not check
valves. They reduce the heat loss from the tank into the pipes when the water is
not being used.

A check valve is significantly larger than a nipple and would typically only be
be found after the main valve and before the heater.