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View Full Version : Water Heater Cold Water Inlet "Overflow"



Rod
12-27-2008, 08:06 PM
Location: Spring Lake, NC

Water Heater: Electric, Bradford White

Model #: M250S6DS2

Concern: Cold Water Inlet "Overflow" Is Active

*SEE PHOTOS

Hello, my name is Rod. Thank you for taking the time to assist me. Please forgive my ignorance of water heater know-how. This is precisely why I request your assistance. (smile) Firstly, I do not know if what I refer to as the "overflow" is indeed an overflow. But, it is definitely attached to the cold water inlet. I recently had my water heater wrapped and noticed some water underneath it yesterday. Not a lot of standing water, but enough to tap your finger against it and make a small 'splash'. You can see in the photo the area beneath the drain valve I had wiped dry. I unwrapped the unit and proceeded to trouble shoot- the drain valve was dry, as well as the TPRV discharge tube. But I did notice moisture coming from a 1/2" PVC tube connected to the cold water inlet.

This is what I refer to as an overflow, if that is correct. I wiped the area dry and directed the PVC tube into a bucket. I checked the bucket 24 hours later (today), and it had about an inch of water in it. The area around the base of my water heater was dry. So, the water heater itself is not leaking.
Of course, the water came from the PVC tube attached to the cold water inlet.

If this is an overflow, please enlighten me on how it is activated, and how often this should occur.

If it is not an overflow PVC tube, please educate me on its purpose along with anything I should be concerned about.

Thank you for your time.
-Rod



http://img.photobucket.com/albums/v370/bic4jesus/WH1.jpg

http://img.photobucket.com/albums/v370/bic4jesus/WH3.jpg

http://img.photobucket.com/albums/v370/bic4jesus/WH2.jpg

http://img.photobucket.com/albums/v370/bic4jesus/WH5.jpg

Probedude
12-27-2008, 08:29 PM
Remove the insulation where that pvc pipe attaches so we can have a better look.

- it's not an overflow but maybe there's a valve under there for an ice maker or RO unit that is no longer installed.

Rod
12-27-2008, 09:02 PM
Remove the insulation where that pvc pipe attaches so we can have a better look.

- it's not an overflow but maybe there's a valve under there for an ice maker or RO unit that is no longer installed.

What's an RO unit do?

Hopefully these will help for you to explain my problem. BTW, I purchased my home new in 2005. There have not been any mods to the unit since then.

This tube should not be leaking, huh? A course of action is appreciated.

Thank you!
-Rod

http://img.photobucket.com/albums/v370/bic4jesus/WH8.jpg

http://img.photobucket.com/albums/v370/bic4jesus/WH7.jpg

http://img.photobucket.com/albums/v370/bic4jesus/WH6.jpg

SewerRatz
12-27-2008, 09:16 PM
ok I have to say this is the first time I seen a valve like that. At first I was thinking it was a stop and waste. But if it where a waste drain off wouldn't water come out of that constantly like full flow. I hope the other guys can enlighten this young Chicago boy on that valve.

Rod
12-27-2008, 09:31 PM
ok I have to say this is the first time I seen a valve like that. At first I was thinking it was a stop and waste. But if it where a waste drain off wouldn't water come out of that constantly like full flow. I hope the other guys can enlighten this young Chicago boy on that valve.

I never paid much attention to it before. But upon closer examination I thought it was odd too. Especially since I was thinking it was an overflow.
But then I thought, "Why would there be an overflow on the cold water inlet?". But of course, I'm not up on water heaters so I brought my question here.

Now I'm wondering... did the plumber do a sloppy job by using the wrong cold water shut-off valve.? One that has an extra valve, and he decided to run a PVC pipe from it?

Then my next question would be, "Why didn't the inspector catch this?".

Perhaps I'm jumping to conclusions...

Verdeboy
12-27-2008, 09:35 PM
My only guess is that the mystery line goes to a non-existent expansion tank.

Rod
12-27-2008, 09:36 PM
BTW, I did run my shower HOT to see if any water would drain from the PVC and into the bucket once cold water came in to replace the outgoing hot.

Nothing happend while the shower was running. Nor did anything happen within 5 minutes of shutting the shower off.

But when I checked it about an hour later, there was a little water in the bucket.

So, how long does it take for cold water to replace outgoing hot? How long before the cold water flows into the water heater?

This is what I was trying to figure out while I was trouble shooting it.

SewerRatz
12-27-2008, 09:39 PM
BTW, I did run my shower HOT to see if any water would drain from the PVC and into the bucket once cold water came in to replace the outgoing hot.

Nothing happend while the shower was running. Nor did anything happen within 5 minutes of shutting the shower off.

But when I checked it about an hour later, there was a little water in the bucket.

So, how long does it take for cold water to replace outgoing hot? How long before the cold water flows into the water heater?

This is what I was trying to figure out while I was trouble shooting it.
See what happens when you turn off the ball valve. I am just curious.

Verdeboy
12-27-2008, 09:40 PM
Cold water fills the tank instantly, as hot water is used.
Good idea, Ratz. I love experiments. :)

Rod
12-27-2008, 09:41 PM
My only guess is that the mystery line goes to a non-existent expansion tank.

If that's it then my valve is upside down, huh?:D

Rod
12-27-2008, 09:44 PM
BTW, if it is for an expansion tank shouldn't the plumber have 'capped off' the valve since there is no tank?

SewerRatz
12-27-2008, 09:46 PM
BTW, if it is for an expansion tank shouldn't the plumber have 'capped off' the valve since there is no tank?

If it where for a tank, water should be flowing out of it nonstop. Otherwise it is useless.

Verdeboy
12-27-2008, 09:46 PM
If that's it then my valve is upside down, huh?:D

It also means the installer never came back from that long lunch to finish the job. But that's only a guess. That valve may be for something else.

Rod
12-27-2008, 09:50 PM
See what happens when you turn off the ball valve. I am just curious.

I turned off the cold water inlet (if that's what you meant) and nothing happened.

The tube definitely expells water when hot water is used. It seems like about an inch or so a day in my bucket. I hate the thought of wasting that water. That can add up over time.

Rod
12-27-2008, 09:52 PM
If it where for a tank, water should be flowing out of it nonstop. Otherwise it is useless.

Hummm... what other purpose could it serve?

Verdeboy
12-27-2008, 10:12 PM
In my research, the only 3-way ball valve I could find with a plastic tube coming down is for winterizing hot water tanks in RV's. The tube somehow sucks antifreeze into the tank from a bucket. But my guess is, you don't live in an RV. :)

Dunbar Plumbing
12-27-2008, 11:01 PM
WTF is going on in here?!?!?!?!


That's a Watts Thermal expansion Ball Valve Shutoff.


It's dumps water when thermal expansion is present, or is malfunctioning which could easily be the case.



Hard pipe copper out of that tank on the cold side, tee off and install a thermal expansion tank and get rid of that valve, install a normal ball valve.


Then reconnect back to that PEX.

Before you do any of this, check your static water pressure at a hose bibb and determine what the pressure is incoming.


If it is above 60, near 80, you got other problems as well.

An expansion tank will provide protection to as little as 1/2 pound of deflection on the bladder, that cannot be achieved with that valve, which is not good at all for the life and longevity of your plumbing system.

MACPLUMB 777
12-28-2008, 01:00 AM
Just what rugged said,
this is a thermal expansion valve
have a plumber replace with a thermal expansion tank

nhmaster
12-28-2008, 04:02 AM
My only guess is that the installer was too cheap to install a ST5 expansion tank and use an expansion valve instead. I think I would remove the valve and install a standard ball valve along with a 3/4" female tee and an expansion tank instead.

Cass
12-28-2008, 04:39 AM
It will look something like this only it will be supported...this one is not...a simple strap would work...

http://bgehome.com/images/pic_wh_extank.jpg

SewerRatz
12-28-2008, 07:17 AM
Rugged Thanks for the heads up on what that valve is. Like I said its the very first time I ever seen anything like that.In all the years and the 1000's of water heaters I replaced, never never seen that valve. Expansion tanks are required on all water heater installs in Illinois, before they only required it if there was a check valve on the inlet or if there was a backflow preventer at the meter.

jimbo
12-28-2008, 07:35 AM
Thanks, Rugged. Never came across that before. Here it is:

http://www.watts.com/pdf/ES-BRV.pdf

We do use a lot of these out here: http://www.watts.com/pdf/es-210-5.pdf

Rod
12-28-2008, 07:44 AM
WTF is going on in here?!?!?!?!


That's a Watts Thermal expansion Ball Valve Shutoff.


It's dumps water when thermal expansion is present, or is malfunctioning which could easily be the case.



Hard pipe copper out of that tank on the cold side, tee off and install a thermal expansion tank and get rid of that valve, install a normal ball valve.


Then reconnect back to that PEX.

Before you do any of this, check your static water pressure at a hose bibb and determine what the pressure is incoming.


If it is above 60, near 80, you got other problems as well.

An expansion tank will provide protection to as little as 1/2 pound of deflection on the bladder, that cannot be achieved with that valve, which is not good at all for the life and longevity of your plumbing system.

Thank you.

I guess I'm confused as to why I would need a relief valve for thermal expansion on the cold water inlet if that's what the T&P Relief Valve is for...
if I correctly understand the function of the T&P Reief Valve.

The temperature this past week has ranged from high 20s to high 60s.

Please answer these questions-

- If thermal expansion is present... isn't that what the T&P Relief Valve is for?

- The water heater is in my garage. Could I have "overwraped" an already insulated water heater? Could this be the cause of my problem? Or, is there no such thing as over insulating a water heater?

- Can I simply forego the expansion tank and have a plumber install a normal valve?

Thank you for your time.
-Rod

Rod
12-28-2008, 08:10 AM
Trying to educate myself here:

http://www.co.union.nc.us/Portals/0/PublicWorks/Documents/WaterPressure/Thermal%20Expansion.pdf

Is my assumption correct in that it is a necessity to have a thermal expansion tank in conjunction with the T&P Relief valve since the expansion tank is designed to release excess pressure under normal water heater operations?

Thank you.
-Rod

SewerRatz
12-28-2008, 08:14 AM
Thank you.

I guess I'm confused as to why I would need a relief valve for thermal expansion on the cold water inlet if that's what the T&P Relief Valve is for...
if I correctly understand the function of the T&P Reief Valve.

The temperature this past week has ranged from high 20s to high 60s.

Please answer these questions-

- If thermal expansion is present... isn't that what the T&P Relief Valve is for?

- The water heater is in my garage. Could I have "overwraped" an already insulated water heater? Could this be the cause of my problem? Or, is there no such thing as over insulating a water heater?

- Can I simply forego the expansion tank and have a plumber install a normal valve?

Thank you for your time.
-Rod

The T&P valve is there as an emergency relief valve. The expansion tank is there to absorb the thermal expansion to prevent the T&P from tripping. I have had many service calls where people said they noticed water dripping from the tube on the T&P. First thing I check for is any sort of backflow preventer, then water pressure. In most cases the city or village changed out meters and meter yokes and the new yokes had built in double checks. With this change the thermal expansion had no where to go so the T&P valve kept opening up just enough to be a problem.

Rod
12-28-2008, 08:15 AM
Trying to educate myself here:

http://www.co.union.nc.us/Portals/0/PublicWorks/Documents/WaterPressure/Thermal%20Expansion.pdf

Is my assumption correct in that it is a necessity to have a thermal expansion tank in conjunction with the T&P Relief valve since the expansion tank is designed to release excess pressure under normal water heater operations?

Thank you.
-Rod

I guess I should really look into North Carolina's plumbing code, heh?

jar546
12-28-2008, 08:23 AM
Are my eyes in need of calibration or does the TPR discharge tube appear to be reduced in size below 3/4".

Where is the pan while we are at it?

jar546
12-28-2008, 08:24 AM
Also,
The first photos show a WH in a finished space. The bottom photo shows the WH on concrete with masonry walls behind it. Did I miss something?

kingsotall
12-28-2008, 08:39 AM
jar, I... I... :confused:

Rod
12-28-2008, 08:50 AM
Are my eyes in need of calibration or does the TPR discharge tube appear to be reduced in size below 3/4".

Where is the pan while we are at it?

Thank you for your input.

I have a book on-hand- Taunton's For Pros By Pros seires, "Inspecting A House", by Rex Cauldwell. It states on pg 158-


"If the T&P valve does ever kick off, you don't want it to drip or spray scalding water all over the tank or in anyone's face. Therefore the valve needs to have a pipe extending from the T&P female threads down to a few inches above the floor. This pipe must not be reduced in size from the female thread size in the valve, which is normally 3/4". Almost any pipe will do-even plastic CPVC- but the pipe cannot be threaded on its bottom end."

I looked at the discharge tube pipe. It reads, "CPVC 4120", "100 PSI at 180F".

There is no pan. I don't know yet if NC code requires one.

Thank you.
-Rod

Rod
12-28-2008, 08:51 AM
Also,
The first photos show a WH in a finished space. The bottom photo shows the WH on concrete with masonry walls behind it. Did I miss something?

The WH is in my garage. The garage walls are finished.

Thank you.
-Rod

Rod
12-28-2008, 09:05 AM
Thank you for your input.

I have a book on-hand- Taunton's For Pros By Pros seires, "Inspecting A House", by Rex Cauldwell. It states on pg 158-



I looked at the discharge tube pipe. It reads, "CPVC 4120", "100 PSI at 180F".

There is no pan. I don't know yet if NC code requires one.

Thank you.
-Rod

This is also on the CPVC discharge tube:

FlowGuard Gold

D2846

jar546
12-28-2008, 09:21 AM
Great information but we need to know the size of the discharge tube. Just make sure it is at lease 3/4".

You have 2 hot water heaters in the photos, one of them is in the garage?

Rod
12-28-2008, 10:48 AM
Great information but we need to know the size of the discharge tube. Just make sure it is at lease 3/4".

You have 2 hot water heaters in the photos, one of them is in the garage?

All of the photos are of the same WH- in the garage. It is the only WH I have.

What's an accurate method to measure it? I thought it would be plainly written on the CPVC pipe.

Also, are you able to answer these?

- The water heater is in my garage. Could I have "overwraped" an already insulated water heater? Could this be the cause of my problem? Or, is there no such thing as over insulating a water heater?

- Can I simply forego the expansion tank and have a plumber install a normal valve?

Thank you.
-Rod

Rod
12-28-2008, 01:33 PM
I want to thank everyone for their advice. I spoke in-debth with MACPLUMB 777 about the need for attaching a thermal expansion tank.

Again, thank you kindly for your time and advice.
-Rod

jimbo
12-28-2008, 02:40 PM
Sounds like you have it all worked out....but just in case: The T/P is a safety to prevent a catastrophic event if the Pressure exceeds the design max limit of the WH ( 150 PSI). But we do not want the house piping to regularly see pressures less than 150, but far exceeding the normal max limit of 80 PSI. That situation is caused by thermal expansion, and is accomodated by a thermal expansion tank, or your thermal relief valve.

kingsotall
12-28-2008, 05:34 PM
I think "jar" still needs closure as to why the posted photos seem to negate each other. :rolleyes:

Probedude
12-28-2008, 06:33 PM
edit; nevermind.