Water Dripping From Water Heater Pipe

[SandraR]

We have had this water heater since at least 2000 and today I noticed about a 3" puddle of water beneath the long copper pipe (see photographs). What is the purpose of that pipe and why every once in awhile a drop of water will drip from it. Again, have never seen this in the last 16 years or so.

Thank you!

Sandra

 

[Reach4]

Purpose is to let water out if the pressure gets dangerously high or the temperature gets excessive.

Do you have a thermal expansion tank? If not, you may need one. If you have one, it may be undersized or may have failed.

Supposedly these things are to be tested regularly, perhaps once per year, by lifting that lever. The water should come out, and stop coming out when the lever is released. If the water does not stop, turn off the water to the WH and the fuel to the WH until you get the T+P valve replaced. If it were to stick open when you were not there to shut things down, you could flood your basement etc.

 

[Sponsor]

 

[Jadnashua]

That has been dripping for a long time as evidenced by the corrosion deposits on it. The pipe is attached to the T&P (temperature and pressure) safety valve. That valve is designed to open if the pressure gets too high, or the temperature gets too high in the tank. If you have a closed system, it can be a symptom of a failed expansion tank, which will cause the pressure to peak when the WH is running to reheat the water. If you open the valve to test, on an old one with corrosion on the stem, it may no longer seal.

 

[SandraR]

Thanks to all who responded. I'll have this valve replaced. That said, is there a danger of the pressure building up to the point such that the tank would explode?

 

[Reach4]

Thanks to all who responded. I'll have this valve replaced.

I wouldn't count on that helping. Did you follow the expansion tank bit? Do you have one? A pressure gauge could be used for troubleshooting to see if the pressure rises to over 100 PSI after you use much hot water. If the pressure gets to 150, your new T+P valve will open too.

 

[SandraR]

I wouldn't count on that helping. Did you follow the expansion tank bit? Do you have one? A pressure gauge could be used for troubleshooting to see if the pressure rises to over 100 PSI after you use much hot water. If the pressure gets to 150, your new T+P valve will open too.

Hi, thanks. No, I did not. Going to have to call a plumber or HVAC guy (?). In the event I have this replaced any recommendations as to a good electric water heater would be appreciated! Specs of current on are attached.

 

[Reach4]

First, see if you have an expansion tank already. It would look something like this, but more often they hang down rather than sideways like this one:

You can get a pressure gauge for under $20 that will screw to your laundry faucet or the water heater drain valve. Some have a little hand to record the max.

Odds are, you just need to get that expansion tank. However while the plumber is there, also getting a new T+P valve does not add a lot to the price. Getting just the T+P valve changed, and getting a new pressure tank on a separate visit would cost significantly more.

 

[Jadnashua]

If the valve is opening on its own now, the tank is unlikely to explode! That only happens if the valve CANNOT open, and the problem seems to be yours won't stay closed. They open, as already said, for one of two reasons: pressure too high, or the temperature too high. Once they open (it could have been done manually), if there's some mineral buildup, they don't always reclose well. If the pressure was nearly boiling, I think you'd probably notice, but most people would not notice the subtle short-term rise in pressure that can cause the valve to open.

 

[Standardairconditioner]

We have had this water heater since at least 2000

Does that look like a rental unit? If so, you have grounds for them to replace the entire unit.

A 16 year old unit is nearing end of service. Newer ones will be more electrically efficient. Ask the rental company to see what your options are.

More like 24 years old. Installed in 1992. Terry