How do I install a Temperature Pressure Release (TPR) valve on my water heater and meet California Code requirements? My gas water heater is over 40 years old and does not have a TPR valve. The only outlets on the water heater are the inlet cold water and outlet hot water pipes on top of the water heater. There is no fitting on the side of the water heater. The water heater works fine and there is no leaking.

Unless California Plumbing Code has some odd requirement that existing water heaters must be retrofitted with a TPR valve, there is no need nor reason to add one now.

Your heater was installed to Code as it existed 40 years ago and as such would be 'grandfathered' and allowed to continue in use as it is.

Could we see a picture of your water heater. I don't think I have ever seen a heater without a T&P valve.

Hi John...

If you chase the cold water line back for a distance back from the water heater can you find anything that resembles a valve of any kind? You should be able to find a shutoff valve and perhaps you'll find an old fashioned type T&P valve... similar to a tankless coil relief valve on a boiler? Take a look... should find one.

ALL water heaters, since the beginning of time have required a relief valve of some kind, so at a minimum you should be able to find a tapping on the side or top of the heater to accept one. If no tapping present then I want to know more about the tank..? Are you sure this isn't a storage tank with a direct or indirect coil for heating the water? If so, then the T&P valve will be associated more so with the coil then with the tank... perhaps?

In my opinion, you've been lucky all these years and have not had any issues, but as that water heater gets older it only gets closer to failing and that failure could result in a dangerous situation so I would recommend that you install some kind of T&P valve in the heater or in the cold water piping into the heater.

Check out what can happen to a simple 12 gallon electric water heater if the system safety devices fail:

http://waterheaterblast.com/

Or click here for a version you don't have to download: http://www.youtube.com/watch?v=GF_Wrm-Ns0I

Finally, we have a great plumber out of California (Milo Dolezal), maybe he'll pop in and present his thoughts.

Any questions... let us know.

Mark

Harold, I was writing as you were. I completely agree!

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"ALL water heaters, since the beginning of time have required a relief valve of some kind, so at a minimum you should be able to find a tapping on the side or top of the heater to accept one. "

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Oh yeah?

I can see you didn't grow up with a coal stove in your kitchen and a water boiler attached to it for domestic hot water production... :)

No pressure relief devices on any of those tanks!

That was in the early 1950s through 1970s and worked something like this:

http://etc.usf.edu/clipart/63400/634..._heater_lg.gif

http://www.inspectapedia.com/plumbin...Coal-030DF.jpg

You didn't run the coal stove in the summer so we only took cold baths.

Still run into the occaisional coal stoker with a hot water boiler tank with no TPR valves that are still in service in my region...

But I've been told I'm older than time, so I guess I predate most TPR valves anyhow... lol

You can post a pic directly using "go advanced/manage attachments".

If not a TPR, is there a rupture disc somewhere? Probably not.

Depending on the fitting (male or female NPT), I hope you should be able to add a TPR using a T fitting.

Either female-female-female or an odd fitting that's Male-female-female. Insert the TPR through the T and take the output of the water heater through the side port of the T.

Use either the weird fitting or a standard T so you don't have to use a nipple. I think the weird fittings are available, just not sure where.


This is the fitting idea I had: 3/4 FORGED STREET TEE - 127F-Street Tee by FittingConnection

I echo Mark's comment: every pressurized tank has to have pressure relieve valve.

I am sure there is a inlet for PRV. It may be plugged as some installers plug it to safe few bucks. It can be either on top of the heater or on its side. If there isn't any plug than put 3/4" brass "T" on existing hot water nipple /outlet, install PRV to its side and reconnect hot water supply line on top of this T. That will satisfy the Code requirements. ( I think this is what KISS tried to suggest... )

The supply side would not make as much sense as the outlet side especially if the heater had a dip tube. This one probably doesn't, but I'd still put it on the outlet side.

This was exactly what I was suggesting. Use the Tee or special T such that the temperature sensor has the most penetration into the tank.

The top of the tank is preferable in any event.

This is what a Dip Tube looks like. The tube itself is attached to the bottom of the nipple and extends to the bottom of the heater... See the pic...

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Originally Posted by manhattan42

Unless California Plumbing Code has some odd requirement that existing water heaters must be retrofitted with a TPR valve, there is no need nor reason to add one now.

Your heater was installed to Code as it existed 40 years ago and as such would be 'grandfathered' and allowed to continue in use as it is.

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You may be correct that I can fight this as grandfather case, but there actually appears to be a safety issue involved and I want to take care of the safety issue without buying a new water heater and do it per code. Thanks John

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Originally Posted by hkstroud

Could we see a picture of your water heater. I don't think I have ever seen a heater without a T&P valve.

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Harold, I am attaching three photos, and have reduced the quality so they they transmit faster; let me know if you can not see something. You will see that the cold and hot piping connections are sound. Also, on top, there is a cap labeled ECO which covers wires going to a part on top of the water heater. Montgomery Ward is the maker of the water heater. Thanks, John

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Originally Posted by massplumber2008

Hi John....

If you chase the cold water line back for a distance back from the water heater can you find anything that resembles a valve of any kind? You should be able to find a shutoff valve and perhaps you'll find an old fashioned type T&P valve...similar to a tankless coil relief valve on a boiler? Take a look...should find one.

ALL water heaters, since the beginning of time have required a relief valve of some kind, so at a minimum you should be able to find a tapping on the side or top of the heater to accept one. If no tapping present then I want to know more about the tank...?? Are you sure this isn't a storage tank with a direct or indirect coil for heating the water? If so, then the T&P valve will be associated moreso with the coil then with the tank...perhaps?

In my opinion, you've been lucky all these years and have not had any issues, but as that water heater gets older it only gets closer to failing and that failure could result in a dangerous situation so I would recommend that you install some kind of T&P valve in the heater or in the cold water piping into the heater.

Check out what can happen to a simple 12 gallon electric water heater if the system safety devices fail:

Water Heater Blast!

Or click here for a version you don't have to download: YouTube - Water Heater Blast

Finally, we have a great plumber out of California (Milo Dolezal), maybe he'll pop in and present his thoughts.

Any questions...let us know.

Mark

Harold, I was writing as you were. I completely agree!

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Mark, please see the photos in my reply to Harold. Also, I checked the side of the water heater by removing the blanket and found no plugs. You are right that I am lucky that the water heater has lasted so many years. And, I am interested in the safety of the water heater. Thanks, John

The PRV port does not have to be on the top of the heater. In many cases it's on the right hand side near the top.

The most likely spot is on the right hand side under the insulating blanket and above the top strap shown in the picture. It would likely be located slightly behind the center line of the inlet pipes.

Idealy, the system should have a dialectric union (prevents corrosion) between the copper and the galvanized, but I would not change it now. A long life indicates that your water contains few ions which is a good thing.

The black port on this heater: http://www.hotwater.com/mediabank/me...-gas/Effex.jpg is the TPR. That's a common height.

For now, just feel with your hands for a plug (bump) along that side near the top. It could be a flush plug, so if you don't find it, you'll have to remove the insulating blanket.

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Originally Posted by KeepItSimpleStupid

You can post a pic directly using "go advanced/manage attachments".

If not a TPR, is there a rupture disc somewhere? Probably not.

Depending on the fitting (male or female NPT), I hope you should be able to add a TPR using a T fitting.

Either female-female-female or an odd fitting that's Male-female-female. Insert the TPR through the T and take the output of the water heater through the side port of the T.

Use either the wierd fitting or a standard T so you don't have to use a nipple. I think the wierd fittings are available, just not sure where.

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KeepItSimple, your idea is the same as my local hardware store recommended but he was not sure it would pass California code. I do not want to mess with the fittings on the hot water pipe unless I am sure that it is the way to go. I am afraid of messing up the old connection which is now sound. Thanks, John

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Originally Posted by Milo Dolezal

I echo Mark's comment: every pressurized tank has to have pressure relieve valve.

I am sure there is a inlet for PRV. It may be plugged as some installers plug it to safe few bucks. It can be either on top of the heater or on its side. If there isn't any plug than put 3/4" brass "T" on existing hot water nipple /outlet, install PRV to its side and reconnect hot water supply line on top of this T. That will satisfy the Code requirements. ( I think this is what KISS tried to suggest...)

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Milo, Why do you recommend a brass T as opposed to a galvanized one as is the piping connection (please see my photos to Harold's reply)? Thanks, John

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Originally Posted by Milo Dolezal

This is what Dip Tube looks like. It is attached to the bottom of the nipple...See the pic...

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Milo, I am not sure what this Dip Tube does. Does the white part extend into the water heater? Please see the photos I attached to Harold's reply. Thanks, John

1. Unwrap the thermal blanket. I bet you there will be plugged inlet that should have been used for T&P relieve valve.

2. That aluminum gas connecting tubing is against the Code. Replace it with new type gas flex connector to bring it up to Code.

3. You should use brass fitting between two dissimilar metals to prevent electrolysis.

4. The earthquake strap you show in your photos is no approved strap. You can buy approved strap in Home Depot or Lowe's. The stamp of approval is on the box.

5. The vent pieces should be secured with 3 sheet metal screws on each joint. No duct tape, please...

1. Check for a port under the blanket. Bet dollars to donuts it's there.

2. When two dissimilar metals are together with an electrolyte (dirty water) it creates a battery and corrodes. See: http://www.hammerzone.com/archives/p...n_de/intro.htm

3. Galvanized fittings rust from the inside. That's not something you want to happen. Brass won't corrode. Well, it does but creates a protective layer like aluminum. Besides galvanized for water just isn't used anymore. The sacrificial anode also limits corrosion. Won't get into details.

4. DIP tube et. al. HowStuffWorks "How Water Heaters Work"

The hot water leaves from the top of the tank. If I dumped cold water in the top, it would layer and make the top layer of water colder.

If we inject water at the bottom of the tank, the top of the tank where the hot water comes out won't cool much, hence you get more hot water.

Still will bet dollars to donuts that the pressure relief port is on the side of the tank near the top.

Milo:

Do you think the flue elbow is backwards too?

The Gas cock is outdated too. That style develops leaks.

Picky compared to the lack of a TPR.

Quote:

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Originally Posted by Milo Dolezal

1. Unwrap the thermal blanket. I bet you there will be plugged inlet that should have been used for T&P relieve valve.

2. That aluminum gas connecting tubing is against the Code. Replace it with new type gas flex connector to bring it up to Code.

3. You should use brass fitting between two dissimilar metals to prevent electrolysis.

4. The earthquake strap you show in your photos is no approved strap. You can buy approved strap in Home Depot or Lowe's. The stamp of approval is on the box.

5. The vent pieces should be secured with 3 sheet metal screws on each joint. No duct tape, please...

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Milo,

1. I have unwraped the thermal blanket at the suggestion of a city building inspector, and there is no plug

2. The photo is prior to me changing out to a flexible gas line

3. The brass T is a good suggestion

4. The earthquake straps actually are the type recommended by the city diagrams. The one you recommend would have been easier to install

5. You are correct, the vent pieces could use screws

Thanks, John