This one has me completely confused. I installed a dishwasher in an island setup across from the main sink in the kitchen. I have added 1/2 inch copper piping from my hot water line under the kitchen sink in the basement. I tapped into the hot line going up to the kitchen sink. Total length was 7 feet of added piping straight pipe from the T connection that I soldered in. Now I have lost all but a little trickle of hot in my kitchen sink and, now this is the weird part... I have lost all but a little trickle of hot AND cold to my upstairs bathroom sink. These are the only two affected items in the system. Bathtub upstairs has full pressure, shower in the basement has full pressure, hotwater heater pressure relief valve has full pressure toilet has full pressure upstairs, kitchen sink has cold pressure but no hot. Unsure where to start here because the upstairs bathroom sink doesn't even tie into the line I tapped from. Not to mention the hot AND cold upstairs is trickling and only hot from the kitchen downstairs... then on top of that the hot AND cold in the bathtub right across from the sink that is having problems is having no problems what so ever...

Any ideas?:confused:

When you were tapping into the line where did you shut down the supply water, at a stop or at the main?

I tried to shut it off at a valve, but the stop valve let a trickle through. So I then shut it down at the main line... after the install I turned on the stop valve then turned on the main.

That puts the stop square in your sights. Close the stop ( I know it leaks) and open the line where it goes to the dishwasher, put a bucket over/under that open line and turn the stop on. Are you getting full pressure/volume?

Ok, I finally got to work on this today. Yes I get decent pressure (but probably not the best) at the dishwasher point when I do what you asked. I thought that I may have over soldered the tee where I tapped causing a clog. I cut that away to investigate only to find my solder job was perfect... I used one of those plastic quick connect tees in it's place... just so I knew for sure that I did not do anything to clog that connection. I turned on the water again and still have the same problems. When I use my dishwasher I can hear that it gets better pressure then my sink, but still tries to start then has to wait to fill up.
I still have little pressure in the sink on the second floor and full pressure in the bathtub on the second floor?? I only see one supply line that goes upstairs?? I'm so confused. Full pressure in the shower in the basement as well as the washer in the basement. Thinking about getting a pro's opinion.

Any assistance would be very helpful!

OK... I think you have a clogged aerator on second floor sink... Here, simply remove the aerator at the spout of the faucet by rotating counterclockwise until loosened and clean the aerator OR replace with a new one. This is actually quite common.

Second, you should remove the kitchen sink faucet stem assembly/cartridge/washer, etc. and investigate pressure there... Here, after removing guts and using a cloth to cover the faucet, pulse the hot water and see if that loosens debris from the hot water side... could just be gunk caught under the washer itself... maybe.. If that does not work then remove the riser from the hot water side of faucet and direct into bucket and see what water pressure looks like there... If that does not resolve or answer issue, then shut off the WATER MAIN SHUTOFF like you did previously and remove the stem assembly from the shutoff on the hot water side of your faucet and flush the hot water shutoff... here, with a friends help and 2 cell phones I would pulsate the main shutoff (friend) and I would catch the water in bucket under sink (you... be careful... hot water.. :)). This should tell you something... if pressure not full pressure then problem is even further back... but I doubt that... take your time and work your way backwards.. YOU will find the problem. GOOD LUCK... let us know how this worked out.

IF my answer was helpful, Please RATE MY ANSWER by clicking on RATE MY ANSWER!! Button below. Thank you!

Disconnect the supply line at the dishwasher and then shine a flashlight into the solenoid opening -- If it's plugged up with debris, then the faucet at the other locations are likely plugged up as well.

Most D/W solenoids, depending on the manufacturer, can be disassembled and cleaned fairly easily.

As for the sink faucets, a clean aerator isn't necessarily an indication that you're out of the woods debris wise -- Quite a few kitchen sink faucets have spring loaded valves in the supply lines (those that come with their own braided connectors) and at the faucet supply line connection point and it is common for debris to become lodged in these valves.

When this happens, I use an automotive pick set to pry out and clean the valves.

Another possibility to consider, something that happened to us about ten years ago, btw; Is that when you assembled your copper fittings you pushed the piping past the stop in a tee and blocked the opening.