p.s. this first floor shower is not being used obviously.

That's not a saddle valve, which is good news. It's a multi-turn stop valve, similar to what you might have under your sinks. Easy to replace. But you might just try this first: open the valve fully and see if it stops the leak. (if partially open, they leak more easily).

As for the elbow, I think it will be fine so I'd just leave it be.

I'm in N. Va, too, but I simply suggest going to a local plumbing supply and asking for recommendation.

One more thing. If you do end up needing the valve replaced then certainly have the elbow replaced at the same time since the pipe has to be drained anyway. I'd just stick with copper.

But if the valve ends up holding water, then leave the elbow alone for now. It's more than likely going to be fine.

Thanks for your advice. Ok, tomorrow I will open up the valve completely and then tighten it carefully back down. I guess this assumes it may have been left partially open when the humidifier was turned on and allowed water out at the union. I'll let you know what happens.

I don't like a badly corroded water pipe like that: seems like an accident waiting to happen at an in-opportune time. I'm not a big fan of soldering (fire hazard) as I've had overhead wood charred by no wet back. I understand that carbonization does happen. Good news: I'm beginning to prompt myself to turn off the main water valves before major departures.

Also, you didn't mention which connection on the valve is leaking. Is it from the stem or the compression coupling that connects to the tubing? Either way, you might be able to snug up the nut just a bit while holding the valve with a second wrench. (take off the handle temporarily if it's in the way of holding the valve). Good luck.

(Full disclosure: I'm a handyman, not a pro plumber.)

I did not notice a mention of your water supply. I suspect that you have a well. I have one well that ruins brass valves within a year. I spent big dollars on some PVC true-union ball valves and changed the piping to non-metallic. No further problems in the almost 20 years since then.

Thanks for your comment, bus driver. Actually, we're on city water :/. I have checked their analysis (where they say minerals are within acceptable limits) but the evidence suggests else wise.

I'm looking into a water softener system. Our plumbing company (big co.) was going to sell me a simple single filter system for placement after the main water intake, but when I researched it, it was already discontinued (must have been on their truck), cost $120 or so, and they were charging $600 to put it in. yikes! But yes, that's one reason I'm wondering about changing to non-metallic piping.

Any other ideas or input? I can't research a RO whole house system just yet as doing flues and chimneys just now. Busy.

It's the stem of the multi turn valve that shot water out when the humidifier was started up. The humidifier compression coupling and tubing was run off the hot water pipe above the Ruud gas water heater.

I am going to call in the plumbing company. Time for the water heater to be drained and flue checked anyway and guess that corroded T should be changed out.

I have not previously entered into this discussion because "Homebound" had already given the correct answers, but let me add a bit of information to what Homebound mentioned.

Sparklingwater mentioned that the leak is at the base of the stem in the angle stop valve. He/she also asked if there is a way to lubricate the stem to make it easier to turn?

I suspect that the angle stop had previously been turned off and the HVAC tech turned it on to check out the humidifier and while doing so the leak was noticed.

(see attached photo). If you look at the valve you will note a nut on the top of the valve where the handle stem enters the valve body. Under that nut there is a packing that is made out of graphite, teflon or perhaps neoprene that surrounds the stem shaft and as the nut is tightened the packing is squeezed against the shaft to form a water tight seal. When trying to rotate the handle on an old valve you can slightly loosen that nut (generally about a 1/4 turn) and it will loosen the shaft making it easier to turn the handle and once you get the handle to the desired location, either full open or full closed, you can then tighten that nut again to stop any leak that might form. If you cannot stop the leak by tightening that nut you must then replace the valve. (for larger valves we can replace the packing but since angle stop valves are only about $3 for the complete valve, don't expect your local hardware to carry replacement parts for it).

That valve is on the hot water system so if you have to change the valve you don't have to drain the whole house, just the hot water system until it is drained below that valve. To drain it down sufficiently you could turn the cold water supply to the water heater off, then if you have a laundry connection of utility sink that is below that valve you could open a hot water faucet on the floor above to vent the line and open the hot water valve at tne sink or laundry and let it run until the water stops. If you don't have a hot water faucett below that level you will then have to turn the gas off to the water heater and drain the water heater until the water is below that valve.

That valve is mounted on the vertical copper stub by means of a compression fitting on the bottom end of the valve. Unscrew the compression nut and let it drop down to the tee, then twist the valve a bit with a wrench to loosen it, and it will lift right off. You will then see a brass ferrule surrounding the pipe about 1/2" from the end. In many cases you can remove the compression nut and ferrule from a new valve, then set the new valve down in place and tighten the existing compression nut to lock the new valve on and seal the joint. If it won't seal using the existing compression nut and ferrule you then unscrew the existing nut again and cut the copper stub just below the existing ferrule. You will find a mini tubing cutter will work the best here, but also keep in mind that you have to cut is high enough on the stub to allow the valve to set down tight without hitting the tee. Once you have the pipe cut. clean the pipe with an emery cloth, then put the new compression nut on the pipe, open threaded side up, then slide the new ferrule on the pipe and slip it down about 3/8". Now place the new valve on the stub and push it down tight, the ferrule will slide down to the correct position as you push the valve down. Now slide the compression nut up and screw it on the bottom of the new valve and while holding the valve body with one wrench, thorougly tighten the compression nut with another wrench to lock it in place.

Now in regards to that corroded elbow. First off, I would be curious to know what they are draining with that line?

I WOULD NOT be worried about that corrosion because it has nothing to do with the water in the line. That corosion resulted from improper installation of the elbow. That white corrosion is a result of excess flux left on the line when they soldered it, however by now the flux has long since dried out and it is no longer a problem.

After reviewing the photos I beleive the entire installation was done as a DIY project. Notice the elbow on the left end of the horizontal line where the angle stop is located. That dark coloration on the outside of the curve indicates that they got the pipe too hot while soldering. The same is evident on the side inlet and pipe on the tee right above it, as well as the excess solder on the pipe directly below the tee. Those are all indications of a very amateur soldering job.

Next look at the top of the water heater. The copper lines are connected directly to the water heater, but code has required a dielectric coupling since the late 1970's and code requires a union on both water lines since the mid 80's.

Now I would not recommend bothering to add the dielectric nipples or unions now, but keep in mind that the next time you have to replace the water heater, make sure they are installed.

For the moment I believe if you just open or close that angle stop, then tighten the stem packing nut a bit you will be fine and their is no reason to spend your money calling a plumber.

Thank you Lazypup and bus_man and homebound. You have helped me understand better what the stuff on the pipes is and how it may have come about. We've been here close to twenty years, the gas water heater was installed in 2003 by a large reputable plumbing company, and all work in the basement work room has only been done by certified qualified plumbers and hvac companies while I've lived here. But last night (after watching Tim, the builder on gas water heaters), I went down and looked again at the Ruud, and noticed the lack of dielectric coupling put in in 2003. I don't get it. I'm a woman btw trying to address house issues more but pretty stumped at times, but whatever. Life is good for us. Thanks for explaining about the hot water usage side and more.

I'm wondering if anyone knows a smallish plumbing company here in Northern Virginia that practices to code? Not trying to be off-putting to respected plumbers.

"Now in regards to that corroded elbow. First off, I would be curious to know what they are draining with that line?"

That elbow abutts a hot water pipe that runs to the vertical hot water pipe direct from the gas hot water heater which sits to the right. The second part of the elbow pipe continues hot water off to the bathroom on the other side of the house. Yes, that iron coupling looks old, maybe before 1970's code change. Compromising the situation further was the PO overlook of the shower liner in the first floor half bath, which I use as a utility space now but will be taking that bath down for redo eventually.

Thank you all for continued words of wisdom: I'll see what I can do.