Water heater pipes...

I'm getting ready to run some new supply lines up to a new attic bathroom. I've got a great location to grab supply and send it upstairs. It's great because I've got easy access and I can just tee it up and sent it through the vertical wall that my dwv stack is coming down. It's a really appealing location.

The hot water pipe is just outside of the mechanicals room coming from the water heater. I assume it's fine to cut the pipe and put in a tee.

1) Will shutting off the main water valve or the valve controlling water emptying into the water heater do the trick? I hadn't considered it before, but will the water heater pump out hot water even with the main line off or the water intake to the water heater turned off? Can I just turn off the water heater?

2) I was planning on teeing up the cold water pipe heading to the water heater, too. I assume that's cool. I mean, that pipe is just carrying water to the water heater, right? Is there potential for me to burnout the heating element when I cut off this cold water supply?

Thanks for the help.

You can shut off the valve at the water heater, as long as it is working 100%, but you will still need to shut off the main coming into the house for the cold side so just turn off all the water to the house when you do it.

I would add valves after the T you install.

The water heater shouldn't drain down to the point of causing a problem but expansion of the water if the heater turns on could so just turn off the heater while you are doing the work.

Water heater

I agree with Cass, but I will add to his reply. I would use 3/4 tube to run your lines. Before you turn the heater on make sure that you bleed all the air out of your lines [electric water heaters do not like air pockets]. Luck.

With all due respect to Shacko when you turn on the water but B4 you turn on the heater run the hot water side and purge all the air out of the system, then turn on the heater.

air pockets

The only air pocket a water heater does not like is one around the upper element. Unless the water heater is drained, that air pocket is not going to occur. So the heater, either gas or electric, can be left on while the work is done, because without water flowing to cool it off, the heater is not going to turn on, nor will expansion be a factor if it should do so.

I misspoke...

I think I misspoke. There is a valve for the cold water leading to the water heater, but nothing for the hot water line out - at least, not before I want to tee in.

How can stop the hot water out of the water heater without a ball valve between it and where I want to tee? Shutting off the main won't stop that, will it?

thanks.

valve

IF the cold water valve is turned off, there is nothing to push the hot water out of the heater. But, if the hot water continues to run after that valve in cold water side is shut off, then you have a bad faucet somewhere in the house causing a bypass situation.

thanks...

Thanks for the explanation. I'll check it out.