hot water tank leaking

[belledbaby]

Please help! I tested my pressure valve on my hot water tank Fri nite. All worked well, or so it seemed. Went back down to do laundry and there is water all over. The pressure relief valve is leaking at a pretty fair clip. I can't afford a plumber right now, is there something I can do to fix it short of jamming some bubble gum up the tube ?

[ABP]

DO NOT JAM ANYTHING INTO THE T&P VALVE !!
When water is heated it expands, the valve is there to vent the pressures created by heating the water. Try turning down the heat a little, this can be done via the acsess ports (Usually 2) one at the top and one at the bottom. Turn off the breaker that feeds the water heater, next remove the screw(s) that hold the acsess plate on, remove the cover and pull back the insulation, there you will see a screw with numbers around it, insert a screw driver and turn counter clock wise. This will lower the temp. in the tank. Re install the covers and turn the power back on and see what happens. If the leaking stops, then fine, if not, you may need to repeat the process untill it does. If it will not stop, I would suggest replacing the T&P valve. Again, do not install anything to try and stop the water as this can cause the tank to burst, and in worst case scenario, I have seen one that ruptured and went right through a mobile home and destroyed it.

[Phelps]

Is the water heater gas, or electric?... out of curiousity.

[LazyPup]

[red]ABSOLUTELY DO NOT PUT ANYTHING IN THE T&P DISCHARGE LINE TO STOP IT UP[RED/]

Although the likelihood of a thermostat failure causing the water heater to go to full fire, none the less, the potential still exists and the T&P valve is the only safety device that could prevent a potentially explosive condition. If a water heater were to explode it physically expands 1728 times its normal size, which means a 50gallon water heater could potentially expand enough to level an average home. T&P valves are nothing to take lightly. If you have any doubt as to the condition of a T&P valve it should be changed immediately.

The post states that the problem first occured after they lifted the T&P valve for a manual test.

There is nothing here to indicate that there was any working problems with the heater prior to manually lifting the valve therefore we would be safe in assuming that thermal expansion is not the cause of the problem, otherwise it would have been aparent even before the valve was lifted.

During normal operation it is common for minerals and salts in the water to settle in the T&P valve seat area and form a light scale. Quite often when the valves are manually lifted for testing small bits of that scale get caught in the valve seat as the valve attempts to reseal. This is especially true if the manual lift handle is slowly lowered back to the normal position.

In most cases the leak can be stopped by lifting the manual lift handle to the full open position, then release it and allow the valve to snap back into position. You may need to repeat this action two or three times. In this manner the snapping action breaks up the scale and the momentary rush of water through the valve will rinse the valve seat permitting the valve to reseal.

If the valve will not reseal after three or four attempts at snapping the valve in this manner the valve should be replaced.

If you need instructions on how to replace the valve post again and i will post a step by step procedure.

[belledbaby]

I have tried "snapping" the valve several ie: 10-15 times, but it still continues to leak. Is replacing the valve a job that a woman and her son-in law can do w/o managing to either blow up the house or totally ruin the water heater? Are u sure I can't just plug the tube? (just kidding)
This is a gas heater. I surely do appreciate your help!

[LazyPup]

Not to worry,,this is a very easy change out.

Note that the following instructions detail both gas and electric water heaters...I included both types in the event that we may have other people reading this post that have electric water heaters. You should be able to copy and paste these instructions to your word processor, then print them out for a step by step checklist.

Before you begin you should purchase a new Temperature & Pressure Relief Valve and either a roll of Red "Triple Density" teflon tape or a small tube of pipe dope.

NOTE: Almost all water gas and electric water heaters between 30gal and 60gal use the same 3/4" "Watts" Temperature & Pressure Relief Valve. You can find the Watts T&P valves in all hardware, home supply and plumbing supply houses for about $15.

Color coding teflon tape is still a relatively new practice and not all hardware stores carry the Red Triple Density Tape. You should not use the white single density tape because it is only certified for use on pipe threads up to 3/8ID pipe. If you have difficulty finding the red tape, pipe dope will work fine, in fact, I personally prefer to use pipe dope on T&P valves.

For the change out you will need a medium sized pipe wrench. About 14" to 18" overall length will do fine. (Pipe wrenches are fairly expensive, but fortunately they are a very common tool so if you do not have one you should be able to borrow one from a friend, family member or neighbor.)

The Procedure:

1. Turn off the water heater "Cold water" supply valve which is located just above the heater on the cold water input line.

2. If this is an electric water heater locate the electric service disconnect switch and turn it off or turn off the circuit breaker for the water heater.

3. If this is a gas water heater locate the gas shutoff valve on the gas line to the heater control. Turn the gas valve "Off"

4. Next you will need to drain the water heater at least to a level below the T&P valve location. Although the T&P valve is located on the top of an electric water heater it must be remembered that there is hot water in the distribution lines above the heater so it is necessary to drain the heater to prevent that water from backflowing and scalding you during the change out.

If the water heater is located in a basement or crawlspace with a floor drain you can open the water heater drain valve and let it drain on the floor. If the heater is in a utility room or a finished basement you should attach a garden hose to the drain valve and run the hose outdoors or to a floor drain before opening the valve.

5. Open a "Hot Water Faucett" at a high point in your water distribution system. Usually the bathroom lavatory faucett will be the best. This will permit air to vent into the hot water system as the water drains, which will aid in expediting the draining process.

6. Locate the T&P valve discharge line and unscrew it from the T&P valve discharge port. Set the line aside so you can install it in the new valve later.

7. If you are using teflon tape wrap 3 full turns of the tape around the threads under tension in the direction of the thread turn. (Clockwise when facing the open end of the threaded pipe)

8. If you are using pipe dope apply a liberal layer of the dope completly around the threads.

9. By this time the tank should be drained down enough that you can remove the existing valve. Using the pipe wrench turn the valve counter-clockwise to unscrew it from the water heater tank. As soon as it is loose you should be able to finish unscrewing it by hand pressure and when the threads are free pull the valve straight out. You will see a short probe attached to the valve which will come out with the valve.

10. Use a rag to clean any debris that may be in the tank mount threads, then insert the new T&P valve and screw it in as far as you can by hand. You will now need to use the pipe wrench to turn the valve another couple turns until it feels tight. Make sure that you turn the valve until the discharge port is pointing down.

11. Now close the tank drain valve and open the cold water supply valve to begin refilling the tank. While the tank is refilling you should watch the flow at the open faucett. Expect a lot of air hissing and perhaps some water sputtering as the tank fills and displaces the air in it. As soon as you have a full flow of water at the faucett you may close the faucett. You should then chech all hot water faucetts in the house to be sure you vent out any excess air in the pipes.

12. The tank is now refilled so you should visually check the new T&P valve thread mount to be sure it is not leaking. If you see any evidence of leaks use the pipe wrench and give the valve one more complete turn, again making sure the T&P discharge port is pointing down.

13. Apply teflon tape or pipe dope to the T&P discharge pipe and screw it into the T&P discharge port. This fitting does not need to be excessively tight.

14. For an electric water heater you may now Reset the electrical breaker or service disconnect.

15. For a Gas Water heater turn the burner control knob to the OFF position, then open the gas valve and follow the manufacturers instructions to relight the pilot light.

At this point you have completed the change out.

[belledbaby]

Thank you so very much for your information! It is a refreshing change to find a place where people help each other. Keep up the good work and God Bless!

[LazyPup]

we hope you will make Homerepairforum your one stop shopping center for DIY information,,,come back often and bring your friends

[Phelps]

LazyPup,

WHAT expands 1728 times it's size? We know the size of the water heater itelf can't stretch that much. We also know the water can't compress at all, let alone 1728 times. Did you maybe mean to say that the pressure exerted in pounds can reach 1728 times the 50 psi, perhaps? I'm just curious on this one.

I have heard of water heaters launching out of a house right through the roof already. But if that doesn't happen, can a water heater explode latteraly and literally level an entire house, as if a bomb went off?

[LazyPup]

Although it is nearly impossible to create the necessary conditions in a water heater, none the less, if the water in the heater were to be heated sufficiently to expand it to steam, the physical expansion of water to steam is 1 x 12 to the 3rd power.

12 x 12 x 12 = 1728 or to put it in simple terms when liquid water flashes to steam, one cubic inch of liquid water produces one cubic foot of gasseous water (steam), which would obviously rupture the vessel and cause serious havoc to the structure.

[belledbaby]

Now it's the drain valve...

I know that as soon as I open the drain valve in the heater to replace the T&P valve, that the drain valve will leak due to minerals etc, it has happened in the past when I flushed some water from bottom of tank. Took forever for me to get it tightened enough to stop dripping. I know I won't be that lucky again. Is this a repair I could handle also?

[LazyPup]

The drain valves on water heaters are 3/4" male thread boiler cocks. The valve has a male pipe thread that screws into a female thread mount in the same manner that the T&P valve does.

Most water heaters come with a cheap plastic drain valve. I often switch that to a brass boiler cock when I install a water heater. Just be sure to apply teflon tape or pipe dope to the male threads and screw the new valve in.