Hack plumber dilemma

[sawsaw]

Had a water heater installed by plumber. Told him I wanted the metal tap I had to be substituted for the cheapie tap on the bottom. Just prior to my departing to leave him to it, I noticed him taking an arc joint pliers to the plastic tap. A little while later, it was discovered the new tap did not fit the heater. Hmmm ... We're approaching overtime and, in a quick search, could not locate an acceptable tap. Told him to install the cheapie. With a finger in the cookie jar look, he showed me the mangled remains his arc joint pliers had left. With the clock ticking, I handed him a brass nipple and cap to use to have him stop his clock.
Now, I want to install a tap so I can "flush" the heater when desired.
The question is, with the incoming water tap and all house taps closed, at what force will the water exit the heater when I remove the cap from the brass nipple ... a rush, a slow stream, or somewhere between? If not much force, I may decide to leave the cap as is. If it's forceful, I'll look for a tap with matching threads. Tnx.

 

[Matt30]

You should of put a nipple and a ball valve, you now have a disaster waiting to happen. I would of never installed a cap.

 

[sawsaw]

Yes, I had thought about a ball valve, but the only available nipple was longer than desired, so a ball would have extended too far in the room. A hazard!
You didn't answer my question, though...

 

[Mr_David]

So you're calling him a hack because you wanted him to remove a plastic drain valve and install one you provided?

Or because he should have known better that he one you handed him to install was the wrong size before he took out the plastic one?

To answer your question, if you turn off the water to heater and open a faucet to relieve the pressure, then close it, you can pull the nipple without to much water flowing out. Just in case you have some crossover of cold back into hot system with everything off, to prevent the heater from building up pressure again before you pop the nipple off, turn off cold main also.

You just have to be quick with the new valve going back in.

 

[sawsaw]

Thanks for reply. I didn't report everything the plumber did to merit the title"hack," as that was not my reason for posting. The replacement tap came from the advisement of a big box store.
I presume, if I turn off the gas first, pressure should not be an issue ... ??

 

[SHR]

Turning off the gas will have no effect on the water pressure.

 

[havasu]

I'd recommend shutting off the gas. Let it cool for a few hours so you don't get blasted with hot, scalding water. Turn off the incoming cold water, and open up a hot water faucet inside. NOW CLOSE THE FAUCET. You can now safely open the cap, install the new spigot, then reverse what I said, fire it up, and you will be good to go.

 

[Matt30]

Better have a plan in place for if it doesn't go smoothly. You're going to have to find a place to dispurse all that water

 

[frodo]

I'd recommend shutting off the gas. Let it cool for a few hours so you don't get blasted with hot, scalding water. Turn off the incoming cold water, and open up a hot water faucet inside.now close the faucet You can now safely open the cap, install the new spigot, then reverse what I said, fire it up, and you will be good to go.

if you leave the faucet open, you are providing the tank a vent
if you close the faucet, take away the vent.
the heater will be air locked, when the cap is removed, it will ''glug''
instead of spraying every where
YOU HAVE TO BE QUICK

 

[havasu]

Thanks buddy, I forgot that important step. Thanks for the correction.

 

[sawsaw]

That's what I was presuming.
Thanks, Frodo.

 

[Mr_David]

Turning off the gas will have no effect on the water pressure.

It will if it's cooking. thermal expansion.

 

[Mr_David]

I'd recommend shutting off the gas. Let it cool for a few hours so you don't get blasted with hot, scalding water. Turn off the incoming cold water, and open up a hot water faucet inside. NOW CLOSE THE FAUCET. You can now safely open the cap, install the new spigot, then reverse what I said, fire it up, and you will be good to go.

Good point about the hot water. better safe than
If you relieve the pressure, then it will just glug out a little like Frodo said.

pretty sure I said close the faucet as well. But that important detail can easily be missed in my post.
Frodo's comment was more informative as to why you close it.

when I have to pull a plastic nipple on old a heater because it doesn't drain or is leaking I have a rag, a sturdy screw driver and a hammer nearby.

If you ever had one of those plastic drain cocks break apart while trying to remove it,

 

[SHR]

It will if it's cooking. thermal expansion.

If it's cooking yes. You would want to shut the water heater off first so it's not cooking

 

[geoffhazel]

I don't suppose the tank is set in an overflow pan? Because if it is, then if THAT has a drain on it somewhere it should catch a good deal of the water 'glugging' out of the tank. But yeah, be fast and accurate.